Compact Wideband E-Slotted E-Shaped Patch Antenna for Ku-Band Phased Array Applications

The design approach and analysis of a compact wideband cavity-backed E-slotted E-shaped patch antenna is proposed in this article. In the proposed configuration, an E-shaped patch is imprinted on an E-shaped slot to provide a slot around the patch antenna. When the patch is excited by the coaxial probe, surface currents travel a wider area due to the modified structure, resulting in increased bandwidth. The resultant resonant frequencies correspond to 15.5 and 17.5 GHz, which are close to each other. Unlike the conventional E-shaped patch antenna, the proposed antenna offers 21.5% of the impedance bandwidth, compact structure, and improved radiation characteristics. To avoid grating lobes in a phased array antenna, the size of the proposed antenna is restricted to 0.854 λ
_g
× 0.854 λ
_g
, where λ
_g
is the guided wavelength at 18 GHz. It operates in linear polarization with achieved cross polarization of better than <−18 dB over the operating band and the radiating element is fabricated and tested. It attains a fractional bandwidth of 21.5% (14.5–18 GHz) in measurements. The peak gain of the antenna is 6.5 dBi at 16 GHz and 4.7 dBi at 17 GHz, respectively. The antenna could be directly mated with either brick or tile plank T/R module, and it serves well in most Ku-band phased array applications, communication, and satellite applications.