Electronic parts for high frequency power amplifier and wireless communication device
View Patent ↗The present invention provides electronic parts for amplifying high frequency power capable of expanding a dynamic range of an output power detection circuit, obtaining a continuous detection output having no inflexion point from a low region of output power to its high region and thereby improving controllability of the output power. In a wireless communication system which controls output power of a high frequency power amplifier, based on an output power detection signal and a signal indicative of an output level, an output power detection circuit is provided with a multi-stage configured amplifier which amplifies a high frequency signal taken out via a coupler and capacitive elements. Further, a plurality of detection circuits which detect outputs of amplifiers of respective stages, and a detection circuit which detects the high frequency signal without passing through the multi-stage configured amplifier are provided. One obtained by combining the outputs of these detection circuits is inputted to an error amplifier for generating an output power control signal, as the output power detection signal to thereby generate a control signal for the high frequency power amplifier.
1. Electronic parts for amplifying high frequency power comprising:
a high frequency power amplifier which includes amplifying elements and amplifies a transmit signal having a high frequency; and
an output power detection circuit which detects the magnitude of output power of the high frequency power amplifier,
said electronic parts for amplifying high frequency power controlling gain of the high frequency power amplifier on the basis of an output of the output power detection circuit and a control signal indicating an output level thereof,
wherein the output power detection circuit includes:
a first detection circuit which detects an ac component extracted from the output of the high frequency power amplifier by a directional power coupler;
a multi-stage configured amplifier circuit which amplifies the ac component extracted from the output of the high frequency power amplifier by the directional power coupler; and
a second detection circuit constituted of a plurality of detection stages which detect outputs of respective amplifying stages of the amplifier circuit, and
wherein the output of the first detection circuit and the output of the second detection circuit are combined together and the combined output is outputted, and an attenuator is provided on the input side of the first detection circuit.
2. The electronic parts for amplifying high frequency power according to claim 1 , wherein the attenuator comprises a plurality of capacitive elements or a plurality of resistive elements connectable between the input terminal of the first detection circuit and a constant potential point, and the plurality of capacitive elements or the plurality of resistive elements are on-chipped elements formed in the same semiconductor substrate as a semiconductor substrate formed with the elements that constitute the output power detection circuit.
3. The electronic parts for amplifying high frequency power according to claim 2 , wherein the plurality of capacitive elements or the plurality of resistive elements are selectively connected between the input terminal of the first detection circuit and a constant potential point according to the presence or absence of wiring formed by master slices in a wiring forming step.
4. The electronic parts for amplifying high frequency power according to claim 2 , wherein the attenuator is provided with a plurality of switch elements connected in series with the plurality of capacitive elements or the plurality of resistive elements, and the plurality of capacitive elements or the plurality of resistive elements are selectively connected between the input terminal of the first detection circuit and a constant potential point according to on/off states of the plurality of switch elements.
5. The electronic parts for amplifying high frequency power according to claim 4 , wherein the directional power coupler is a coupling capacitor constituted of a wiring pattern formed over an insulated board with a semiconductor substrate formed with the elements constituting the first detection circuit being mounted thereover.
6. The electronic parts for amplifying high frequency power according to claim 5 , further comprising a first high frequency power amplifier circuit which amplifies a transmit signal having a first frequency, a second high frequency power amplifier circuit which amplifies a transmit signal having a second frequency different from the first frequency, a first directional power coupler which takes out an ac component from an output of the first high frequency power amplifier circuit, and a second directional power coupler which takes out an ac component from an output of the second high frequency power amplifier circuit,
wherein the output power detection circuit is provided as a common circuit which detects the ac component taken out by the first directional power coupler and the ac component taken out by the second directional power coupler, and the attenuator is configured in such a manner that switch elements brought to an on state according to whether the output power detection circuit detects the ac component taken out by either one of the directional power couplers are switched.
7. A wireless communication device comprising:
electronic parts for amplifying high frequency power defined in claim 4 ; and
a baseband circuit which generates a transmit signal to be amplified by the electronic parts for amplifying high frequency power,
wherein control information indicating whether the plurality of switch elements should respectively be an on state or an off state, is supplied from the baseband circuit to the electronic parts for amplifying high frequency power.
8. The electronic parts for amplifying high frequency power according to claim 1 , wherein the attenuator comprises a plurality of parallel-configured resistive elements connectable in series with a capacitive element between an input terminal common to the first detection circuit and the second detection circuit and the input terminal of the first detection circuit, and the plurality of resistive elements are on-chipped elements formed in the same semiconductor substrate as a semiconductor substrate formed with the elements that constitute the output power detection circuit.