A VHF Circularly Polarized Turnstile Antenna with Balun for Meteor Radar

This paper presents a circularly polarized turnstile antenna for meteor radar system. The employs pair of radiators, 1:2 power divider and 90° phase shifter. After series simulations optimizations, the maximum gain at 39 MHz is 5.9 dBic with 96° 3 dB beam width. simulated axial ratio below from −39° to 39° within band interest. Then, proposed fabricated applied Two tests are carried out radiation characteristics demonstration. In first test, VSWR 1.2 38.5–39.5 keeps good agreement simulation results. However, azimuth distribution illogical when output results compared Australian detection (ATRAD) detection. To address problem, baluns investigated introduced balanced feeding. 1:1 unbalance–balance transformer has been used improve designed antenna. final test show that system improved achieves better performances in counts distribution.