Title :
Measured RF characteristics of a TEM-wire fed reflector
Author :
King, H.E. ; Wong, J.L.
Abstract :
The RF characteristics of a parabolic reflector antenna illuminated with a transverse-electromagnetic (TEM)-wire feed are described. The reflector operates in the frequency range of 150 to 3750 MHz (25:1 bandwidth) and has a diameter of 48 in. (0.61 lambda at the lowest operating frequency). The TEM-wire feed is formed by spreading out the wires of a two-wire transmission line. The length of the individual wires was fixed at 20 in. ( approximately lambda /4 at 150 MHz) and the wires were arranged in an exponentially flared configuration. Measured RF characteristics including voltage standing wave ratio (VSWR), gain, directivity, patterns, and axial ratio for an e/sup x/ feed configuration are presented. The VSWR characteristics are cyclic with frequency. The reflector´s half-power beamwidth and directivity vs. frequency curves generally have the same slope as a conventional reflector antenna.<>
Keywords :
antenna feeders; antenna radiation patterns; reflector antennas; 150 to 3750 MHz; RF characteristics; SHF; TEM-wire fed reflector; UHF; VHF; VSWR; axial ratio; directivity; gain; microwave antenna; parabolic reflector antenna; patterns; voltage standing wave ratio; Antenna feeds; Antenna measurements; Bandwidth; Gain measurement; Loss measurement; Polarization; Radio frequency; Reflector antennas; Transmission line measurements; Wire;
Conference_Titel :
Antennas and Propagation Society International Symposium, 1990. AP-S. Merging Technologies for the 90's. Digest.
Conference_Location :
Dallas, TX, USA
DOI :
10.1109/APS.1990.115098
