A Submillimeter Wave InP HEMT Multiplier Chain

In this letter, we demonstrate the first 400 GHz multiplier chain with integrated buffer amplifiers through the chain. The x9 multiplier chain uses 25 nm InP HEMT MMIC technology. The chain consists of three packaged MMICs in split-block waveguide packages with each multiplier incorporating an integrated output buffer. We report a peak output of 6.9 mW and greater than 4 mW over a 10% bandwidth.