A Low Sidelobe Wideband Slotted Antenna Array Fed by High-Order Modes Resonant Cavity

A low sidelobe wideband waveguide slotted cavity antenna is presented for K-band wireless communication. By exciting the radiation slots in high-order modes, the antenna abandons the back cavity structure, thereby reducing the profile height. And due to the combination of multiple high-order modes, it can obtain a wide impedance bandwidth of 21.9% (17.9 to 22.3 GHz). Then, an 16×16 array antenna with a peak gain of 29.1 dBi at at the center frequency of 20 GHz was designed. In the feed network, the Dolph-Chebyshev power distribution was implemented by multistage T-junction. The power distribution between the subarrays is suitably adjusted to achieve a sidelobe level below -20 dB.