High power and low cross-polarization microstrip patch array antenna at S-band

This article reports the design and development of high power, low cross-polarization, and high efficiency circularly polarized microstrip patch array antenna at S-band, proposed for Indian Regional Navigation Satellite System payload. A novel feeding mechanism for truncated corner square patch based on square coaxial line for broadband impedance matching is discussed. Sequential rotation scheme for axial ratio improvement in an array is implemented. High power handling margins in critical regions of square coaxial line for multipaction breakdown is brought out. Measured 19 dB return loss bandwidth of array antenna is 15.6%. Axial ratio of 0.78 dB over global coverage is achieved in the desired frequency band of operation. (C) 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.