A Dual Circularly Polarized SIW-Fed Phased Array Antenna With Wide-Angle Beam Scanning Range

We propose a dual circularly polarized (CP) substrate integrated waveguide (SIW) cavity-backed antenna with wide axial ratio (AR) beamwidth, which can generate the right-hand CP (RHCP) or left-hand CP (LHCP) radiation through exciting different ports. Dual CP radiations are accomplished by an SIW directional coupler (DC) in the bottom layer, which provides the desired amplitude and phase conditions for two orthogonal slots. By superposing phase centers of linearly polarized (LP) electric field elements, the proposed antenna achieves a good performance of 3 dB AR beamwidth of 165° in the desired azimuth cut plane. Furthermore, an eight-element dual CP linear phased array with a wide-angle beam scanning ability is comprised by this antenna prototype. Numerical and measured results show that the array antenna can scan its main lobe from – 59° to 58°. In general, the proposed antenna array fed by the SIW structure satisfies the requirement of a multipolarization wireless communication system for low profile, simple structure, and easy integration with planar circuits.