Design of Dual-Resonant Enhanced Backfire Ring Sector Patch Antenna

A wideband dual-resonant enhanced backfire ring sector patch antenna (RSPA) with low-profile is proposed. The key parameters of the antenna are precisely calculated according to the mode synthesis design function of the ring sector patch radiator, leading to the obtained initial size of the antenna. The enhanced backfire radiation characteristic can be evolved from a bent microstrip leaky-wave antenna. As validations, a ring sector patch antenna with the flared angle α = 90° is fabricated, tested and verified on air substrate with thickness h = 5.0 mm (i.e., 0.048-wavelength) at the center frequency. The proposed antenna with the out/inner radii ratio of 1.7 exhibits an impedance bandwidth up to 25.8%. It exhibits an enhanced backfire radiation within the high frequency-band, with backfire gain up to 2.0 dBi, boresight gain up to 7.0 dBi and average radiation efficiency of 96.1%.