A Compact Two-Level Sequentially Rotated Circularly Polarized Antenna Array for C-Band Applications

Abstract EN

A compact circular polarized antenna array with a convenient gain/bandwidth/dimension trade-off is proposed for applications in the C-band.

The design is based on the recursive application of the sequential phase architecture, resulting in a 4 × 4 array of closely packed identical antennas.

The 16 antenna elements are disc-based patches operating in modal degeneration, tuned to exhibit a broad while imperfect polarization.

Exploiting the compact dimension of the patches and a space-filling design for the feeding network, the entire array is designed to minimize the occupied area.

A prototype of the proposed array is fabricated with standard photoetching procedure in a single-layer via less printed board of overall area 80 × 80 mm2.

Adequate left-hand polarization is observed over a wide bandwidth, demonstrating a convenient trade-off between bandwidth and axial ratio.

Satisfying experimental results validate the proposed design, with a peak gain of 12.6 dB at 6.7 GHz maintained within 3 dB for 1 GHz, a very wide 10 dB return loss bandwidth of 3 GHz, and a 4 dB axial ratio bandwidth of 1.82 GHz, meaning 31% of fractional bandwidth.