Dual-Band Circularly Polarized Microstrip Planar Array Antenna with Inter-leaved Elements for Geo-stationary Satellite TT&C Application

Designing a dual-band circularly polarized planar array with good isolation between the two bands is a complex job. In this work this has been implemented using a novel approach of interleaving the radiating elements of both the bands over a common aperture and yet keeping the inter-element spacing within the acceptable limits. The design has been carried out at Extended C-Band to meet the objective of achieving a half power beamwidth of 5° within the constraints of minimum mass and volume. The hardware has been successfully realized and the measured return loss is better than 20dB and the isolation between the two ports is better than 30dB at the required frequencies.