Enhancement of axial ratio‐beamwidth of X‐band composite microstrip patch antenna with conical ground plane

A single‐feed circularly polarised (CP) composite microstrip patch antenna (MPA) with a 3D conical ground plane at X‐band is presented here to meet the requirements of wide beamwidth for on‐board antenna structures of highly rotating bodies in projectile motion. The results of the measurement for fabricated antenna in the anechoic chamber show that a half power beamwidth and axial ratio (AR) beamwidth are achieved for right‐hand CP radiation pattern in both the xoz and yoz planes with a gain of . The AR at the resonating frequency of 10.28 GHz has a low figure of 0.46 dB producing nearly smooth CP foot print with a wide AR beamwidth. The measured reflection coefficient ( ) of CP–MPA is at 10.28 GHz with an impedance bandwidth that is 8.75% of the resonant frequency. The figure of merit for cross‐polarisation in the fabrication is , i.e. achieved at the zenith of co‐polarisation.