Integrated digitally controlled 6-bit phase shifter, 4-bit attenuator, and T/R switch using multifunction self aligned gate process

A monolithic microwave and digital integrated circuit (MMDIC) consisting of a 12-b serial-to-parallel converter, 6-b phase shifter, 4-b attenuator, and a single-pole double-throw (SPDT) switch has been designed and fabricated using the standard multifunction self-aligned gate (MSAG) process, with a full functional yield of over 27%. By combining digital circuitry with these microwave control circuits, the number of control lines is reduced from 16 to 3. The on-chip combination of multiple circuit functions, including both digital and microwave, not only simplifies the bonding connections, but also reduces the subsystem cost, and increases its reliability.<>