A 175GHz Bandwidth High Linearity Distributed Amplifier in 500nm InP DHBT Technology

This work reports a highly linear and efficient ultra-wideband distributed amplifier in 500 nm transferred-substrate InP DHBT technology. Five unit cells each with a tricode transistor set provide the ultra-wideband properties of this amplifier. A transistor node of 500 nm is used which has an ft and fmax of 350 and 490 GHz respectively. The measurements show a small-signal gain of 12 dB with a 3-dB bandwidth of near-DC to 175 GHz. For large signal operation, the circuit reaches a 1-dB output compression point, P1dB, of 8.4 dBm at 150 GHz, a saturated output power of approximately 10 dBm, and an associated maximum PAE of 6%. This is the best linearity as well as the highest saturated output power and PAE reported at this frequency for DAs. The circuit consumes 180 mW DC power only.