A Compact Dual Circularly Polarized Microstrip Patch Array With Interlaced Sequentially Rotated Feed

• Published in: IEEE transactions on antennas and propagation Vol. 64; no. 11; pp. 4933 - 4936
• Main Authors: Shen, Yizhu, Zhou, Shi-Gang, Huang, Guan-Long, Chio, Tan-Huat
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.11.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna measurements; Arrays; Bandwidth; Circular polarization; Dual circular polarization; Feeds; Ground plane; interlaced subarrays; Microstrip; Microstrip antenna arrays; microstrip patch array; Ports (Computers); Power dividers; sequentially rotated feed; Substrates
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2016.2600747

This communication presents a microstrip patch array, using sequentially rotated feed networks to achieve dual circular polarization in the same band. By interlacing the microstrip patches of adjacent 2 × 2 subarrays, the element spacing is minimized to avoid the challenging grating lobe issue. In this manner, the number of radiating elements is reduced from the conventional 4N to 2N + 2, where N is the number of 2 × 2 subarrays. The array is implemented on a two-layer substrate, with the upper layer hosting the microstrip patch array and the sequentially rotated networks, and the lower layer hosting the power dividers, sharing a common ground plane in the middle. To validate this novel configuration, a prototype is fabricated and measured. It achieves both |S11| <; -10 dB and axial ratio .3 dB bandwidth of 12.5% (4.95-5.61 GHz) for right-hand circular polarization and 14.7% (5.05-5.85 GHz) for left-hand circular polarization. The isolation between the orthogonal circularly polarized ports is about 12 dB in band.