Two-dimensional beam-scanning linear active leaky-wave antenna array using coupled 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 (VCOs) and coupling network are implemented in this array. Three coupling networks are designed and compared for optimum coupling strength between each VCO element. The measured pattern of a 4×1 active leaky-wave antenna array shows that the main beam can be continuously scanned from 68° to 40° in elevation, as the frequency varies from 8.24 GHz to 9.15 GHz. This is equivalent to over 10% electronic tuning bandwidth. By tuning the free-running frequencies of the end elements, the main beam can be continuously scanned from -26° to +10° from broadside with azimuth symmetry in a conical scan manner