Slotted Substrate-Integrated Waveguide Leaky-Wave Antenna with Improved Backward Scanning Bandwidth and Constant Gain in X-band

An H-shaped slotted leaky-wave antenna (LWA) is proposed based on balanced composite right/left-handed (CRLH) transmission lines (TLs) to improve the backward scanning bandwidth and achieve constant gain. The proposed antenna consists of a substrate-integrated wave guide (SIW) unit cellarray configured by an H-shaped slot cut in the top layer of the SIW and a patch embedded beneath the H-shaped slot. The proposed design improves the backward scanning bandwidth compared toplanar SIW LWAs. The measured beam radiation is in the range from-79 degrees to 80 degrees over the frequencyrange of 7.6-12.5 GHz. Moreover, a constant gain of greater than 10 dB is achieved over the entireX-band frequency range