A Dual-Wideband Cavity-Backed Antenna by Using Waveguide Transition and Short-Ended Groove Loading

A novel scheme is presented to control the frequency response on an open-ended waveguide antenna. A groove is loaded in the waveguide that is used to independently control the frequency response of the antenna without affecting the radiation pattern, and a transition is used to provide additional control. A dual-wideband antenna is taken as an example to verify the effectiveness of the scheme. To demonstrate the idea, an antenna element and its
$2\times2$
array were designed, fabricated, and measured. Reasonable agreement between the measured and simulated results has been observed. The measured 10 dB impedance bandwidths of the lower and upper bands of the proposed element are achieved to be more than 22.2% and 14.2%, respectively, fully covering the 26/28 GHz band (24.25–29.5 GHz) and 39 GHz (37–40 GHz) band.