CiteULike: dcastro's measurement http://www.citeulike.org/user/dcastro/tag/measurement CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dcastro/article/2802347 <i>Ultra Wideband Systems, 2004. Joint with Conference on Ultrawideband Systems and Technologies. Joint UWBST & IWUWBS. 2004 International Workshop on (2004), pp. 400-404.</i><br /><br />The paper reports on the development of a low-cost device for low data rate communications with tracking and positioning capabilities. We investigate the performance of two different position estimation methods based on the estimate of the time-of-arrival (TOA) of the UWB signal at a set of receivers/sensors. The performance evaluation is performed in terms of the root mean-squared (RMS) error of the position coordinates estimation and the failure rate. We first study the direct-calculation method which gives exact solutions of a set of simultaneous equations. We then study one of the classical nonlinear optimization techniques, the Davidon-Fletcher-Powell (DFP) quasi-Newton algorithm. Both the direct-calculation method and the nonlinear optimization algorithms do not require any knowledge of the TOA estimation error variance or distribution. This advantage would be attractive for practical applications. Performance of UWB position estimation based on time-of-arrival measurements Kegen Yu I Oppermann doi:10.1109/UWBST.2004.1321004 Ultra Wideband Systems, 2004. Joint with Conference on Ultrawideband Systems and Technologies. Joint UWBST & IWUWBS. 2004 International Workshop on (2004), pp. 400-404. 2008-05-15T18:37:42-00:00 Ultra Wideband Systems, 2004. Joint with Conference on Ultrawideband Systems and Technologies. Joint UWBST & IWUWBS. 2004 International Workshop on 400 404 estimation measurement position time uwb http://www.citeulike.org/user/dcastro/article/2801482 <i>Millimeter Waves, 1997 Topical Symposium on (1997), pp. 137-140.</i><br /><br />This paper presents FDTD simulation and measurement results for a microstrip-fed Yagi-Uda slot array antenna used for surface wave excitation of a dielectric slab. Parameters investigated are input return loss, surface wave field profiles, front-to-back ratio and mutual coupling. The FDTD simulation not only confirms the design philosophy of our planar dielectric quasi-optical (PDQ) power combiner, but also provides a powerful CAD tool for its practical design and optimization at millimeter wavelengths Surface wave excitation of a dielectric slab by a Yagi-Uda slot array antenna-FDTD simulation and measurement Yongxi Qian AR Perkons T Itoh doi:10.1109/TSMW.1997.702490 Millimeter Waves, 1997 Topical Symposium on (1997), pp. 137-140. 2008-05-15T12:21:01-00:00 Millimeter Waves, 1997 Topical Symposium on 137 140 array fdtd measurement simulation surface wave http://www.citeulike.org/user/dcastro/article/2782042 <i>Microwave Symposium Digest., 2000 IEEE MTT-S International, Vol. 1 (2000), pp. 593-596 vol.1.</i><br /><br />This paper describes the analysis, design, implementation and characterization of a computer-controlled system that accurately measures the phase and amplitude distributions of a phased antenna array. The proposed setup allows `on board' measurements and far field radiation pattern collection at the same time. We have measured the phase and amplitude distributions of a coupled oscillator array at 2.4-2.6 GHz. The results are coherent with the theoretical expectations. The amplitude error is less than 5% and the phase error is less than 5°. This simple and inexpensive measurement system can be used for automated diagnostics of linear and nonlinear antenna arrays Measurement of the phase and amplitude distributions of coupled oscillator arrays PF Maccarini TP Dao AS Nagra A Borgioli RA York doi:10.1109/MWSYM.2000.861137 Microwave Symposium Digest., 2000 IEEE MTT-S International, Vol. 1 (2000), pp. 593-596 vol.1. 2008-05-09T23:55:44-00:00 Microwave Symposium Digest., 2000 IEEE MTT-S International 1 593 596 vol.1 array measurement oscillator phase http://www.citeulike.org/user/dcastro/article/2782026 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 45, No. 5. (1997), pp. 580-586.</i><br /><br />A new method, using the noise matrix approach, has been developed for determining the optimum reactive terminations for a transistor employed as a low-noise negative-resistance element in a reflection-mode amplifier. This new method corroborates the less efficient graphical method the authors reported earlier. It is established theoretically and demonstrated numerically that the optimum noise measure of a transistor used in a reflection-mode amplifier is independent of the choice of active terminal and is identical to the optimum noise measure of the same transistor when used in a conventional transmission-mode amplifier Optimum noise measure configurations for transistor negative resistance amplifiers P Gardner DK Paul doi:10.1109/22.575572 Microwave Theory and Techniques, IEEE Transactions on, Vol. 45, No. 5. (1997), pp. 580-586. 2008-05-09T23:50:36-00:00 Microwave Theory and Techniques, IEEE Transactions on 45 5 580 586 amplifier measurement noise http://www.citeulike.org/user/dcastro/article/2770275 <i>Vehicular Technology Conference, 1983. 33rd IEEE, Vol. 33 (1983), pp. 265-268.</i> Propagation measurements for land mobile satellite services RW Huck JS Butterworth EE Matt Vehicular Technology Conference, 1983. 33rd IEEE, Vol. 33 (1983), pp. 265-268. 2008-05-08T08:58:47-00:00 Vehicular Technology Conference, 1983. 33rd IEEE 33 265 268 measurement mobile propagation satellite http://www.citeulike.org/user/dcastro/article/2762104 <i>Microwave Symposium Digest, 1994., IEEE MTT-S International (1994), pp. 1473-1476 vol.3.</i><br /><br />A novel technique is proposed for the measurements of the transducer power gain and noise figure of the amplifier embedded in a receiving active antenna, where the direct measurements with traditional techniques are impossible. The bandwidth of the active antenna can be also determined with this technique. The good agreement between the measurements and calculations of a number of active receiving microstrip antennas shows the validity of the measurement technique. This makes it possible to characterize all the performance of receiving active antennas A novel measurement technique for amplifier-type active antennas H An BKJC Nauwelaers AR Van de Capelle RG Bosisio doi:10.1109/MWSYM.1994.335133 Microwave Symposium Digest, 1994., IEEE MTT-S International (1994), pp. 1473-1476 vol.3. 2008-05-06T17:19:23-00:00 Microwave Symposium Digest, 1994., IEEE MTT-S International 1473 1476 vol.3 active amplifier antenna measurement http://www.citeulike.org/user/dcastro/article/2762100 <i>Electronics Letters, Vol. 29, No. 18. (1993), pp. 1594-1596.</i><br /><br />A novel technique for the measurement of the noise figure is proposed for an amplifier embedded in a receiving active microstrip antenna, where direct measurement is impossible. The proposed technique is a combination of the transducer power gain measurement of the amplifier and the absolute noise power measurement of the active antenna. The measured results of a receiving active microstrip antenna show the validity of the measurement technique. This enables the characterisation of the noise performance of active antennas Noise figure measurement of receiving active microstrip antennas H An B Nauwelaers A Van de Capelle Electronics Letters, Vol. 29, No. 18. (1993), pp. 1594-1596. 2008-05-06T17:19:01-00:00 Electronics Letters 29 18 1594 1596 active antenna measurement microstrip noise receiving http://www.citeulike.org/user/dcastro/article/2648094 <i>Vehicular Technology, IEEE Transactions on, Vol. 39, No. 2. (1990), pp. 132-139.</i><br /><br />The results of multipath power delay profile measurements of 900-MHz mobile radio channels in Washington, DC, Greenbelt, MD, Oakland, CA, and San Francisco, CA, are presented. The measurements have focused on acquiring worst-case profiles for typical operating locations. The data reveal that at over 98% of the measured locations, root mean square (RMS) delay spreads are less than 12 μs. Urban areas typically have RMS delay spreads on the order of 2-3 μs and continuous multipath power out to excess delays of 5 μs. In hilly residential areas and in open areas within a city, RMS delay spreads are slightly larger, typically having values of 5-7 μs. In very rare instances, reflections from city skylines and mountains can cause RMS delay spreads in excess of 20 μs. The worst-case profiles show resolvable diffuse multipath components at excess delays of 100 μs and amplitudes 18 dB below that of the first arriving signal 900-MHz multipath propagation measurements for US digital cellular radiotelephone TS Rappaport SY Seidel R Singh doi:10.1109/25.54229 Vehicular Technology, IEEE Transactions on, Vol. 39, No. 2. (1990), pp. 132-139. 2008-04-10T06:20:47-00:00 Vehicular Technology, IEEE Transactions on 39 2 132 139 digital measurement mobile multipath propagation http://www.citeulike.org/user/dcastro/article/2362131 <i>Proceedings of the IEEE, Vol. 87, No. 1. (1999), pp. 48-64.</i><br /><br />Although originally developed for the military, the Global Positioning System (GPS) has proven invaluable for a multitude of civilian applications. Each application demands specific performance from the GPS receiver and the associated requirements often vary widely. This paper describes the architectures and functions of civilian GPS receivers and then focuses on performance considerations. The fundamental receiver measurements are described and the quality of these measurements are related to the aforementioned receiver architectures GPS receiver architectures and measurements MS Braasch AJ van Dierendonck doi:10.1109/5.736341 Proceedings of the IEEE, Vol. 87, No. 1. (1999), pp. 48-64. 2008-02-11T09:58:35-00:00 Proceedings of the IEEE 87 1 48 64 delay dll gnss gps loop measurement receiver http://www.citeulike.org/user/dcastro/article/2072403 <i>Vehicular Technology, IEEE Transactions on, Vol. 46, No. 3. (1997), pp. 537-543.</i><br /><br />This paper presents antenna-gain measurements of handheld terminals by the random-field measurement (RFM) method. We have measured the relative antenna gain for different-sized terminal boxes in indoor and outdoor environments to show a gain decrease caused by the box size. The measured results are explained by calculating the average gain of the horizontal radiation pattern. To find the effect by a different human carrier, we also measured the antenna gain for several parameters, such as weight, height, head parameters, and the antenna protruding length from the head. We present a correlation factor of the antenna-gain deviation due to different human carriers Antenna-gain measurement of handheld terminals at 900 MHz H Arai N Igi H Hanaoka Vehicular Technology, IEEE Transactions on, Vol. 46, No. 3. (1997), pp. 537-543. 2007-12-07T10:13:04-00:00 Vehicular Technology, IEEE Transactions on 46 3 537 543 antenna gain measurement mobile http://www.citeulike.org/user/dcastro/article/1474537 <i>Communications Magazine, IEEE, Vol. 33, No. 1. (1995), pp. 42-49.</i><br /><br />The authors describe the type of signals that occur in various environments and the modeling of the propagation parameters. Models are essentially of two classes. The first class consists of parametric statistical models that on average describe the phenomenon within a given error. They are simple to use, but relatively coarse. In the last few years a second class of environment-specific models has been introduced. These models are of a more deterministic nature, characterizing a specific street, building, etc. They are necessarily more time consuming to use, but are also more revealing concerning physical details and hopefully more accurate. Some key parameters and the measurement of them are discussed and then the different wireless environments are treated. The latter topic is divided into outdoor environments, indoor environments, and radio penetration from outdoor to indoor environments Propagation measurements and models for wireless communications channels JB Andersen TS Rappaport S Yoshida Communications Magazine, IEEE, Vol. 33, No. 1. (1995), pp. 42-49. 2007-07-23T09:55:26-00:00 Communications Magazine, IEEE 33 1 42 49 channels communication measurement model propagation wireless http://www.citeulike.org/user/dcastro/article/1915032 <i>Antennas and Propagation Magazine, IEEE, Vol. 46, No. 1. (2004), pp. 59-64.</i><br /><br />A broadband spiral antenna (2 to 18 GHz) is modeled using the FDTD method. The inner turn of the antenna is an Archimedean spiral, while the outer turn is an Archimedean spiral with a zigzag shape. The current-density distribution along the spiral arms is first presented in the time domain, interestingly manifesting the impulse current propagation from the feed point to the outer end of the spiral arms. The performance of the broadband spiral antenna is also measured in an anechoic chamber. The simulated and measured results showed the sensitivity of the axial ratio and radiation pattern to the current distribution. The simulated linear gain, radiation patterns, and axial ratios agree well with the measured data over all of the frequency range from 2 to 18 GHz. Analysis and measurement of a broadband spiral antenna MN Afsar Yong Wang R Cheung Antennas and Propagation Magazine, IEEE, Vol. 46, No. 1. (2004), pp. 59-64. 2007-11-14T17:42:46-00:00 Antennas and Propagation Magazine, IEEE 46 1 59 64 antenna broadband measurement