Patent ID: 8183933
Filing Date: 2012-05-22
Classification: H03F,H04B

Abstract:
1. An amplifier circuit, comprising: a first transistor in a common-collector configuration having a base and a collector, the base of the first transistor coupled to an input node for receiving a pulsed signal, the collector of the first transistor coupled to a first voltage source node; and a heterojunction bipolar transistor (HBT) in a common-emitter configuration having a base coupled to an emitter of the first transistor, a collector of the HBT coupled to a second voltage source node for biasing the HBT such that the HBT is normally off, the HBT operating isothermally when the pulsed signal has a short-pulse width and a low-duty-cycle, wherein the first transistor drives the HBT when the pulsed signal is received at the base of the first transistor to output an amplified pulsed signal at the collector of the HBT.