Active aperture-coupled leaky-wave antenna

An active aperture-coupled leaky-wave antenna which is integrated with a varactor-tuned high electron mobility transistor voltage-controlled oscillator (HEMT VCO) is presented. To excite the first higher mode of the microstrip, the aperture-coupled structure is used and a sequence of covered wire is added at the centre of this antenna to suppress the dominant mode. The measured H-plane main beam can be continuously scanned 10° as the HEMT VCO frequency is varied from 9.05 to 9.5 GHz. This feeding structure is very suitable for active phase antenna array applications