High-frequency amplifier, transmitting device and receiving device

• US 5,903,854 A
• Filed: 04/23/1996
• Issued: 05/11/1999
• Est. Priority Date: 04/27/1995
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Yamaura, Tomoya, Abe, Masayoshi, Oshiba, Katsuyuki
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Armstrong, Darnell R.
• Application Number:
  US08/636,405
• Time in Patent Office: 1,113 Days
• Field of Search: 455/73, 455/84, 455/88, 455/558, 455/575, 455/572, 455/91, 455/127, 330/295, 330/278, 330/279, 330/129, 330/124 R, 330/277, 330/296
• US Class Current: 455/575.1
• CPC Class Codes: H03F 1/0277 Selecting one or more amplifiers from a plurality of amplifiers
• CPC Class Codes: H03F 1/3205 in field-effect transistor amplifiers
• CPC Class Codes: H03F 2200/18 the bias of the gate of a FET being controlled by a control signal
• CPC Class Codes: H03F 2203/21178 Power transistors are made by coupling a plurality of single transistors in parallel
• CPC Class Codes: H03F 2203/7206 the gated amplifier being switched on or off by a switch in the bias circuit of the amplifier controlling a bias voltage in the amplifier
• CPC Class Codes: H03F 2203/7227 the gated amplifier being switched on or off by a switch in the supply circuit of the amplifier
• CPC Class Codes: H03F 2203/7236 the gated amplifier being switched on or off by putting into parallel or not, by choosing between amplifiers by (a ) switch(es)
• CPC Class Codes: H03F 3/1935 with junction-FET devices
• CPC Class Codes: H03F 3/211 using a combination of several amplifiers H03F3/60 takes precedence
• CPC Class Codes: H03G 1/0088 using discontinuously variable devices, e.g. switch-operated
• CPC Class Codes: H03G 3/3042 in modulators, frequency-changers, transmitters or power amplifiers transmission power control in bidirectional transmission systems H04W52/04
• CPC Class Codes: H04B 1/0483 Transmitters with multiple parallel paths

Abstract

A radio frequency amplifier, for amplifying a radio frequency signal, comprises a plurality of active element groups, each comprising one or more active elements for amplifying a signal, with input terminals of said one or more active elements being combined to form a single input terminal and output terminals of said one or more active elements being combined to form a single output terminal and bias control means for controlling bias conditions of said plurality of active element groups arranged in such a manner that at low power output deterioration of the gain and distortion characteristics of the amplifier is avoided and sufficiently low power consumption can be achieved by switching the bias voltages of each of the active element groups of the high-frequency amplifier individually between an operating voltage and an off voltage.

Claims

1. A radio frequency amplifier for amplifying a radio frequency signal comprising:

power amplifying means for amplifying said radio frequency signal based on at least one of a signal strength level of said radio frequency signal and an instruction signal included in said radio frequency signal, said power amplifying means including a plurality of active element groups connected in parallel, wherein each of said plurality of active element groups comprises one or more active elements for amplifying a signal, with input terminals of said one or more active elements being combined to form a single input terminal and output terminals of said one or more active elements being combined to form a single output terminal;

power control means for receiving said at least one of said signal strength level and said instruction signal and producing a power control information signal; and

bias control means connected to a respective control structure of each of said one or more active elements for individually controlling bias voltages of said active elements of said plurality of active element groups based on said power control information signal from said power control means, wherein each of said plurality of active element groups is separately biased so that a number of said plurality of active element groups that are biased to amplify said radio frequency signal is selectable by said bias control means such that a gain of said plurality of active element groups is selectable.

2. The radio frequency amplifier according to claim 1, wherein said one or more active elements comprise FETs, said control structure is a gate of each of said FETs, and said bias control means controls respective gate bias voltages of said FETs.

3. The radio frequency amplifier according to claim 1, wherein said one or more active elements comprise FETs, said control structure is a drain of each of said FETs, and said control means controls respective drain voltages of said FETs.

4. The radio frequency amplifier according to claim 2, wherein each of said plurality of active element groups comprises an equal number of FETs.

5. The radio frequency amplifier according to claim 3, wherein each of said plurality of active element groups comprises an equal number of FETs.

6. The radio frequency amplifier according to claim 2, wherein two or more groups of said plurality of active element groups comprise different numbers of FETs.

7. The radio frequency amplifier according to claim 3, wherein two or more groups of said plurality of active element groups comprise different numbers of FETs.

8. The radio frequency amplifier according to claim 6, wherein each of said plurality of active element groups comprises 2n FETs, where n is an integer that is a whole number.

9. The radio frequency amplifier according to claim 7, wherein each of said plurality of active element groups comprises 2n FETs, where n is an integer that is a whole number.

10. The radio frequency amplifier according to claim 2, wherein said FETs comprising said one or more active elements are located symmetrically with respect to a direction of propagation of said signal along said single input terminal.

11. The radio frequency amplifier according to claim 3, wherein said FETs comprising said one or more active elements are located symmetrically with respect to a direction of propagation of said signal along said single input terminal.

12. The radio frequency amplifier according to claim 2, wherein said bias control means includes FET switches.

13. The radio frequency amplifier according to claim 3, wherein said bias control means includes FET switches.

14. 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.

15. 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.

16. 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.

17. 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.

18. 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.

19. 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.