High-frequency power amplifier

Abstract

In a high-frequency power amplifier of the present invention, when a short circuit occurs between a gate or source or between a base and emitter in one of unit cells comprising a multi-cell, influence on the operations of the other normal unit cells is suppressed by a direct-current interrupting characteristic of a diode disposed for each of the unit cells.

Description

technical field [0001] The present invention relates to a wireless communication device used as a mobile device such as a mobile phone or a fixed device of a base station for communication between them in a mobile communication system such as a mobile phone network composed of a mobile phone and a base station. A high-frequency power amplifier for high-frequency signal power amplification. Background technique [0002] In recent years, as a public telephone system, mobile communication systems such as a mobile telephone network composed of a large number of mobile phones and multiple base stations have been widely used based on the convenience of being able to make calls or send emails while moving. In this mobile communication system, for example, in order to communicate between mobile phones via a base station, wireless communication devices that communicate using high-frequency signals (radio waves) are used as mobile devices such as mobile phones or fixed devices at base...

AI Technical Summary

Problems solved by technology

For the amplifying transistors of high-frequency power amplifiers used in mobile equipment of mobile communication systems and fixed equipment in base stations, gallium arsenide MESFETs with excellent basic performance and high reliability in the high-frequency region are mostly used. However, such devices are Normally-on type device, therefore, if for some reason, an appropriate voltage cannot be applied to the gate terminal, the current between the drain and the source cannot be cut off, so sometimes a leakage current exceeding the rating flows. , and even the device is destroyed

[0017] In addition, when the transistor used is a bipolar transistor, when a short circuit occurs between the base and the emitter of a failed unit cell, the base current distributed to all the unit cells flows through the failed unit. GND, so all the unit cells become cut-off, it is possible to stop the amplification function

[0018] In addition, in the existing high-frequency power amplifier, although an appropriate voltage or current can be applied to the gate terminal or the base terminal of the unit cell, if there are, for example, In the case of one fault, the fault mode is a short circuit between the gate and the source or a short circuit between the base and the emitter, until the normal unit cell that shares the gate terminal or the base terminal with the faulty unit cell cannot be applied with an appropriate bias voltage, Cannot control drain current and collector current

[0019] As a result, a drain current far greater than the rating may flow, causing burnout of the high-frequency power amplifier, burnout of the power supply path, fluctuations in operating current, etc. An incident associated with a system failure that, when it occurs, causes considerable damage

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