A recent discovery indicates that the current sign of AlGaAs/GaAs HBTs can be externally modulated by biasing an extra Schottky electrode that contacts the emitter passivation ledge directly. This discovery leads to the possibility of implementing complex RF AGC (automatic-gain-control) and signal mixing functions within a 4-terminal HBT (FHBT) at relatively low power supply voltages (down to Vcc=1.8V). This low voltage operation has been extremely difficult for the conventional Gilbert-cell mixer design based on regular 3-terminal HBTs. The demonstrated FHBT AGC has 24dB gain control up to 6GHz and the mixer has 7dB conversion gain and -12.5dBm IIP3 without emitter or base degeneration.
|Number of pages||4|
|State||Published - 1 Jan 2001|
|Event||2001 IEEE Radio Frequency Integrated Circuits (RFIC) - Phoenix, AZ, United States|
Duration: 20 May 2001 → 22 May 2001
|Conference||2001 IEEE Radio Frequency Integrated Circuits (RFIC)|
|Period||20/05/01 → 22/05/01|