A Frequency-Controlled Active Phased Array

A frequency-controlled active phased array is introduced for cost-effective base-station applications. The array realizes simple LO-controlled beam steering with a fixed RF frequency, but without phase shifter components. Primary beam squint and pattern distortions, often seen in typical frequency-controlled phased arrays, are substantially reduced by the use of our heterodyne-mixing scheme and new feed network structures. The MMIC amplifiers provide more than 20 dB gain for a desired RF signal at 20 GHz, and effectively suppress the unwanted sideband and spurious LO by more than 40 dB. The K-band transmitter array demonstrates up to 40 degree beam-steering within 0.5 degree scan error and less than 1.3 dB gain error during scanning.