Near‐field approach towards enhanced suppression of cross‐polarised radiation across different elevation planes using novel epsilon‐shaped clusters of shorting pins

Abstract

A circular microstrip patch antenna with novel epsilon (ϵ)‐shaped clusters of shorting pins (ECSP) is proposed in this paper to emphasise the improvement of cross‐polarisation (XP) suppression across different elevation planes of radiation at ϕ=0°, 45°, 90°, and 135° rather than considering only the principal radiation planes. The near‐field approach has been adopted to understand the basic of XP radiation from the antenna. The placement of two ECSP structures symmetrically along the H‐plane of the conventional circular microstrip patch antenna (CMPA) effectively suppresses its XP radiation not only across the principal radiation planes by 57 dB at the boresight and 26 dB over the tracking angle ±45° but also across the diagonal radiation planes by 58 dB at the boresight and 2 dB over the tracking angle ±45°. A detailed analysis on the evolution of ECSP structures from arc‐shaped clusters of shorting pins (ACSP) is presented. Symmetric distribution of antenna fields in the near‐field region results in better XP suppression in the far‐field region. The proposed design offers a considerably high gain of 8 dBi at the boresight. The fabricated prototype of the proposed design shows satisfactory agreement with the simulated results.