Phased Array Featuring Independent, Simultaneous Beamsteering for Widely Separated mmWave Dual-Band Using Compact, Low-Loss, Selective Coupler

This article introduces a new concept of a phased array that can independently and simultaneously perform beamsteering across two frequency ranges: a lower band encompassing 24 GHz and a higher band including 48 GHz. This concept is exemplified for millimeter-wave (mmWave) applications. The overall structure is realized in conjunction with a newly devised compact, low-loss, selective coupler (CLSC) feed network. The peak realized gain of the exemplified 1\times4 antenna array is 9.2 dBi at 24 GHz (fundamental frequency) and 12.2 dBi at 48 GHz (second harmonic), respectively, with a scanning angle of ±45° at both frequencies. To the best of the authors' knowledge, this work is the first to contribute to the realization of phased arrays that simultaneously operate for widely separated mmWave dual-band.