Sat, 26 Jul 2008 04:39:40 BST CiteULike: Tag transmitter http://www.citeulike.org/tag/transmitter CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/summerxia/article/423669 <i>Sensors and Actuators A: Physical, Vol. In Press, Corrected Proof</i><br /><br />AbsractThis paper describes the design of the complete transmit and receive electronics circuitry for a piezoelectric transducer in one single ASIC. The chip will be one building block in a thumb size battery operated ultrasound measurement system. The main design target has been to achieve extremely low power consumption while keeping the number of external components minimal.To overcome the dynamic range limitations imposed by a battery supply an on-chip boost converter uses one external inductor to generate up to 40 V for excitation of the transducer. The transducer itself is used as a storage capacitor, whereafter it is rapidly discharged to generate an ultrasound pulse. An on-chip amplifier with intermittent operation is controlled by a state machine and used to amplify incoming echoes. The chip has been fabricated in a 0.8 m high voltage CMOS process, with a total chip area of 12 mm2.Measurements verify the design approach. The power consumption for the system reaches within a factor of 2 of the power needed to charge the capacitance of the piezoelectric transducer from a fixed voltage source. The results show the possibility to achieve extremely low power consumption in a battery operated pulse-echo ultrasound measurement system. Ultra-low power transmit/receive ASIC for battery operated ultrasound measurement systems Jonny Johansson Martin Gustafsson Jerker Delsing doi:10.1016/j.sna.2005.08.029 Sensors and Actuators A: Physical, Vol. In Press, Corrected Proof 2005-12-06T21:59:20-00:00 Sensors and Actuators A: Physical In Press, Corrected Proof low-power transmitter http://www.citeulike.org/user/masaakif/article/2439443 <i>IEEE Transactions on Image Processing, Vol. 15, No. 12. (December 2006), pp. 3627-3635.</i><br /><br />In this paper, we propose a combined source/channel coding scheme for transmission of images over fading channels. The proposed scheme employs rate-compatible low-density parity-check codes along with embedded image coders such as JPEG2000 and set partitioning in hierarchical trees (SPIHT). The assignment of channel coding rates to source packets is performed by a fast trellis-based algorithm. We examine the performance of the proposed scheme over correlated and uncorrelated Rayleigh flat-fading channels with and without side information. Simulation results for the expected peak signal-to-noise ratio of reconstructed images, which are within 1 dB of the capacity upper bound over a wide range of channel signal-to-noise ratios, show considerable improvement compared to existing results under similar conditions. We also study the sensitivity of the proposed scheme in the presence of channel estimation error at the transmitter and demonstrate that under most conditions our scheme is more robust compared to existing schemes Progressive Transmission of Images Over Fading Channels Using Rate-Compatible LDPC Codes Xiang Pan Amir Banihashemi Aysegul Cuhadar doi:10.1109/TIP.2006.882030 IEEE Transactions on Image Processing, Vol. 15, No. 12. (December 2006), pp. 3627-3635. 2008-02-28T02:37:32-00:00 2006 IEEE Transactions on Image Processing 15 12 3627 3635 algorithm channel channels check coders codes coding combined communication embedded error estimation fading flat-fading image images joint ldpc low-density parity parity-check progressive protection rate-allocation rate-compatible rayleigh reconstruction scheme sourcechannel source-channel transmission transmitter trellis trellis-based unequal visual http://www.citeulike.org/user/hoverste/article/2754921 <i>Radio and Wireless Symposium, 2006 IEEE (2006), pp. 259-262.</i><br /><br />Digital predistortion linearization results are often degraded by nonideal factors in the transmitter chain. Among them, the gain ripple and phase delay of the analog reconstruction filter and the gain and phase imbalance of quadrature modulator are the major sources of linearizer performance degradation. The paper studies these effects and presents general guidelines for filter selection and imbalance compensation to maximize the predistortion performance. Nonideal effects of reconstruction filter and I/Q imbalance in digital predistortion MY Li JX Deng LE Larson PM Asbeck doi:10.1109/RWS.2006.1615144 Radio and Wireless Symposium, 2006 IEEE (2006), pp. 259-262. 2008-05-05T02:44:14-00:00 2006 Radio and Wireless Symposium, 2006 IEEE 259 262 asbeck dpd filter imbalance iq reconstruction transmitter http://www.citeulike.org/user/dcastro/article/2758012 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 53, No. 10. (2005), pp. 3206-3214.</i><br /><br />A novel fully integrated transmitter front-end with a simple structure is proposed to obtain both high power-added efficiency (PAE) and a compact RF-front structure. To have all these characteristics, a novel antenna operating as a radiator, a harmonic tuning circuit, and an output matching network of the power amplifier is proposed. Therefore, the direct integration of the output of the power amplifier and antenna can be achieved without any impedance transformers. From the measured results and fabrication, it is shown that the proposed transmitter front-end provides high PAE of 67.5% and compact and integrated RF-front structure by the size reduction of 43% compared with the conventional class-F active antenna for high PAE. A novel fully integrated transmitter front-end with high power-added efficiency Hyungrak Kim Ick-Jae Yoon Young Yoon doi:10.1109/TMTT.2005.855142 Microwave Theory and Techniques, IEEE Transactions on, Vol. 53, No. 10. (2005), pp. 3206-3214. 2008-05-05T14:11:58-00:00 2005 Microwave Theory and Techniques, IEEE Transactions on 53 10 3206 3214 antenna efficiency high integrated power transmitter http://www.citeulike.org/user/dcastro/article/2782041 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 50, No. 3. (2002), pp. 814-826.</i><br /><br />The generation of RF/microwave power is required not only in wireless communications, but also in applications such as jamming, imaging, RF heating, and miniature dc/dc converters. Each application has its own unique requirements for frequency, bandwidth, load, power, efficiency, linearity, and cost. RF power is generated by a wide variety of techniques, implementations, and active devices. Power amplifiers are incorporated into transmitters in a similarly wide variety of architectures, including linear, Kalm, envelope tracking, outphasing, and Doherty. Linearity can be improved through techniques such as feedback, feedforward, and predistortion Power amplifiers and transmitters for RF and microwave FH Raab P Asbeck S Cripps PB Kenington ZB Popovic N Pothecary JF Sevic NO Sokal doi:10.1109/22.989965 Microwave Theory and Techniques, IEEE Transactions on, Vol. 50, No. 3. (2002), pp. 814-826. 2008-05-09T23:54:52-00:00 2002 Microwave Theory and Techniques, IEEE Transactions on 50 3 814 826 amplifier microwave power rf transmitter http://www.citeulike.org/user/dcastro/article/2782037 <i>Microwave Magazine, IEEE, Vol. 1, No. 4. (2000), pp. 48-59.</i><br /><br />This article surveys recent progress in the development of high-power microwave and millimeter-wave solid-state sources using spatial power-combining techniques. Several promising topologies are discussed, and four technology demonstrations are presented that have emerged from recent research in academia and industry. We also include a brief discussion of potential applications and systems insertion issues Spatial power combining for high-power transmitters J Harvey ER Brown DB Rutledge RA York doi:10.1109/6668.893246 Microwave Magazine, IEEE, Vol. 1, No. 4. (2000), pp. 48-59. 2008-05-09T23:51:39-00:00 2000 Microwave Magazine, IEEE 1 4 48 59 power transmitter http://www.citeulike.org/user/dcastro/article/2774607 <i>Microwave Symposium Digest, 1998 IEEE MTT-S International, Vol. 2 (1998), pp. 455-458 vol.2.</i><br /><br />This paper describes a high efficiency amplifier that uses the load presented by a patch antenna to work in class “E”. The resulting set is a high efficiency transmitting active antenna. The dimensions, shape and location of the feeding point in the antenna are selected to obtain an input impedance to force the transistor to work in class “E” at 885 MHz with very high collector efficiency: ηc=90%@Vcc=12.5, Pout=1.5 W High efficiency mode “E” amplifier powers high efficiency active transmitting patch antenna Ortega Asensio Gonzalez Jimenez Martin doi:10.1109/MWSYM.1998.705031 Microwave Symposium Digest, 1998 IEEE MTT-S International, Vol. 2 (1998), pp. 455-458 vol.2. 2008-05-09T07:26:00-00:00 1998 Microwave Symposium Digest, 1998 IEEE MTT-S International 2 455 458 vol.2 active amplifier antenna efficiency high patch transmitter http://www.citeulike.org/user/dcastro/article/2782065 <i>Microwave Conference, 2000 Asia-Pacific (2000), pp. 888-894.</i><br /><br />In this paper, we present two novel design architectures that utilizing either a periodic structure or an active integrated antenna (AIA) for harmonic tuning in transmitter front-end designs. These techniques promise to significantly improve the power amplifier efficiency, reduce losses and weight, as well as maintaining good linearity requirements of advanced wireless communication systems. We will illustrate these two concepts through several design examples that have been developed recently, including a power amplifier integrated with novel PBG ground plane for harmonic tuning and four push-pull PA design examples, where the AIA concept is implemented to allow antenna to serve as a power combiner, a harmonic tuning load, in addition to its original functionality as a radiating element High efficiency transmitter front-ends integrated with planar antennas and PBG CY Hang WR Deal Yongxi Qian T Itoh doi:10.1109/APMC.2000.925972 Microwave Conference, 2000 Asia-Pacific (2000), pp. 888-894. 2008-05-10T00:03:23-00:00 2000 Microwave Conference, 2000 Asia-Pacific 888 894 antenna efficiency front-end high integrated pbg planar transmitter http://www.citeulike.org/user/dcastro/article/2762226 <i>Microwave Symposium Digest, 1998 IEEE MTT-S International, Vol. 1 (1998), pp. 327-330 vol.1.</i><br /><br />This paper presents several power amplifier approaches that promise to significantly improve efficiency, while meeting the linearity requirements of advanced, spectrally efficient wireless systems. The approaches include: a) use of active integrated antenna structures that provide harmonic terminations for high efficiency Class F amplifiers; b) integrated dc-dc converters for power conditioning and envelope restoration; c) switching mode amplifiers based on bipolar transistors with controlled saturation; and d) the use of band-pass delta-sigma modulators to tailor input signals Device and circuit approaches for improved linearity and efficiency in microwave transmitters PM Asbeck T Itoh Y Qian MF Chang L Milstein G Hanington PF Chen V Schultz DW Lee DW Lee J Arun A10 doi:10.1109/MWSYM.1998.689385 Microwave Symposium Digest, 1998 IEEE MTT-S International, Vol. 1 (1998), pp. 327-330 vol.1. 2008-05-06T18:30:58-00:00 1998 Microwave Symposium Digest, 1998 IEEE MTT-S International 1 327 330 vol.1 efficiency microwave transmitter