Title :
Variable-load constant efficiency power amplifier for mobile communications applications
Author :
Leuzzi, G. ; Micheli, C.
Author_Institution :
Dept. of Electr. Eng., L´´Aquila Univ., Italy
Abstract :
A SiGe HBT Class-B power amplifier has been developed with a voltage-controlled variable load, for constant efficiency also at low-power levels. The output matching network includes varactor diodes that can change the load impedance at the collector of the transistor. The load line can therefore he adjusted to provide a variable output power saturation level shifting the peak of the efficiency to the desired power level. Constant efficiency over a wide output power range is obtained. This amplifer minimises power consumption for variable output power applications as required in mobile communications systems.
Keywords :
Ge-Si alloys; UHF integrated circuits; UHF power amplifiers; bipolar analogue integrated circuits; impedance matching; mobile communication; varactors; HBT Class-B power amplifier; load impedance; minimised power consumption; mobile communications applications; output matching network; power saturation level; varactor diodes; variable matching network; variable-load constant efficiency power amplifier; voltage-controlled variable load; Diodes; Germanium silicon alloys; Heterojunction bipolar transistors; Impedance matching; Mobile communication; Power amplifiers; Power generation; Silicon germanium; Varactors; Voltage;
Conference_Titel :
Microwave Conference, 2003. 33rd European
Print_ISBN :
1-58053-834-7
DOI :
10.1109/EUMC.2003.1262297
