Two-dimensional beam-scanning linear active leaky-wave antenna array usingcoupled VCOs

An active phased-array design for electronic two-dimensional beam scanning using a phase-shifterless linear one-dimensional active leaky-wave antenna array is demonstrated. The varactor-tuned voltage-controlled oscillators (V COs) and coupling network are implemented in this array. Three coupling net works are designed and compared for optimum coupling strength between each VCO element. The measured pattern of a 4 x 1 active leaky-wave antenna arra y shows that the main beam can be continuously scanned from 68 degrees to 4 0 degrees in elevation, as the frequency varies from 8.24GHz to 9.15GHz. Th is is equivalent to over 10% electronic tuning bandwidth. By tuning the fre e-running frequencies of the end elements, the main beam can be continuousl y scanned from -26 degrees to +10 degrees from broadside with azimuth symme try in a conical scan manner.