High-frequency amplifier, transmitting device and receiving device

A transmitter for transmitting radio waves comprising:

• baseband signal processing means for processing a baseband signal;
• modulating means for modulating a predetermined signal using said baseband signal;
• and
• power amplifying means for amplifying a radio frequency signal comprising a plurality of active element groups, wherein each of said groups comprises one or more FETs for amplifying said signal, with input terminals of said one or more FETs combined to form a single input terminal and output terminals of said one or more FETs combined to form a single output terminal;
• and
• bias control means for controlling gate bias voltages of said FETs of said plurality of active element groups, wherein each of said plurality of groups is separately biased so that a number of groups that are biased to amplify said signal is selectable by said bias control means, whereby a gain of said plurality of active element groups is selectable.

A transmitter for transmitting radio waves comprising:

• baseband signal processing means for processing a baseband signal;
• modulating means for modulating a predetermined signal using said baseband signal;
• and
• power amplifying means for amplifying a radio frequency signal comprising a plurality of active element groups, wherein each of said groups comprises one or more FETs for amplifying said signal, with input terminals of said one or more FETs combined to form a single input terminal and output terminals of said one or more FETs combined to form a single output terminal;
• and
• bias control means for controlling drain voltages of said FETs of said plurality of active element groups, wherein drain voltages for said FETs in each of said active element groups are individually controlled, so that a number of groups that amplify the signal is selectable by said bias control means, whereby a gain of said plurality of active element groups is selectable.

A receiver for receiving a radio frequency signal comprising:

• radio frequency amplifying means for amplifying received radio frequency signal comprising a plurality of active element groups, wherein each of said groups comprises one or more FETs for amplifying said signal, with input terminals of said one or more FETs combined to form a single input terminal and output terminals of said one or more FETs combined to form a single output terminal;
• bias control means for controlling gate bias voltages of said FETs of said plurality of active element groups, wherein each of said plurality of groups is separately biased so that a number of groups that is biased to amplify said signal is selectable by said bias control means, whereby a gain of said plurality of active element groups is selectable;
• demodulating means for demodulating an output signal of said radio frequency amplifying means;
• and
• baseband signal processing means for processing an output signal of said demodulating means.

A receiver for receiving a radio frequency signal comprising:

• radio frequency amplifying means for amplifying a received radio frequency signal comprising a plurality of active element groups, wherein each of said groups comprises one or more FETs for amplifying said signal, with input terminals of said one or more FETs combined to form a single input terminal and output terminals of said one or more FETs combined to form a single output terminal;
• bias control means for controlling drain voltages of said FETs of said plurality of active element groups, wherein drain voltages for said FETs in each of said active element groups is individually controlled, so that a number of groups that amplify the signal is selectable by said bias control means, whereby a gain of said plurality of active element groups is selectable;
• demodulating means for demodulating an output signal of said radio frequency amplifying means;
• and
• baseband signal processing means for processing an output signal of said demodulating means.

A transceiver for transmitting and receiving radio signals comprising:

• a transmitting section including:
• baseband signal processing means for processing a baseband signal;
• modulating means for modulating a predetermined signal using said baseband signal;
• power amplifying means for amplifying a radio frequency signal having a first plurality of active element groups, wherein each of said groups includes one or more FETs for amplifying said signal, with input terminals of said one or more FETs combined to form a single input terminal and output terminals of said one or more FETs combined to form a single output terminal;
• and
• bias control means for controlling gate bias or drain voltages of said FETs of said first plurality of active element groups, wherein each of said plurality of groups is separately biased, so that a number of groups that are biased to amplify said signal is selectable by said bias control means, whereby a gain of said plurality of active element groups is selectable;
• and
• a receiving section including:
• a second plurality of active element groups, wherein each of said groups includes one or more FETs for amplifying a received signal, with input terminals of said one or more FETs combined to form a single input terminal and output terminals of said one or more FETs combined to form a single output terminal;
• bias control means for controlling gate bias voltages of said FETs of said second plurality of active element groups, wherein each of said plurality of groups is separately biased, so that a number of groups that are biased to amplify said signal is selectable by said bias control means, whereby a gain of said plurality of active element groups is selectable;
• demodulating means for demodulating an output signal of said second plurality of active element groups;
• and
• baseband signal processing means for processing an output signal of said demodulating means.

A method of controlling a gain of a radio frequency amplifier comprising the steps of:

• sending a command for turning on or off signals to a plurality of bias controlling lines;
• adjusting bias voltages on said bias control lines so that selected parallel-connected amplifying units are activated to amplify an input signal and so that deselected parallel-connected amplifying units are deactivated, in accordance with said turning on or off of said sending step;
• and
• providing an input signal to said selected and deselected parallel-connected amplifying units, wherein a gain applied to said input signal depends on a number of said selected units.