MOUNTING STRUCTURE FOR TEMPERATURE DETECTION ELEMENT FOR POWER AMPLIFIER CIRCUIT

PURPOSE: To provide mounting structure for the temperature detection element for a power amplifier circuit which can make the degree of thermal coupling fixed even during vibration, for example, and can be applicable to mass production as well. CONSTITUTION: A thermistor TH1 and a varister D1 as temperature detection elements for stabilizing the operation of power amplification at a high-frequency power amplifier circuit are mounted on the surface of a sub substrate 11 different from the main substrate 10 fixed on a case while mounting transistors TR1 and TR2 for power amplification for the high-frequency power amplifier circuit. Then, the sub substrate 11 is supported on the main substrate 10 by contact pins 11 and 12 as supporting members so that the temperature detection elements TH1 and D1 can be respectively thermally coupled with the power transistors TR1 and TR2. In this case, it is preferable to mount a feedback circuit for the power amplifier circuit on the sub substrate 11.