Dual-Band and Dual-Circularly Polarized Shared-Aperture Array Antennas With Single-Layer Substrate

• Published in: IEEE transactions on antennas and propagation Vol. 64; no. 1; pp. 109 - 116
• Main Authors: Zhang, Jin-Dong, Wu, Wen, Fang, Da-Gang
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.01.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna arrays; Antennas; Arrays; Bands; Bandwidth; Dual band; Dual bands; dual circular polarizations; Feeds; Narrowband; Networks; Prototypes; sequential rotation technique; shared-aperture array; single layer; Substrates; single layer; sequential rotation technique; Dual bands; dual-circular polarizations (CPs); shared-aperture array
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2015.2501847

This paper presents a new approach to implement planar shared-aperture dual-band dual-circular polarization (CP) array antennas. The antennas can be fabricated on a single-layer substrate and extended to a larger array easily. In this approach, each array element is obtained by connecting two patches working at different frequencies directly. To form arrays with higher gain, two kinds of feed networks are described, which can be applied in systems where narrowband and wideband are needed, respectively. One is using the conventional feed network and the other is using the sequential rotation technique to further improve the CP axial ratio (AR) performance. Two prototype arrays with 4 \times 4 elements are fabricated and tested in X/Ku bands. Experimental results show that good CP characteristics are obtained, which agree well with the simulation results. For the first narrow-band prototype array, the 3-dB AR bandwidth is around 1.5% for both bands. For the second array using the sequential rotation technique, the bandwidth of return loss and AR are wider. In the lower band centered at 12.1 GHz, the {-}10\hbox{-}\text{dB} return loss bandwidth is 8.3% and the 3-dB AR bandwidth is 14.2% [right-hand CP (RHCP)]; in the higher band centered at 17.4 GHz, the corresponding data are 18.9% and 14.9% [left-hand CP (LHCP)], respectively.