A Broadband High-Gain 25–48-GHz Vector Modulator in a 130-nm BiCMOS Technology

This paper presents a broadband bootstrapped frequency doubler followed by a static frequency divider-based IQ signal generation chain providing fully differential signals to variable gain amplifiers, creating a vector modulator. The maximum locking range is from 12.8 GHz to 49.1 GHz, corresponding to a 117 % relative bandwidth. The system achieves a 3dB-bandwidth of 23 GHz (from 24.8 GHz to 47.8 GHz) with -7 dBm input power. The peak gain is greater than 30dB and it exhibits low RMS phase and gain errors of less than 2.8° and 0.55 dB, respectively. The maximum output power of the vector modulator is 2.2 dBm.