28 GHz omni-directional quasi-optical transmitter array

Omni-directional base stations are needed in many emerging wireless communication systems. This paper presents the first adaptation of a quasi-optical oscillator array for this purpose. A 28 GHz active oscillator element containing a modified Vivaldi endfire antenna is utilized as the unit cell. Twelve of these are incorporated into the circular array, which is powered from a single DC power supply. The array has a high combining efficiency and remains frequency-locked over a span of 600 MHz.<
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