An Innovative Portable Ultra Wide Band Stereophonic Radio Direction Finder

Abstract

Abstract-A portable ultra wide band radio direction finder has been constructed based on the principle of stereophonic direction recognition of sound by human ears. The instrument consists of two log periodic antennas having identical electrical properties. They are positioned in a plane, preferably parallel to the ground. The directivities of the antennas are aligned at slightly different directions with respect to each other. Their output powers are compared at the source frequency for the respective polarizations. The back lobes of the antennas have been reduced by symmetrically positioning two metallic plates (reflectors) behind the antennas. The antennas, reflectors and a compass are mounted over a video camera stand such that they could be manually positioned in the azimuth. Since the antennas are of identical make, ideally the radiation pattern of either antennareflector combination should behave as a flipped image of the other set. For any particular polarization and frequency, the outputs from the antennas are compared with each other. The antenna assembly is rotated between 0 and 360 • in the azimuth until the power difference gets minimized. This position relates to the direction of the source and is indicated on the compass, provided there exits a single radio source at that frequency.

Synthesis ofn-way active topology for wide-band RF/microwave applications

“…In this optic, different extensions of the popular Wilkinson power-splitter were proposed in *Email: blaise.ravelo@yahoo.fr ISSN 0020-7217 print/ISSN 1362-3060 online ß 2012 Taylor & Francis http://dx.doi.org/10.1080/00207217.2011.643488 http://www.tandfonline.com the literature. But mostly, with classical passive devices which are regularly used in RF/microwave systems, the insertion loss unavoidably increases with the way number of the power combiners (Simons and Ponchak 1990;Eccleston 2006;Chen and Zhang 2007;Joardar, Jaint, Bandewar, and Bhattacharya 2008;Hubbard and Ordy 2009;Chen, Wang, Shi, Zhang, and Tong 2010;Wu, Liu, Li, Yu, and Liu 2010;16 Way). In this scope, we have the same effects for the another family of n-way devices generally used for the transformation of balanced to unbalanced signals which are frequently found for the microwave applications and also for the near-field measurement test bench (Baudry, Louis, and Mazari 2006).…”

An Equivalent Circuit Modeling Method for Ultra-Wideband Antennas

“…Although the large bandwidth enables short-range, high data-rate communication and high resolution positioning [4], it imposes new design challenges in UWB systems [23,24]. One challenge is the co-design of UWB antenna/circuit interface.…”