A two-dimensional beam-scanning linear active leaky-wave antenna array

This letter presents a new technique fur electronic two-dimensional beam sc anning using a phase-shifterless linear active leaky-wave antenna array. Th e varactor-tuned voltage-controlled oscillators (VCO's) and coupling networ k are implemented in this array. The measured pattern of this 4 x 1 leaky-w ave antenna array shows that the main beam can be continuously scanned from 68 degrees to 40 degrees in elevation as the frequency varied from 8.24 to 9.15 GHz. By tuning the free-running frequencies of the end elements, the main beam can be continuously scanned from -26 degrees to +10 degrees in az imuth, A maximum ERP of 667 mW is measured at 8.9 GHz for this active anten na array.