| 摘要 |
A GSM system and an EDGE system much different in gain are incorporated into a single high frequency power amplifier module. In a high frequency power amplifier module having a multi-stage amplifying configuration, which is used in a GSM mode and an EDGE mode according to switching, a first-stage amplifier comprises a dual gate MOSFET. In the EDGE mode, an APC signal or a selected and fixed potential is supplied to a first gate electrode of the dual gate MOSFET. Further, Vgs (Vgs1, Vgs2 and Vgs3) of respective transistors of from a first stage to a third stage are fixed in potential form or supplied as APC signals, and the gain in the EDGE mode is matched with that in the GSM mode, whereby the generation of noise is reduced.
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