A Switchable, Passively Tuneable 28 GHz to 39 GHz Upconversion Link for a 5G Repeater using a Broadside Coupler and Analog Predistortion in a 130 nm BiCMOS Technology

In this paper, a switchable, passively tuneable 28 GHz to 39 GHz upconversion link for a 5G repeater is proposed and investigated. The upconversion link features an ultra efficient method for output power level adjustment as well as a size efficient broadside coupler for control signal extraction. A tuning range of 7 dB is realized at almost no additional layout effort and zero power consumption. The design yields a measured large signal power gain of 13.8 dB and an input-referred 1 dB compression point of -7.1 dBm; a linearity improvement of 4 dB is achieved by using analog predistortion. For the broadside coupler an insertion loss of -2.2 dB and a coupling of -14 dB is realized. The broadside coupler consumes an area of 340 μm × 220μm.