Global Positioning System (GPS) Pseudolite Transmit Antenna

ThinKom, with > 10 years experience developing lightweight, low-cost and high efficiency antennas (some with cosecant squared beam shaping) using Continuous Transverse Stub (CTS) antenna technology (and a license to CTS from Raytheon), and using two yearsof commercial antenna technology development, including an innovative antenna technology called WaveTrap offering wideband, beam shaping and beam steering capabilities, will investigate and recommend a GPS pseudolite transmit antenna technology and design.Recommended antennas will exhibit these features (like ThinKom's WaveTrap antenna technology): 1) total radiation efficiency > 70% (< 0.2dB ohmic loss between power amplifier and free space), 2) offer low (about 10 ohms) match to power amplifier (e.g. HPAor SSPA) to achieve high amplifier power added efficiency, 3) be physically low profile (< 1 inch thick), small (about 6 inches in diameter) and light weight (< 1 lb), 4) allow ease in shaping elevation beam (i.e. achieve cosecant squared beam shape withno physical impact), 5) provide ease in dynamically selecting azimuth coverage to maximize gain (& EIRP) over a desired ground area, 6) be of robust physical construction to withstand both airborne and ground vehicle environments, and 7) use low costcommercial materials and processes to achieve affordability. An antenna exhibiting all the features described in the technical abstract, plus supporting a wide operating bandwidth (which WaveTrap does), would also have many applications for mobile highdata rate communications, such as Mobile WLANs. When the operating bandwidth spans from 0.5 to 6 GHz (which WaveTrap does), then the antenna can support communication functions such as WLAN as well as other functions such as satellite based navigationusing GPS (and other low frequency satellite functions such as satellite telephony and radio). The automotive and telecommunication industries are seeking (together, for Telematics and separately for Mobile WLAN) multi-band and wideband, low profile, highefficiency (high data rate) antennas that support multiple functions.Mobile WLAN concepts are being pursued for commercial applications under the umbrella of Intelligent Transportation Systems (Department of Transportation sponsored investigations) as well as under the broader category of Telematics for cars, trucks, etc.In addition, the telecommunication industry, as part of the development of 3G and associated mobile wireless data communications, have been investigating how to seamlessly integrate mobile wireless networks (cellular and PCS networks) with the existing andgrowing number of WLAN (802.11 based)