Compact Ultra Wide Band Sinuous Antenna

Compact Antenna Test Facility (CATF) facility is extensively used for evaluating the antenna pattern and payload performance for all communication satellites in the integrated condition. Operating frequency range of the CATF is from 1-40 GHz. Standard feeds are available in CATF, which will cater testing in the frequency range from 1 - 40 GHz. Facility can also be used as standard far-field range (By-passing the reflectors and in direct Line Of Sight: LOS) for limited characterization of antennas in the frequency range less than 1GHz. With an increase in the application of UHF frequency usage in the spacecraft sphere, it is required to extend feed capability in the lower operating frequency range of facility. In view of this, it was proposed to design and develop an UWB antenna operating in the frequency band from 200 MHz - 1 GHz so that facility measurement capabilities can be extended. In this paper, design aspects of antenna, feeding network, fabrication, pattern and gain measurement procedure are discussed. Comparison of simulated & measured pattern and gain values shows good match between them.