A 10-14 GHz linear MMIC vector modulator with less than 0.1 dB and 0.8 degrees amplitude and phase error

The design, fabrication, and performance of a GaAs monolithic linear vector modulator in the 10-14-GHz band are described. The vector modulator consists of four monolithic microwave integrated circuit (MMIC) chips (a quadrature power splitter, two binary phase shift keying (BPSK) modulators, and a Wilkinson power combiner) and is mounted in a microwave test fixture with input-output isolation of greater than 60 dB. The total area occupied by the four MMIC chips is less than 11 mm/sup 2/, and the total power consumption is less than 1.6 W. The circuit exhibits sideband and carrier rejections of more than 45 dB with third-order intermodulation signals at -40 dBc.<>