| 摘要 |
<p>The present invention provides a high-frequency power amplifying device capable of transmitting output power at high efficiency. For example, a high-frequency power amplifying device has first and second differential amplifiers and a transformer for matching output impedances of the differential amplifiers. Between differential output nodes of the first differential amplifier, an inductor, a switch, and an inductor are coupled in series. When the second differential amplifier is in an operating state and the first differential amplifier is in a non-operating state, the switch is controlled to be on. In this case, due to "off capacitance" in transistors of a differential pair included in the first differential amplifier, impedance on the first differential amplifier side seen from both ends of primary coils becomes a high impedance state (parallel resonance state) and, equivalently, the primary coils do not exert influence on the operation of the second differential amplifier.</p> |
