Enhanced design of a floating broad-band lossless tunable HBT monolithic active inductor

A floating HBT Tunable Active Inductor (TAI) MMIC is reported. Compared with FET circuit, analytical results and measurements show significant improvements over broad-band capability, tunability and selectivity (typical Q's are over 300). HF noise is also investigated and a minimum noise figure of 0.5 dB is achieved. Measured and simulated results are compared.