CRLH-SIW-based leaky wave antenna with low cross-polarisation for Ku-band applications

A novel composite right/left-handed substrate integrated waveguide (SIW)-based leaky wave antenna (LWA) is proposed. Square-ring-slot radiators are adopted to introduce series capacitor as well as the energy leakage, and four grounded vias within the slot ring contribute to part of the shunt inductor. Moreover, low cross-polarisation levels in the beam scanning plane are achieved due to the differential excitations of the radiators located along the centre line of the SIW working at TE10 mode. The antenna is fabricated and measured. Both simulated and measured results show that the proposed antenna is a balanced LWA operating in the frequency band 13.5-17.8 GHz. Continuous beam scanning characteristic is acquired within the scanning region -57° to +30°. In addition, low cross-polarisation levels less than -27 dB are obtained, and measured results are in good agreement with simulated ones.