Power amplifier module
AssigneeRenesas Technology Corp.
InventorsKiichi Yamashita, Tomonori Tanoue, Shizuo Kondo
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AssigneeRenesas Technology Corp.
InventorsKiichi Yamashita, Tomonori Tanoue, Shizuo Kondo
Estimating the term…
The present invention provides a power amplifier module featuring that: its output power characteristic smoothly changes as the input control voltage changes; and its control sensitivity is stable over a wide dynamic range. By same means, idling current for gain setting is supplied to a single amplifier element or all of multiple stages of amplifier elements of the power amplifier module. By making this idling current behave so as to exponentially change, relative to input control voltage, the invention enables output power control proportional to the input control voltage.
A power amplifier module comprising:
A power amplifier module comprising:
A power amplifier module comprising:
A power amplifier module comprising:
A power amplifier module comprising:
A power amplifier module comprising:
A power amplifier module comprising:
A power amplifier module comprising:
A power amplifier module comprising:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements: modifications of…
Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements: modifications of…
Power amplifiers, e.g. Class B amplifiers, Class C amplifiers: with semiconductor devices only
Volume compression or expansion in amplifiers: without controlling loop
Term ended 20 Oct 2020 (estimated)
The present invention relates to a power amplifier module, particularly to a technology that is effectively applied to a power amplifier module for a cellular phone system with the capability of output power control to be used on portable terminal equipment used in a mobile communication system.
Significant growth has lately been found in the market of cellular phone systems, typically, such as a Global System for Mobile Communication (GSM) and a Personal Communication Network (PCN) and this tendency is anticipated to continue in the future. One of the requirements of such systems as GSM and PCN is that the output power of portable terminal equipment can be controlled, dependent on the distance from a base station to the equipment. This can be fulfilled by controlling the gain of the power amplifier module installed on the equipment.
FIG. 9 shows an example of a typical conventionally used power amplifier module with three stages of output power control. In this power amplifier module, a signal input through a pin 062 is amplified by first-stage, second-stage, third-stage amplifiers 601, 602, 603, and output through a pin 064. Power source voltage is applied to a pin 063. At this time, an output power control circuit 607 controls the gains of the amplifiers 601, 602, and 603 by changing an idling current that determines a DC bias of transistors 604, 605, and 606. Hetero-Bipolar Transistors (GaAsHBTs) are used as the transistors 604, 605, and 606.
Other objects and advantages of the invention will become apparent during the following discussion of the accompanying drawings, wherein:
FIG. 1 is a basic circuit diagram showing a power amplifier module as a preferred embodiment of the present invention;
FIG. 2 is a circuit diagram showing a power amplifier module as another preferred embodiment of the present invention;
FIG. 1 shows a basic circuit diagram of a power amplifier module as a preferred embodiment of the present invention. Any of the circuit elements in FIG. 1 is a discrete circuit module comprising a single semiconductor integrated circuit or a plurality of semiconductor integrated circuits and an external component connected to it or them. The power amplifier module of first embodiment comprises an amplifier 6 that consists of an output transistor 2, an adjustment circuit 4, and coupling capacitance 5 and an output power control circuit 1 that consists of a V-I logarithmic conversion circuit 11, a constant current source 7, input transistors 3 and 8, and an impedance circuit 9.
The V-I logarithmic conversion circuit 11 executes logarithmic conversion of an input control voltage, that is input through a pin 03, into current. This circuit 11 enables the idling current in the output transistor 2 to exponentially change, relative to the input control voltage. The transistor 8 supplies the DC component of a base current that is generated, as an increment by the self-bias effect during the large-signal operation mode, and flows across the output transistor 2.
The impedance circuit 9 is used to prevent the instability of operation due to that a high-frequency signal of the input signals input through the pin 01 flows through the above-mentioned input transistor 3. Reference number 04 is a power source pin. The input transistor 3 forms a current mirror circuit in conjunction with the output transistor 2 and has a current sensing function. Therefore, when a reference current from the constant current source 7 is allowed to flow across the input transistor 3, current that is as large as mirror ratio times the reference current is allowed to flow across the transistor 3 as the idling current.