A Synchronous Sub-Array Circularly Polarized Microstrip Antenna for Bisar Onboard Uav

Abstract

A circularly polarized microstrip antenna for bi-static SAR onboard UAV has been investigated. The both senseof the circular polarization left-hand circularly polarized (LHCP) and right-hand circularly polarized (RHCP) arecan be achieved on experimental and simulation. The 2x2 sub array antenna operated in 1.176 (L-band) withnovel proximity synchronous feed method has been designed, fabricated, and evaluated to show the characteristic of the antenna. The measured result give the axial ratio bandwidth (<3dB) of about 28 MHz (2%), whichconsistent with the simulated result of about 27 MHz (2%). These results satisfy the specification for our BiSARsystem installed onboard UAV.