A Parabolic Reflector Antenna with Compact Dual Circular Polarized Multilayer Microstrip Patch Feed for MEO and Next Generation LEO Local User Terminals

As part of the international COSPAS-SARSAT program, India has established Local User Terminals(LUT) at Lucknow and Bengaluru, with the Indian Mission Control Centre (INMCC) located at ISTRAC, Bengaluru, to receive and process distress alerts from satellites. The INMCC receives data from the Indian LUTs and the global network of Mission Control Centers, then disseminates timely and accurate alerts to rescue authorities. 2.4m Parabolic Reflector antenna with corrugated waveguide based feed that is being used at present for Local User Terminals, is heavy, bulky and disproportionately large compared to the size of reflector. A compact lightweight dual circular polarized multilayer microstrip patch antenna is designed as feed for the 2.4m parabolic reflector antennas used as Local User Terminal. The proposed parabolic reflector antenna with multilayer patch feed has better efficiency compared to the existing antenna. The new antenna has 14dB returnloss bandwidth of 33MHz with returnloss better than 15dB at the desired frequencies of 1.5448GHz and 1.5441GHz. The antenna has peak circular gain better than 29.4 dBi, beamwidth of 5.4 deg and axial ratio less than 3dB in frequency range of 1.5441GHzt o 1.5448GHz. Isolation better than 17dB is present between RCP and LCP ports