UNIFORM BALLAST RESISTANCE FOR A THERMALLY BALANCED RADIO FREQUENCY POWER TRANSISTOR

摘要

An RF power transistor (10) having improved thermal balance characteristics includes a first emitter electrode (12) and a base electrode (18) formed on a silicon die, each having a multiplicity of parallel electrode fingers. A second emitter electrode (22) is formed over the base electrode (18) and is electrically connected to the first emitter electrode (12). Ballast resistors (28, 30) are formed in a substantially evenly spaced manner on each side of the silicon die, in series with at least some of the electrode fingers (16) of the first emitter electrode (12) and in series of at least some of the electrode fingers (26) of the second emitter electrode (22).