Fri, 04 Jul 2008 23:50:20 BST CiteULike: Tag rf http://www.citeulike.org/tag/rf CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/rtysondvm/article/1233530 <i>J Endourol, Vol. 19, No. 2. (March 2005), pp. 242-247.</i><br /><br />PURPOSE: To investigate the temperature distribution and geometry of lesions created by radiofrequency (RF) tissue ablation. MATERIALS AND METHODS: We developed an ex-vivo thermal model based on the ability of egg whites to coagulate at 62 degrees to 65 degrees C. This property allows us to observe and record the formation of "lesions" created by different commercially available RF generators and probes. RESULTS: The lesions created by the Radionics Cool-Tip RF system were mostly cylindrical or barrel-shaped, while RITA StarBurst XL and StarBurst XLi electrodes produced cone-like or mushroom-shaped lesions. The time required to achieve maximum lesion size was between 3 and 5 minutes in most trials. The formation of lesions stopped when thermodynamic equilibrium was achieved. CONCLUSIONS: The geometry of lesions does not correlate precisely with manufacturer reports, which describe spherical lesions for both RF systems. The 12-minute treatment cycle recommended by company's algorithm may not be necessary because lesion formation was completed and thermodynamic equilibrium was reached significantly earlier. We believe the results of our study may be useful in better understanding the RF ablation process, better planning, and improvement of clinical outcome. Geometry and temperature distribution during radiofrequency tissue ablation: an experimental ex vivo model. L Lobik RJ Leveillee MF Hoey doi:10.1089/end.2005.19.242 J Endourol, Vol. 19, No. 2. (March 2005), pp. 242-247. 2007-04-18T11:33:10-00:00 2005 J Endourol 0892-7790 19 2 242 247 rf http://www.citeulike.org/user/rmerz/article/786188 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 23, No. 12. (1975), pp. 1048-1049.</i><br /><br />This short paper describes a novel method of generating a pulse sequence using step-recovery diodes (SRDs) shunting a transmission line. Individual pulses in the train may have rise times less than 60 ps with amplitudes greater than 10 V. The many potential applications of the device include a short RF pulse generator, an FM generator, and a high-speed word generator. Picosecond-Pulse Sequential Waveform Generation (Short Papers) HM Cronson Microwave Theory and Techniques, IEEE Transactions on, Vol. 23, No. 12. (1975), pp. 1048-1049. 2006-08-04T13:23:03-00:00 1975 Microwave Theory and Techniques, IEEE Transactions on 23 12 1048 1049 picosecond pulse_generation rf srd http://www.citeulike.org/user/rmerz/article/786187 <i>Electronics Letters, Vol. 37, No. 8. (2001), pp. 504-506.</i><br /><br />A simple, compact, low-cost picosecond pulse generator has been developed using a coplanar waveguide and step-recovery diode. This pulse generator generates pulses of 154 ps pulsewidth and 3.5 V amplitude from an input square wave of 10 MHz repetition rate. The generated pulses have low ringing level and good symmetry. The simplicity, compactness, low cost, and good performance of the developed pulse generator make it attractive for low-cost time-domain microwave systems Uniplanar picosecond pulse generator using step-recovery diode JS Lee C Nguyen Electronics Letters, Vol. 37, No. 8. (2001), pp. 504-506. 2006-08-04T13:20:46-00:00 2001 Electronics Letters 37 8 504 506 picosecond pulse_generation rf srd http://www.citeulike.org/user/rmerz/article/786166 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 39, No. 7. (1991), pp. 1194-1204.</i><br /><br />The GaAs nonlinear transmission line (NLTL) is a monolithic millimeter-wave integrated circuit consisting of a high-impedance transmission line loaded by reverse-biased Schottky contacts. The engineering of functional monolithic NLTLs is considered. Through generation of shock waves on the NLTL, the authors have generated electrical step functions with approximately 5 V magnitude and less than 1.4 ps fall time. Diode sampling bridges strobed by NLTL shock-wave generators have attained bandwidths approaching 300 GHz and have applications in instruments for millimeter-wave waveform and network measurements. The authors discuss the circuit design and diode design requirements for picosecond NLTL shock-wave generators and NLTL-driven sampling circuits.<<ETX>> GaAs nonlinear transmission lines for picosecond pulse generation and millimeter-wave sampling MJW Rodwell M Kamegawa R Yu M Case E Carman KS Giboney Microwave Theory and Techniques, IEEE Transactions on, Vol. 39, No. 7. (1991), pp. 1194-1204. 2006-08-04T12:24:51-00:00 1991 Microwave Theory and Techniques, IEEE Transactions on 39 7 1194 1204 picosecond pulse_generation rf http://www.citeulike.org/user/rmerz/article/786165 <i>Proceedings of the IEEE, Vol. 54, No. 2. (1966), pp. 335-337.</i> Method of generating sub-nanosecond pulses CF Vasile Proceedings of the IEEE, Vol. 54, No. 2. (1966), pp. 335-337. 2006-08-04T12:16:47-00:00 1966 Proceedings of the IEEE 54 2 335 337 pulse_generation rf srd http://www.citeulike.org/user/rmerz/article/789801 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 54, No. 1. (2006), pp. 285-293.</i><br /><br />Development of a new sub-nanosecond monocycle pulse transmitter with tunable pulse duration for short-range low-power ultra-wideband radar and communication systems is presented along with detailed design and analysis. The developed pulse transmitter is simple, compact, and can be realized using planar or uniplanar integrated circuits. A novel RC coupling circuit along with a high driving current, provided by a high-speed amplifier and buffers, are used to obtain an increase in the output power. A decoupling circuit is implemented to reduce ringing on the monocycle pulse and provide necessary pulse clamping. Tuning of the output monocycle-pulse duration is achieved by using two distributed delay lines, coupled together by the decoupling network, each spatially loaded with antiparallel p-i-n diodes that are alternately switched on and off. Measurement results show tunable monocycle pulse durations in range of 0.4-1.2 ns, approximately corresponding to the operating frequency range of 0.15-3.7 GHz, and 200-400 mW of pulse peak power. The calculated and measured pulse durations also agree reasonably well. On the development of a compact sub-nanosecond tunable monocycle pulse transmitter for UWB applications Jeongwoo Han C Nguyen Microwave Theory and Techniques, IEEE Transactions on, Vol. 54, No. 1. (2006), pp. 285-293. 2006-08-08T12:22:09-00:00 2006 Microwave Theory and Techniques, IEEE Transactions on 54 1 285 293 picosecond pulse_generation rf srd http://www.citeulike.org/user/rmerz/article/783053 <i>Proceedings of the IEEE, Vol. 57, No. 7. (1969), pp. 1250-1259.</i><br /><br />A simple charge-controlled switching model describes most fundamental aspects of the step recovery diode. However, it is shown that switching speed and the associated loss are related to the width of the i layer and to the doping level. A switching model appropriate for general computer use is given, and examples of its application are shown in pulse and harmonic generator circuits. Physical modeling of the step recovery diode for pulse and harmonic generation circuits JL Moll SA Hamilton Proceedings of the IEEE, Vol. 57, No. 7. (1969), pp. 1250-1259. 2006-08-02T14:44:11-00:00 1969 Proceedings of the IEEE 57 7 1250 1259 pulse_generation rf srd http://www.citeulike.org/user/rmerz/article/783051 <i>Solid-State Circuits Conference. Digest of Technical Papers. 1966 IEEE International, Vol. IX (1966), pp. 66-67.</i> Impulse-shunt mode harmonic generation R Hall S Hamilton S Krakauer Solid-State Circuits Conference. Digest of Technical Papers. 1966 IEEE International, Vol. IX (1966), pp. 66-67. 2006-08-02T14:38:07-00:00 1966 Solid-State Circuits Conference. Digest of Technical Papers. 1966 IEEE International IX 66 67 pulse_generation rf srd http://www.citeulike.org/user/rmerz/article/786257 <i>Wireless Communication Technology, 2003. IEEE Topical Conference on (2003), pp. 441-442.</i><br /><br />Various low-cost, compact planar ultra-wideband (UWB), ultra-short pulse generators have been developed using step recovery and PIN diodes and MESFET. These include fixed and electronically tunable pulse generators. Fixed pulses ranging from 115 to 300 ps and tunable pulses Varying from 300 to 800 ps have been demonstrated experimentally and theoretically. Good agreement between measured and calculated results is also achieved. These pulse generators find applications in UWB communications systems, both transmitter and receiver. Recent development of SRD- and FET-based sub-nanosecond pulse generators for ultra-wideband communications Jeong-Woo Han Meng Miao Cam Nguyen Wireless Communication Technology, 2003. IEEE Topical Conference on (2003), pp. 441-442. 2006-08-04T15:16:23-00:00 2003 Wireless Communication Technology, 2003. IEEE Topical Conference on 441 442 picosecond pulse_generation rf srd http://www.citeulike.org/user/rmerz/article/796081 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 53, No. 6. (2005), pp. 1875-1882.</i><br /><br />A new compact low-cost sampling mixer with internal local strobe-pulse generator for (carrierless) ultra-wideband (UWB) applications, especially for sub-sampling of UWB video pulse signals, is presented along with detailed design information. The sampler employs a double-sided planar structure to facilitate interface with the strobe-pulse generator and the baseband circuit without using wire connections or air bridges, enabling hybrid microwave integrated-circuit integration with significant reduction in assembly effort. A novel coupling structure for both coupling and termination of the RF and local-oscillator signals to the Schottky-diode sampling bridge was designed to suppress ringing in the strobe pulse signal, resulting in harmonic-distortion reduction in the baseband output signal. Development of strobe-pulse generators using step recovery diodes for good output power efficiency is also presented along with design information for relatively low clock frequencies. The developed sampler achieves an unprecedented conversion loss of 4.5-7.5 dB (without a baseband amplifier) and conversion gain from 6.5 to 9.5 dB (with an amplifier) over a 5.5-GHz RF bandwidth, a dynamic range of over 50 dB, and low harmonic distortion in the baseband output. A new intrinsic conversion-loss equation that allows the sampler's conversion loss and operating RF bandwidth to be predicted accurately was also derived. Coupled-slotline-hybrid sampling mixer integrated with step-recovery-diode pulse generator for UWB applications Jeongwoo Han Cam Nguyen Microwave Theory and Techniques, IEEE Transactions on, Vol. 53, No. 6. (2005), pp. 1875-1882. 2006-08-10T14:32:11-00:00 2005 Microwave Theory and Techniques, IEEE Transactions on 53 6 1875 1882 picosecond pulse_generation rf srd http://www.citeulike.org/user/rmerz/article/786226 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 49, No. 6. (2001), pp. 1126-1129.</i><br /><br />This paper presents the development of a new monocycle pulse generator and pulse-to-monocycle-pulse transformer operating in the subnanosecond regime. These circuits employ Schottky diodes, step recovery diodes, and simple charging and discharging circuitry, and are completely fabricated using coplanar waveguides. Simple transient analysis and design of the circuits are presented along with their operating principles. The pulse-to-monocycle-pulse transformer converts a 1 V 300 ps pulse into a 0.7-V 350 ps monocycle pulse. The monocycle pulse generator produces a monocycle pulse having 333 ps pulsewidth and more than 2 V from an input square wave of 10 MHz repetition rate. The generated monocycle pulses have very symmetrical positive and negative portions and low ringing level New uniplanar subnanosecond monocycle pulse generator and transformer for time-domain microwave applications Jeong Lee C Nguyen T Scullion Microwave Theory and Techniques, IEEE Transactions on, Vol. 49, No. 6. (2001), pp. 1126-1129. 2006-08-04T14:15:57-00:00 2001 Microwave Theory and Techniques, IEEE Transactions on 49 6 1126 1129 picosecond pulse_generation rf srd http://www.citeulike.org/user/rmerz/article/795992 <i>Microwave and Wireless Components Letters, IEEE [see also IEEE Microwave and Guided Wave Letters], Vol. 12, No. 6. (2002), pp. 206-208.</i><br /><br />We introduce a new ultra-wideband (UWB), ultra-short, step recovery diode monocycle pulse generator. This pulse generator uses a simple RC high-pass filter as a differentiator to generate the monocycle pulse directly. The pulse-shaping network employs a resistive circuit to achieve UWB matching and substantial removal of the pulse ringing, and rectifying and switching diodes to further suppress the ringing. An ultra-short monocycle pulse of 300-ps pulse duration, -17-dB ringing level, and good symmetry has been demonstrated. Good agreement between the measured and calculated results was achieved A new ultra-wideband, ultra-short monocycle pulse generator with reduced ringing Jeongwoo Han Cam Nguyen Microwave and Wireless Components Letters, IEEE [see also IEEE Microwave and Guided Wave Letters], Vol. 12, No. 6. (2002), pp. 206-208. 2006-08-10T13:42:47-00:00 2002 Microwave and Wireless Components Letters, IEEE [see also IEEE Microwave and Guided Wave Letters] 12 6 206 208 picosecond pulse_generation rf srd http://www.citeulike.org/user/rmerz/article/786191 <i>Wireless and Microwave Technology, 2005. WAMICON 2005. The 2005 IEEE Annual Conference (2005), pp. 43-46.</i> A discrete fully logical and low-cost sub-nanosecond UWB pulse generator J Schwoerer B Miscopein B Uguen G El-Zein Wireless and Microwave Technology, 2005. WAMICON 2005. The 2005 IEEE Annual Conference (2005), pp. 43-46. 2006-08-04T13:27:13-00:00 2005 Wireless and Microwave Technology, 2005. WAMICON 2005. The 2005 IEEE Annual Conference 43 46 picosecond pulse_generation rf srd http://www.citeulike.org/user/Quarem/article/2759452 <i>Vacuum, Vol. 29, No. 10. (1979), pp. 341-350.</i><br /><br />To calculate impedance matching networks for capacitively coupled rf excited plasmas (as used for sputtering and some type of chemical reactors) it is necessary to know the values of the plasma parameters, i.e. the capacitance and the conductance of the discharge and the variation of these with the operating conditions of the system, i.e. the pressure, the frequency and the input power. The paper presented here gives information on the foregoing and shows how the results can be used to design suitable matching networks. To provide basic information on the glow discharge conditions experiments have been carried out using an rf power supply with one side of the matching network connected via a blocking capacitor to an electrode and the remaining side grounded. This system has been operated under various conditions, i.e. the frequency has been varied between 2 and 14 MHz, the air pressure from 1 × 10-1 down to 5 × 10-3 torr and the input power density from 0.5 to 2 W cm-2. The results obtained for 14 MHz are in close agreement with those reported for 13.56 MHz by Logan et al1. From the values obtained for the plasma parameters different types of matching network (L, [pi], T> and tuned transformer) have been calculated. The design equations for these networks are presented with calculated and tested examples to demonstrate their application. The procedure used, although common electrical engineering practice, should with the measured data be of value to those undertaking rf system design without experience of matching conditions. Experimental and design information for calculating impedance matching networks for use in rf sputtering and plasma chemistry H Norström doi:10.1016/0042-207X(79)90312-9 Vacuum, Vol. 29, No. 10. (1979), pp. 341-350. 2008-05-06T00:05:32-00:00 1979 Vacuum 29 10 341 350 rf sputter http://www.citeulike.org/user/OlivierL/article/2814392 <i>Microwave Conference, 2003. 33rd European, Vol. 1 (2003), pp. 241-244 Vol.1.</i><br /><br />Breaking-up the limitations of VNAs for RF non-linear measurements, the LSNA (large signal network analyser) allows time domain characterizations of full two-port active devices. We demonstrate here some capabilities of the LSNA for pulsed RF signals. We establish a stroboscopic mode based on 3 different sampling techniques. This approach is suitable for repetitive pulsed RF signals. Time-domain pulsed large-signal non-linear characterization of microwave transistors C Charbonniaud JP Teyssier R Quere Microwave Conference, 2003. 33rd European, Vol. 1 (2003), pp. 241-244 Vol.1. 2008-05-19T22:18:06-00:00 2003 Microwave Conference, 2003. 33rd European 1 241 244 Vol.1 rf vna http://www.citeulike.org/user/negarehsan/article/2800306 <i>Design Automation Conference, 2003. Proceedings (2003), pp. 73-78.</i><br /><br />In this paper, we discuss the many issues around the system and circuit design of advanced RF front ends for mobile, wireless and consumer RF applications. After an analysis of the application trends, technology choices linked to the different systems solutions is discussed. RF front end application and technology trends PW Hooijmans Design Automation Conference, 2003. Proceedings (2003), pp. 73-78. 2008-05-14T23:46:22-00:00 2003 Design Automation Conference, 2003. Proceedings 73 78 front-end rf http://www.citeulike.org/user/msterner/article/1294578 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 49, No. 11. (2001), pp. 2099-2104.</i><br /><br />A novel millimeter-wave packaging structure was developed in which a micromachined low-loss planar component and flip-chip devices were integrated on a silicon substrate. A low-loss planar filter was achieved on a 7-mm-square silicon substrate employing an inverted microstrip line and a unique resonator. High attenuation in the stopband was also obtained by introducing a pole control technique. Fabrication of a compact K-band receiver front-end incorporating a built-in filter was realized using multilayered benzocyclobutene (BCB) and flip-chip bonding techniques. Furthermore, we propose an alternative BCB suspended structure and demonstrate a planar antenna for Ka-band applications. These technologies bring to reality high-performance compact packaged systems in millimeter-wave region applications Packaging using microelectromechanical technologies and planar components K Takahashi U Sangawa S Fujita M Matsuo T Urabe H Ogura H Yabuki Microwave Theory and Techniques, IEEE Transactions on, Vol. 49, No. 11. (2001), pp. 2099-2104. 2007-05-14T08:31:04-00:00 2001 Microwave Theory and Techniques, IEEE Transactions on 49 11 2099 2104 mems rf waveguide http://www.citeulike.org/user/msterner/article/1294573 <i>Microwave and Millimeter Wave Technology Proceedings, 1998. ICMMT '98. 1998 International Conference on (1998), pp. 615-618.</i><br /><br />The micromachining of silicon is broadly proposed for the fabrication of substrates and waveguides at millimeter wavelengths. This paper presents the results of the fabrication of finned diamond-shaped waveguides by way of EDP anisotropic etching of silicon. A guide is fabricated in two halves by etching V-grooves in 〈100〉 silicon wafers. The etched faces of the wafers were metalized through evaporation of about 0.3 microns of gold followed by gold electroplating of approximately 1.5 microns. Metallic fins were formed on a thin membrane which was sandwiched between the two halves of the waveguide. Measurements of the dispersion curve were taken and compared with numerical calculations using the FEM technique. The comparison showed a very good agreement. An empty diamond-shaped waveguide manifests a single-mode bandwidth that is significantly less than that of a counterpart rectangular waveguide, but the bandwidth can be restored to be comparable to that of the rectangular guide through the introduction of fins Micromachined waveguide for millimeter wave applications BA Shenouda Wilson Microwave and Millimeter Wave Technology Proceedings, 1998. ICMMT '98. 1998 International Conference on (1998), pp. 615-618. 2007-05-14T08:23:20-00:00 1998 Microwave and Millimeter Wave Technology Proceedings, 1998. ICMMT '98. 1998 International Conference on 615 618 mems rf waveguide http://www.citeulike.org/user/msterner/article/1294565 <i>Electronics, Communications and Computers, 2006. CONIELECOMP 2006. 16th International Conference on (2006), pp. 15-15.</i><br /><br />Several different fabrication techniques and materials have been proposed for making low loss high performance micromachined transmission lines. In this paper a review of several micromachined transmission lines that have been proposed over the last years are classified into four types according to their physical structure and their power losses addressed. Micromachined Transmission Lines for Millimeter-Wave Applications I Llamas-Garro A Corona-Chavez Electronics, Communications and Computers, 2006. CONIELECOMP 2006. 16th International Conference on (2006), pp. 15-15. 2007-05-14T08:13:28-00:00 2006 Electronics, Communications and Computers, 2006. CONIELECOMP 2006. 16th International Conference on 15 15 mems rf http://www.citeulike.org/user/msterner/article/1296677 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 52, No. 12. (2004), pp. 2651-2657.</i><br /><br />This paper presents a novel concept for an RF microelectromechanical systems (MEMS) waveguide switch. The proposed switch employs a ridge waveguide integrated with MEMS rotary actuators based on a thermal plastic deformation approach. The switch promises to be useful in high-power applications, as well as in millimeter-wave applications. Two switch implementations are presented: one with a waveguide interface and the other with a coplanar-waveguide interface for wide-band applications. Electromagnetic simulation results are presented showing the ultimate potential of the proposed concept. Both switch implementations have been fabricated and tested. The achievable measured results are very encouraging and demonstrate the feasibility of such novel types of MEMS switches. The power-handling capability of the switch is also investigated both theoretically and experimentally. RF MEMS waveguide switch M Daneshmand RR Mansour N Sarkar Microwave Theory and Techniques, IEEE Transactions on, Vol. 52, No. 12. (2004), pp. 2651-2657. 2007-05-15T08:23:52-00:00 2004 Microwave Theory and Techniques, IEEE Transactions on 52 12 2651 2657 funny mems rf waveguide http://www.citeulike.org/user/msterner/article/1728041 <i>Sensors and Actuators A: Physical, Vol. 121, No. 1. (31 May 2005), pp. 187-196.</i><br /><br />A dc 6 GHz single-pole double-throw (SPDT) switching circuit that employs lateral metal-contact micromachined switches is investigated. The lateral metal-contact switch consists of a set of quasi-finite ground coplanar waveguide (FGCPW) transmission lines and a high-aspect-ratio cantilever beam. A single-pole single-throw (SPST) lateral micromachined switch has an insertion loss of 0.08 dB and a return loss of 32 dB at 5 GHz. The isolation is 32 dB at 5 GHz. The measured insertion loss of the SPDT switching circuit is below 0.75 dB, whereas the return loss is higher than 19 dB at 5 GHz. The isolation at 5 GHz is 33 dB. Pull-in voltage of the switch is 23.3 V and switching time is 35 [mu]s. The size of the SPDT switching circuit is 1.2 mm x 1.5 mm. A main advantage of this circuit structure is simple fabrication process with high yield (>90%) based on the deep reactive ion etching (DRIE) technique of silicon-on-insulator (SOI) wafer and shadow mask technology. A single-pole double-throw (SPDT) circuit using lateral metal-contact micromachined switches M Tang AQ Liu A Agarwal ZS Liu C Lu doi:10.1016/j.sna.2004.12.017 Sensors and Actuators A: Physical, Vol. 121, No. 1. (31 May 2005), pp. 187-196. 2007-10-04T17:46:02-00:00 2005 Sensors and Actuators A: Physical 121 1 187 196 mems rf spdt switch waveguide http://www.citeulike.org/user/msterner/article/1294636 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 46, No. 6. (1998), pp. 762-768.</i><br /><br />This paper describes the development and characterization of a new class of Si-micromachined lines and circuit components for operation between 2-110 GHz. In these lines, which are a finite-ground coplanar-waveguide (FGC) type, Si micromachining is used to remove the dielectric material from the aperture regions in an effort to reduce dispersion and minimize propagation loss. Measured results have shown a considerable loss reduction to levels that compare favorably with those of membrane lines and rectangular waveguides. Micromachined FGC lines have been used to develop V- and W-band bandpass filters. The W-band micromachined FGC filter has shown a 0.8-dB improvement in insertion loss at 94 GHz over a conventional FGC line. This approach offers an excellent alternative to the membrane technology, exhibiting very low loss, no dispersion, and mode-free operation without using membranes to support the interconnect structure Si-micromachined coplanar waveguides for use in high-frequency circuits KJ Herrick TA Schwarz LPB Katehi Microwave Theory and Techniques, IEEE Transactions on, Vol. 46, No. 6. (1998), pp. 762-768. 2007-05-14T09:24:03-00:00 1998 Microwave Theory and Techniques, IEEE Transactions on 46 6 762 768 mems rf waveguide http://www.citeulike.org/user/msterner/article/1294631 <i>Micro Electro Mechanical Systems, 2004. 17th IEEE International Conference on. (MEMS) (2004), pp. 801-804.</i><br /><br />This paper presents a novel low-loss (1.74 dB) 3-pole Butterworth distributed filter operating in the Ka-band with a center frequency of 29 GHz. The filter has a compact 6 mm square footprint and is designed using 3-dimensional (3D) micromachined integrated coax. The integrated coax transmission lines are made of forty-one nickel layers and fabricated using a selective electrochemical metal deposition process (EFAB/spl trade/). Full-wave simulations of the filter using Ansoft HFSS show very good agreement on insertion loss compared with measured results. Using the EFAB/spl trade/, we have been able to produce low-loss, all-metal, completely shielded transmission lines with small bend radii and no inter-line coupling. A compact low-loss Ka-band filter using 3-dimensional micromachined integrated coax RT Chen ER Brown CA Bang Micro Electro Mechanical Systems, 2004. 17th IEEE International Conference on. (MEMS) (2004), pp. 801-804. 2007-05-14T09:20:49-00:00 2004 Micro Electro Mechanical Systems, 2004. 17th IEEE International Conference on. (MEMS) 801 804 mems rf waveguide http://www.citeulike.org/user/msterner/article/1294625 <i>Micro Electro Mechanical Systems, 2006. MEMS 2006 Istanbul. 19th IEEE International Conference on (2006), pp. 870-873.</i><br /><br />In this paper, a novel monolithic surface micromachined half-coaxial transmission line filter was designed, fabricated and measured. The band pass filter presented here has a unique ground structure compared to the other research groups -the suspended ground plane is 100 ptm over the center conductor. The high Q<inf>0</inf>results from this large gap and an additional reduction of loss is obtained by using quartz substrates. The filter is a 3-pole, 500 fractional bandwidth, bandpass filter centered at 31.75 GHz, consisting of three capacitively coupled resonators composed of half coaxial transmission lines, which are connected to input and output transitions designed to interface with external CPW probes for measurement. The spacing between resonators and the input and output coupling to the filter were calculated from a low pass filter prototype. The fabricated filter has a length of 13 mm and width of 1 mm. A 100-ptm-thick sacrificial layer was made by JSR THB-15IN photoresist. Suspended Au ground plane was supported at the substrate by electroplating process. The pass band return and insertion loss were -10.07 dB at 31.1 GHz and -2.83 dB at 32.0 GHz, respectively. In order to extract total losses of the proposed half coaxial transmission line, we fabricated and measured single resonators. A maximum Q<inf>0</inf>value of 153 was obtained and these Q values showed the potential of this filter structure, because much higher air gap can be obtained with the same process, resulting in further increase of Q<inf>0</inf>. Measured loss from the transition was around -0. A Monolithic Surface Micromachined Half-Coaxial Transmission Line Filter Yongsung Kim I Llamas-Garro Chang-Wook Baek Yong-Kweon Kim Micro Electro Mechanical Systems, 2006. MEMS 2006 Istanbul. 19th IEEE International Conference on (2006), pp. 870-873. 2007-05-14T09:16:08-00:00 2006 Micro Electro Mechanical Systems, 2006. MEMS 2006 Istanbul. 19th IEEE International Conference on 870 873 mems rf waveguide http://www.citeulike.org/user/msterner/article/1294619 <i>Microwaves, Antennas and Propagation, IEE Proceedings -, Vol. 152, No. 3. (2005), pp. 155-159.</i><br /><br />A suspended coaxial transmission line with an air propagation medium is presented. The transmission line is made only of metal, thereby avoiding dielectric and radiation losses. Short-circuit stubs suspend the centre conductor of the coaxial structure which is used in the design of two dual-mode narrowband microwave filters. Stacked layers of copper sheets are used to form the square coaxial transmission line, which has low loss and low dispersion. Air-filled square coaxial transmission line and its use in microwave filters I Llamas-Garro MJ Lancaster PS Hall Microwaves, Antennas and Propagation, IEE Proceedings -, Vol. 152, No. 3. (2005), pp. 155-159. 2007-05-14T09:06:42-00:00 2005 Microwaves, Antennas and Propagation, IEE Proceedings - 152 3 155 159 mems rf waveguide http://www.citeulike.org/user/msterner/article/1295209 <i>Microwave and Wireless Components Letters, IEEE, Vol. 11, No. 2. (2001), pp. 59-61.</i><br /><br />A new type of overlay coplanar waveguide (CPW) structure, “inverted overlay CPW (IOCPW)” is developed using micromachining techniques to provide easy means of airbridge connection between the ground planes, as well as to achieve low losses over wide impedance ranges. Measured IOCPW showed less than 1 dB/cm loss at 50 GHz over a wide impedance range from 25 to 80 Ω. It also offered low effective dielectric constant, and insensitivity to the substrate losses. Wide impedance ranges and simple process steps make IOCPW a promising uniplanar transmission line medium for mm-wave monolithic applications Low-loss micromachined inverted overlay CPW lines with wide impedance ranges and inherent airbridge connection capability Youngwoo Kwon Hong-Teuk Kim Jae-Hyoung Park Yong-Kweon Kim Microwave and Wireless Components Letters, IEEE, Vol. 11, No. 2. (2001), pp. 59-61. 2007-05-14T14:35:39-00:00 2001 Microwave and Wireless Components Letters, IEEE 11 2 59 61 mems rf waveguide http://www.citeulike.org/user/msterner/article/1294613 <i>High Speed Semiconductor Devices and Circuits, 1991., Proceedings IEEE/Cornell Conference on Advanced Concepts in (1991), pp. 252-260.</i><br /><br />A transmission line with potential application to terahertz ICs has been fabricated and characterized. The transmission line is a coaxial (shielded) line which is integrable and compatible with existing monolithic microwave integrated circuit (MMIC) technology. The structure is composed of a center conductor surrounded by a homogeneous dielectric (probimide), covered entirely by a gold plated ground plane. The coaxial lines are terminated to coplanar waveguide pads for on-wafer microwave measurements. The loss and other lumped transmission line parameters were extracted from the measured S-parameter data. The simulation results based on initial experimental data suggest the usefulness of coaxial line in the frequency range above 200 GHz. The shielded coaxial lines have the following characteristics: no radiation losses, no crosstalk between adjacent lines which enables denser IC design, compatible with existing MMIC technology, and easy transition to microstrip and coplanar waveguides Monolithic coaxial transmission lines for mm-wave ICs JA Bishop MM Hashemi K Kiziloglu L Larson N Dagli U Mishra High Speed Semiconductor Devices and Circuits, 1991., Proceedings IEEE/Cornell Conference on Advanced Concepts in (1991), pp. 252-260. 2007-05-14T09:02:31-00:00 1991 High Speed Semiconductor Devices and Circuits, 1991., Proceedings IEEE/Cornell Conference on Advanced Concepts in 252 260 mems rf waveguide http://www.citeulike.org/user/msterner/article/1295199 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 49, No. 9. (2001), pp. 1634-1639.</i><br /><br />In this paper, a new micromachined overlay-coplanar-waveguide (OCPW) structure has been developed and its characteristics are studied in detail as a function of the line parameters. In OCPW, the edges of the center conductors are lifted by micromachining techniques and partially overlapped with the ground plane to facilitate low-impedance lines. The elevated center conductors help to reduce the conductor loss by redistributing the current over a broad area. Comparative experiments on low-loss and lossy substrates also confirm the screening effect from the substrate losses by confining the electric field in the air between the overlapped conductor plates. Compared with the coplanar-waveguide (CPW) lines, the OCPW lines show wider impedance range (25-80 Ω) and lower loss (<0.95 dB/cm at 50 GHz). The advantages of OCPW for low-Z₀ lines are utilized to realize a high-performance stepped-impedance low-pass filter at X-band. The OCPW filter shows distinct advantages over the conventional CPW filter in terms of size, loss, skirt, and stopband characteristics A new micromachined overlay CPW structure with low attenuation over wide impedance ranges and its application to low-pass filters Hong-Teuk Kim Sanghwa Jung Jae-Hyoung Park Chang-Wook Baek Yong-Kweon Kim Youngwoo Kwon Microwave Theory and Techniques, IEEE Transactions on, Vol. 49, No. 9. (2001), pp. 1634-1639. 2007-05-14T14:31:22-00:00 2001 Microwave Theory and Techniques, IEEE Transactions on 49 9 1634 1639 mems rf waveguide http://www.citeulike.org/user/msterner/article/1294609 <i>Microwave and Optical Technology Letters, Vol. 40, No. 1. (2004), pp. 6-9.</i><br /><br />In this paper, we describe a new GaAs-based micromachined microstrip line, supported by an electrically supported air-gapped microstrip line (DAML) structure and developed using RF MEMS techniques to achieve low losses at millimeter-wave frequency bands with wide impedance ranges. The measured DAML with a 10-?m post height shows less than 1.5-dB/cm attenuation at 50 GHz with 20-100?, which agrees well with the simulated results. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 6-9, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11270 New micromachined microstrip transmission lines for application in millimeter-wave circuits Han-Shin Lee Sung-Chan Kim Byoung-Ok Lim Kyoung-Man Kim Won-Young Uhm Young-Hoon Chun Dong-Hoon Shin Soon-Koo Kim Hyun-Chang Park Jin-Koo Rhee doi:10.1002/mop.11270 Microwave and Optical Technology Letters, Vol. 40, No. 1. (2004), pp. 6-9. 2007-05-14T08:59:33-00:00 2004 Microwave and Optical Technology Letters 40 1 6 9 mems rf waveguide http://www.citeulike.org/user/msterner/article/1295100 <i>Electronics Letters, Vol. 39, No. 25. (2003), pp. 1827-1828.</i><br /><br />A new GaAs-based surface micromachined microstrip line Design and characterisation of micromachined transmission HS Lee DH Shin YH Chun SC Kim BO Lim TJ Baek SK Kim HC Park JK Rhee Electronics Letters, Vol. 39, No. 25. (2003), pp. 1827-1828. 2007-05-14T13:58:30-00:00 2003 Electronics Letters 39 25 1827 1828 mems rf waveguide http://www.citeulike.org/user/msterner/article/1294818 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 45, No. 5. (1997), pp. 630-635.</i><br /><br />Coplanar waveguides were designed and fabricated through a commercial CMOS process with post-processing micromachining. The transmission-line layouts were designed with commercial computer-aided design (CAD) tools. Integrated circuits (ICs) were fabricated through the MOSIS service, and subsequently suspended by top-side etching. The absence of the lossy silicon substrate after etching results in significantly improved insertion-loss characteristics, dispersion characteristics, and phase velocity. Two types of layout are presented for different ranges of characteristic impedance. Measurements of the waveguides both before and after micromachining were performed at frequencies from 1 to 40 GHz using a vector network analyzer and de-embedding techniques, showing improvement of loss characteristics of orders of magnitude. For the entire range of frequencies, for the 50-Ω layout, losses do not exceed 4 dB/cm. These losses are mainly due to the small width and thickness of the metal strips. Before etching, losses are as high as 38 dB/cm due to currents in the underlying substrate. Phase velocity in the micromachined transmission lines is close to that in free space Micromachined microwave transmission lines in CMOS technology V Milanovic M Gaitan ED Bowen ME Zaghloul Microwave Theory and Techniques, IEEE Transactions on, Vol. 45, No. 5. (1997), pp. 630-635. 2007-05-14T10:59:10-00:00 1997 Microwave Theory and Techniques, IEEE Transactions on 45 5 630 635 mems rf waveguide http://www.citeulike.org/user/msterner/article/1727925 <i>Silicon Monolithic Integrated Circuits in RF Systems, 2004. Digest of Papers. 2004 Topical Meeting on (2004), pp. 151-154.</i><br /><br />The paper illustrates the activity carried out under an ESA contract for the development of a miniaturized RF-MEMS SPDT switch and switch matrix using micromachining technology on a silicon substrate for power applications. A manufacturing procedure, based on an eight masks process, has been set up. At present, a broadband single-pole-double-throw (SPDT) switch operating in the 0-30 GHz frequency range has been fabricated and measured. Isolation of about -40 dB and insertion loss better than -0.7 dB have been obtained. RF-MEMS SPDT switch on silicon substrate for space applications P Farinelli F Giacomozzi G Mannocchi R Marcelli B Margesin P Mezzanotte S Di Nardo P Russer R Sorrentino F Vitulli L Vietzorreck Silicon Monolithic Integrated Circuits in RF Systems, 2004. Digest of Papers. 2004 Topical Meeting on (2004), pp. 151-154. 2007-10-04T16:44:56-00:00 2004 Silicon Monolithic Integrated Circuits in RF Systems, 2004. Digest of Papers. 2004 Topical Meeting on 151 154 mems rf spdt switch http://www.citeulike.org/user/msterner/article/1295552 <i>International Journal of RF and Microwave Computer-Aided Engineering, Vol. 9, No. 4. (1999), pp. 348-361.</i><br /><br />This paper reports on the development of a broadband, low insertion loss, ohmic-contact MEMs switch for microwave and millimeter-wave applications. The switch is surface-micromachined and electrostatically-actuated with electromechanical performance simulated with analytical and numerical models that compare well to experiment. The switch has an actuation voltage of 30 V, a response time of 20 ?s, and mechanical strength to withstand 109 actuations. A 3D electromagnetics scattering model developed iteratively with the electromechanical modeling predicts RF performance demonstrated to be greater than 50 dB of isolation below 2 GHz and less than 0.2 dB of insertion loss from DC through 40 GHz.   ©1999 John Wiley & Sons, Inc. Int J RF and Microwave CAE 9: 348-361, 1999. Surface-micromachined RF MEMs switches on GaAs substrates Daniel Hyman Juan Lam Brett Warneke Adele Schmitz TY Hsu Julia Brown James Schaffner Andy Walston Robert Loo Mehran Mehregany Jae Lee doi:10.1002/(SICI)1099-047X(199907)9:4<348::AID-MMCE6>3.0.CO;2-K International Journal of RF and Microwave Computer-Aided Engineering, Vol. 9, No. 4. (1999), pp. 348-361. 2007-05-14T16:53:14-00:00 1999 International Journal of RF and Microwave Computer-Aided Engineering 9 4 348 361 mems rf switch http://www.citeulike.org/user/msterner/article/1294810 <i>Components and Packaging Technologies, IEEE Transactions on [see also Components, Packaging and Manufacturing Technology, Part A: Packaging Technologies, IEEE Transactions on], Vol. 25, No. 3. (2002), pp. 506-510.</i><br /><br />We present the design and development of an ultra-violet (UV) LIGA (a German acronym for electroplating, lithography and molding) micromachining process on silicon substrates at microwave/millimeter wave frequencies. The process employs an ultra-thick negative photoresist SU-8 that can be spin-coated and processed using conventional lithography techniques. Using this process, we have developed micromachined coplanar waveguide (CPW) interconnects on Si substrates. The conductor-backed micromachined CPW on Si (7.2 /spl Omega/-cm) achieves a measured attenuation of 0.18 dB/cm at 20 GHz. Development of low loss organic-micromachined interconnects on silicon at microwave frequencies DP Newlin AVH Pham JE Harriss Components and Packaging Technologies, IEEE Transactions on [see also Components, Packaging and Manufacturing Technology, Part A: Packaging Technologies, IEEE Transactions on], Vol. 25, No. 3. (2002), pp. 506-510. 2007-05-14T10:51:54-00:00 2002 Components and Packaging Technologies, IEEE Transactions on [see also Components, Packaging and Manufacturing Technology, Part A: Packaging Technologies, IEEE Transactions on] 25 3 506 510 mems rf waveguide http://www.citeulike.org/user/msterner/article/1294591 <i>Microwave Symposium Digest., 2000 IEEE MTT-S International, Vol. 2 (2000), pp. 1225-1228 vol.2.</i><br /><br />A scheme for employing organic materials for micromachining of the packaging structure of membrane-supported millimeter wave circuits is described. The format of the packaging follows that devised by Brown, Blondy, and Rebeiz [1999]. The organic micromachining process employs bulk parts patterned photolithographically from Epon(R) SU-8 photoresist adhered to polyimide membranes. Conducting elements are formed by evaporation of gold, followed by electroplating for thickness build up Membrane-supported Ka band resonator employing organic micromachined packaging JE Harriss LW Pearson X Wang CH Barren AV Pham Microwave Symposium Digest., 2000 IEEE MTT-S International, Vol. 2 (2000), pp. 1225-1228 vol.2. 2007-05-14T08:41:06-00:00 2000 Microwave Symposium Digest., 2000 IEEE MTT-S International 2 1225 1228 vol.2 mems rf waveguide http://www.citeulike.org/user/msterner/article/1294586 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 46, No. 12. (1998), pp. 2283-2288.</i><br /><br />High-performance planar micromachined filters at 37 and 60 GHz are presented. The filters consist of a 3.5% bandwidth two-pole Chebyshev filter with transmission zeros at 37 GHz, 2.7% and 4.3% bandwidth four- and five-pole Chebyshev filters at 60 GHz, and an 8% bandwidth elliptic filter at 60 GHz. Silicon micromachining techniques combined with micropackaging have been applied to allow for very high-Q resonators resulting in low-loss filters. The 37-GHz two-pole filter exhibits a 2.3-dB port-to-port insertion loss. The 2.7% and 4.3% four- and five-pole Chebyshev filters at 60 GHz exhibit 2.8- and 3.4-dB insertion loss, and the 8% elliptic filter exhibits a 1.5-dB insertion loss. These values show a large reduction of insertion loss compared to conventional planar techniques, and can be used for planar low-cost millimeter-wave wireless communication systems Low-loss micromachined filters for millimeter-wave communication systems P Blondy AR Brown D Cros GM Rebeiz Microwave Theory and Techniques, IEEE Transactions on, Vol. 46, No. 12. (1998), pp. 2283-2288. 2007-05-14T08:37:11-00:00 1998 Microwave Theory and Techniques, IEEE Transactions on 46 12 2283 2288 mems rf waveguide http://www.citeulike.org/user/maxp/article/812897 <i>(2000), pp. 775-784.</i><br /><br />The proliferation of mobile computing devices and local-area wireless networks has fostered a growing interest in location-aware systems and services. In this paper we present RADAR, a radio-frequency (RF) based system for locating and tracking users inside buildings. RADAR operates by recording and processing signal strength information at multiple base stations positioned to provide overlapping coverage in the area of interest. It combines empirical measurements with signal propagation... RADAR: An In-Building RF-Based User Location and Tracking System Paramvir Bahl Venkata Padmanabhan (2000), pp. 775-784. 2006-08-22T17:57:09-00:00 2000 775 784 localization location rf tracking http://www.citeulike.org/user/maxp/article/423605 <i>(2004), pp. 190-202.</i> Tracking moving devices with the cricket location system Adam Smith Hari Balakrishnan Michel Goraczko Nissanka Priyantha doi:10.1145/990064.990088 (2004), pp. 190-202. 2005-12-06T20:06:47-00:00 2004 190 202 ACM Press indoor localization location rf ultrasound http://www.citeulike.org/user/maxp/article/275098 <i>(2000), pp. 32-43.</i> The Cricket location-support system Nissanka Priyantha Anit Chakraborty Hari Balakrishnan doi:10.1145/345910.345917 (2000), pp. 32-43. 2005-08-05T13:54:54-00:00 2000 32 43 ACM Press localization location rf ultrasound http://www.citeulike.org/user/maxp/article/1939550 <i>(2003)</i><br /><br />The Cricket indoor location project has been active for four years. We have developed three different versions of the system. The first version was an early proofof -concept (Cricket v0), which led to the first prototype (Cricket v1). Cricket v1 has seen extensive use by us and by a few other research groups in the community. During this time, we have learned a number of lessons from application designers, users, and system maintainers. We break these lessons into platform flexibility, where we ... Lessons from developing and deploying the Cricket indoor location system H Balakrishnan R Baliga D Curtis M Goraczko A Miu N Priyantha A Smith K Steele S Teller K Wang (2003) 2007-11-19T21:22:57-00:00 2003 indoor localization location rf ultrasound http://www.citeulike.org/user/maxp/article/1237491 <i>(2000)</i><br /><br />We address the problem of locating users inside buildings using a radio-frequency (RF) wireless LAN. A previous paper presented the basic design and a limited evaluation of a user-location system we have developed. In this paper, we analyze shortcomings of the basic system, and develop and evaluate solutions to address these shortcomings. Additionally, we describe several new enhancements, including a novel access point-based environmental profiling scheme, and a Viterbi-like algorithm for... Enhancements to the RADAR User Location and Tracking System P Bahl A Balachandran V Padmanabhan (2000) 2007-04-19T18:58:17-00:00 2000 fingerprint indoor localization location rf rss signal strength wifi wlan http://www.citeulike.org/user/maxp/article/5787 <i>Wireless Networks, Vol. 10, No. 6., 701.</i> LANDMARC: Indoor Location Sensing Using Active RFID: Pervasive Computing and Communications (Guest Editors: Mohan Kumar, Diane Cook and Anand Tripathi) Lionel Ni Yunhao Liu Yiu Lau Abhishek Patil doi:10.1023/B:WINE.0000044029.06344.dd Wireless Networks, Vol. 10, No. 6., 701. 2004-12-28T15:30:32-00:00 Wireless Networks 1022-0038 10 6 701 Kluwer Academic Publishers indoor location network rf rfid signal strength http://www.citeulike.org/user/masaakif/article/2392986 <i>IEEE Transactions on Circuits and Systems for Video Technology, Vol. 18, No. 1. (January 2008), pp. 3-11.</i><br /><br />With many potential industrial applications, content-based image retrieval (CBIR) has recently gained more attention for image management and web searching. As an important tool to capture users' preferences and thus to improve the performance of CBIR systems, a variety of relevance feedback (RF) schemes have been developed in recent years. One key issue in RF is: which features (or feature dimensions) can benefit this human-computer iteration procedure? In this paper, we make theoretical and practical comparisons between principal and complement components of image features in CBIR RF. Most of the previous RF approaches treat the positive and negative feedbacks equivalently although this assumption is not appropriate since the two groups of training feedbacks have very different properties. That is, all positive feedbacks share a homogeneous concept while negative feedbacks do not. We explore solutions to this important problem by proposing an orthogonal complement component analysis. Experimental results are reported on a real-world image collection to demonstrate that the proposed complement components method consistently outperforms the conventional principal components method in both linear and kernel spaces when users want to retrieve images with a homogeneous concept. Which Components are Important for Interactive Image Searching? Dacheng Tao Xiaoou Tang Xuelong Li doi:10.1109/TCSVT.2007.906936 IEEE Transactions on Circuits and Systems for Video Technology, Vol. 18, No. 1. (January 2008), pp. 3-11. 2008-02-18T08:50:11-00:00 2008 IEEE Transactions on Circuits and Systems for Video Technology 18 1 3 11 analysis based cbir complement component content content-based feedback image kernel machine occa orthogonal relevance retrieval rf support svm vector http://www.citeulike.org/user/martinthesis/article/1152838 <i>Progress in Particle and Nuclear Physics, Vol. 49, No. 1. (2002), pp. 155-244.</i><br /><br />The basics of superconductivity are outlined with special emphasis on the features which are relevant for the application in magnets and radio frequency cavities for high energy particle accelerators. The special properties of superconducting accelerator magnets are described in detail: design principles, magnetic field calculations, magnetic forces, quench performance and persistent magnetization currents. The design principles and basic properties of superconducting cavities are explained as well as the observed performance limitations and the countermeasures. The ongoing research efforts towards maximum accelerating fields are addressed and the coupling of radio frequency power to the particle beam is treated. Superconductivity in high energy particle accelerators P Schmuser doi:10.1016/S0146-6410(02)00145-X Progress in Particle and Nuclear Physics, Vol. 49, No. 1. (2002), pp. 155-244. 2007-03-10T13:17:22-00:00 2002 Progress in Particle and Nuclear Physics 49 1 155 244 cavity rf superconductivity http://www.citeulike.org/user/lutful/article/1207772 <i></i><br /><br />A plugin module for terrain analysis including radio link calculations has been constructed for a map presentation program (currently referred to as UniMap). The module contains tools for radio link calculations, terrain information, target sight, free sight boundary and sight field. It is implemented as a DLL using the COM programming model. All of the programming was done in C++ using the MFC (Microsoft Foundation Classes) library and Microsoft Visual Studio (Visual C++) as programming... Terrain Analysis with Radio Link Calculations for a Map Presentation Program Oskar Wibling 2007-04-05T06:28:41-00:00 foliage rf http://www.citeulike.org/user/longone/article/771077 <i>(17 Apr 2002)</i><br /><br />We present a technique to directly excite Luttinger liquid collective modes in carbon nanotubes at GHz frequencies. By modeling the nanotube as a nano-transmission line with distributed kinetic and magnetic inductance as well as distributed quantum and electrostatic capacitance, we calculate the complex, frequency dependent impedance for a variety of measurement geometries. Exciting voltage waves on the nano-transmission line is equivalent to directly exciting the yet-to-be observed one dimensional plasmons, the low energy excitation of a Luttinger liquid. Our technique has already been applied to 2d plasmons and should work well for 1d plasmons. Tubes of length 100 microns must be grown for GHz resonance frequencies. Ohmic contact is not necessary with our technique; capacitive contacts can work. A technique to directly excite Luttinger liquid collective modes in carbon nanotubes at GHz frequencies PJ Burke (17 Apr 2002) 2006-07-24T12:07:23-00:00 2002 carbon ghz liquid luttinger nanotube rf http://www.citeulike.org/user/laistler/article/1453384 <i>Microsystem Technologies, Vol. 13, No. 11-12. (July 2007), pp. 1575-1580.</i> Characterization of flexible RF microcoils dedicated to local MRI M Woytasik JC Ginefri JS Raynaud M Poirier-Quinot E Dufour-Gergam JP Grandchamp O Girard P Robert JP Gilles E Martincic L Darrasse doi:10.1007/s00542-006-0277-x Microsystem Technologies, Vol. 13, No. 11-12. (July 2007), pp. 1575-1580. 2007-07-13T07:02:59-00:00 2007 Microsystem Technologies 0946-7076 13 11-12 1575 1580 Springer coil microscopy mr rf http://www.citeulike.org/user/laistler/article/2963593 <i>Review of Scientific Instruments, Vol. 68, No. 5. (1997), pp. 1995-1997.</i><br /><br />A split-conductor parallel-plate transmission line resonator is a simple structure made from bending a strip of double-face copper-clad printed-circuit board into a loop with alternate electrical discontinuities (gaps) on opposite sides. Its natural resonant frequency (Fn) is determined by the transmission line characteristic impedance, the loop diameter or strip length, and the number (Ng) of gaps. It is easy to design high frequency resonators simply by increasing Ng. We propose here a single-gap multiturn resonator for low frequency operation as well as a simplified expression for the determination of Fn. A design procedure of this type of resonator is outlined and illustrative examples with parallel-plate as well as ordinary 50 Omega coaxial transmission lines are given. Also, for a given cable length, numerical calculation shows that the minimum resonator frequency can be attained with a form factor of the order of 2. ©1997 American Institute of Physics. Multiturn split-conductor transmission-line resonator Nathalie Haziza Jacques Bittoun Siew Kan Review of Scientific Instruments, Vol. 68, No. 5. (1997), pp. 1995-1997. 2008-07-04T10:21:51-00:00 1997 Review of Scientific Instruments 68 5 1995 1997 AIP coil mstr rf http://www.citeulike.org/user/jsydc/article/569118 <i>Magn Reson Med, Vol. 55, No. 4. (April 2006), pp. 865-873.</i><br /><br />Bandwidth-modulated selective saturation and inversion (BASSI) pulses are a class of frequency- and gradient-modulated radiofrequency (RF) pulses, derived from the hyperbolic secant pulse by temporal variation of the bandwidth parameter. These pulses afford optimal amplitude modulation, achieving uniform and highly selective profiles at any effective flip angle. In this paper, BASSI pulses are parameterized to obtain low RF energy pulsed arterial spin labeling (PASL) label pulses with minimal contamination of static spins outside the label region and highly selective PICORE/QUIPSS II saturation pulses allowing for small label gaps. They are compared to frequency offset corrected inversion (FOCI) label pulses and sinc saturation pulses in simulations and a phantom experiment. Drawing on the outstanding selectivity of bandwidth-modulated saturation pulses, a new noninvasive method to measure in vivo the contamination effects due to direct and indirect saturation of static spins by the label pulse is presented. In an in vivo study on four subjects, contamination effects in a QUIPSS II PASL implementation based on BASSI pulses are compared to those present in a state-of-the-art Q2TIPS sequence employing a FOCI label pulse. Residual contamination in the QUIPSS II/BASSI sequence is shown to be reduced by a factor of 3, compared to the Q2TIPS/FOCI sequence. In vivo human perfusion images obtained with a label gap of only 2 mm are presented. Magn Reson Med, 2006. (c) 2006 Wiley-Liss, Inc. Reducing contamination while closing the gap: BASSI RF pulses in PASL. JM Warnking GB Pike doi:10.1002/mrm.20843 Magn Reson Med, Vol. 55, No. 4. (April 2006), pp. 865-873. 2006-03-30T01:52:23-00:00 2006 Magn Reson Med 0740-3194 55 4 865 873 pulse rf http://www.citeulike.org/user/jkominek/article/257573 <i>INFOCOM 2000. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies. Proceedings. IEEE, Vol. 2 (2000), pp. 775-784 vol.2.</i><br /><br />The proliferation of mobile computing devices and local-area wireless networks has fostered a growing interest in location-aware systems and services. In this paper we present RADAR, a radio-frequency (RF)-based system for locating and tracking users inside buildings. RADAR operates by recording and processing signal strength information at multiple base stations positioned to provide overlapping coverage in the area of interest. It combines empirical measurements with signal propagation modeling to determine user location and thereby enable location-aware services and applications. We present experimental results that demonstrate the ability of RADAR to estimate user location with a high degree of accuracy RADAR: an in-building RF-based user location and tracking system P Bahl VN Padmanabhan INFOCOM 2000. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies. Proceedings. IEEE, Vol. 2 (2000), pp. 775-784 vol.2. 2005-07-16T07:32:08-00:00 2000 INFOCOM 2000. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies. Proceedings. IEEE 2 775 784 vol.2 location navigation rf tracking wifi