A 110 GHz Comb Generator in a 250 nm InP HBT Technology

We report a monolithic microwave integrated-circuit (MMIC) comb generator capable of producing a repetitive narrow pulse with sharp edges. The circuit is designed in a 250-nm Indium Phosphide (InP) Heterojunction Bipolar Transistor (HBT) technology, using differential pairs in a common-emitter configuration. We characterized the output signal with a 110 GHz sampling oscilloscope and de-embed the band-limited frequency spectrum of the pulse in the circuit reference plane. We measured a pulse width of 7.1 ps and a peak amplitude of -0.333 V. In the frequency domain, the comb generator provides -48.7 dBm of output power at 110 GHz while the circuit is fed with a 1-GHz input signal.