A highly integrated two channel MMIC down converter with gain control

A complete MMIC (monolithic microwave IC) down converter with variable-gain control has been fabricated. A 6-8-GHz RF input signal is converted using a fixed 10-GHz LO (local oscillator), to a two-channel 2-4-GHz IF. The die is highly integrated, including an RF preamplifier, a double-balanced mixer, an LO amplifier, a power divider, IF amplification, and two voltage-controlled IF amplifiers which provide variable-gain adjustment. Back vias are utilized to establish grounding for both DC and RF. Probe pads are also included for measuring chip-level performance. A circuit description, the design techniques, and measured performance results are presented.<>