Circularly Polarized Antenna With Specified AR and Gain Beamwidth for Spaceborne Applications

For spaceborne antennas, the gain and axial ratio (AR) within a specified beamwidth usually should be considered due to the coverage area requirement. As a result, this letter presents a circularly polarized antenna with the specified gain and AR beamwidth for spaceborne applications. The antenna with a totally circular structure is proposed to realize the specified gain and AR within the beamwidth of 130°. It is composed of one patch and two cavities. The working mechanism is presented. It can fully fulfill the requirements in the operational passband from 5.8 to 6.5 GHz. To verify the design, the antenna is fabricated and measured. The simulated results agree well with the measured ones. For the measurement results, within the beamwidth of 130°, the realized gain is larger than -0.7 dBic, and the spatial AR is better than 3.3 dB. The average boresight gain is 5.37 dBic. This indicates that the proposed antenna is a good candidate for spaceborne applications.