A Compact Multilayer Triple-Band Circularly Polarized Antenna Using Anisotropic Polarization Converter

A compact multilayer antenna enabled with anisotropic linear-to-circular (LTC) polarization converter (PC) is investigated in this letter for triple-band circularly polarized (CP) operation. The intended circularly polarized antenna provides a miniaturized size of 0.27 λ 0 × 0.27 λ 0 × 0.10 λ 0 at 2.38 GHz. The fabricated CP antenna provides extended impedance bandwidths of 13.0%, 18.2%, and 14.7% at the center frequencies of 2.38, 3.44, and 5.5 GHz, respectively. The antenna provides an axial ratio (AR) bandwidths of 3.53%, 1.73%, and 13.62%, higher gain-to-area ratio of 28.91, 39.10, and 30.28 for the three bands. Moreover, the antenna provides positive gain values and AR < 3 dB for theta = ±45°, ±46°, and ±32° and phi = 0° to 360° at 2.45, 3.52, and 5.65 GHz, respectively. Hence, the antenna is well suitable for small satellite applications.