Monolithic, lumped element, single sideband modulator

The design and performance of a monolithic single sideband modulator that uses lumped element technology to achieve a compact circuit are described. The circuit comprises two balanced mixers, a branch line hybrid to input the carrier frequency, and a Wilkinson power combiner for summing the two mixer outputs. For this design, the carrier frequency was 6.9 GHz and the modulating signal was in the range of 0-500 MHz. The lower sideband was 6.4 to 6.9 GHz and the upper sideband was 6.9 to 7.4 GHz. Upper bounds on the performance of the modulator were derived from an assessment of the circuit components based on computer simulations.<>