A substrate integrated slot antenna array using higher order mode feeding network

In this paper, a higher order mode cavity is adopted as the feeding networking to implement a s lot antenna array. Four resonant slots as radiation elements are cut on the higher order mode cavity symmetrically. Based on the higher order mode characteristics, both resonance cavity and antenna feeding network can be realized inherently, which makes the array more compact. In order to improve the front-to-back ratio of the array, resonant resonant slots are at the same side with the aperture coupling slot. Measured results show that the -10dB impedance bandwidth is from 8.35 GHz to 9.09 GHz (8.5%). The 3 dB gain bandwidth is beyond the impedance bandwidth, peak gain is better than 10 dBi within the bandwidth. Thanks to its feeding scheme, front-to-back ratio is better than 17 dB.