High frequency switch, amplifying circuit, and mobile communication terminal

• US 6,853,235 B2
• Filed: 04/15/2003
• Issued: 02/08/2005
• Est. Priority Date: 04/26/2002
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Nakayama, Masao, Yamamoto, Takashi, Motoyoshi, Kaname, Inamori, Masahiko
• Primary Examiner(s): Callahan, Timothy P.
• Assistant Examiner(s): Luu, An T.
• Application Number:
  US10/413,552
• Publication Number:
  US 20030201826A1
• Time in Patent Office: 665 Days
• Field of Search: 327/379, 327/389, 327/391, 327/401, 327/403, 327/404, 327/415, 327/416, 327/419, 327/427, 327/434, 327/436, 327/437, 333/100, 333/101, 333/103, 333/81.R
• US Class Current: 327/379
• CPC Class Codes: H03F 1/56 Modifications of input or output impedances, not otherwise provided for
• CPC Class Codes: H03F 2200/429 Two or more amplifiers or one amplifier with filters for different frequency bands are coupled in parallel at the input or output
• CPC Class Codes: H03F 3/72 Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal
• CPC Class Codes: H03K 17/693 Switching arrangements with several input- or output-terminals, e.g. multiplexers, distributors logic circuits H03K19/00; code converters H03M5/00, H03M7/00

Abstract

In order to provide a high frequency switch in which the setting range of the control voltage is expanded, the high frequency switch is constructed from a switch and a reference voltage generation circuit. The switch comprises first and second field effect transistors. In the first field effect transistor, the source electrode is connected to a signal input terminal, while the drain electrode is connected to a signal output terminal, and while the source electrode is connected to a control terminal. In the second field effect transistor, the source electrode is connected to the signal input terminal, while the drain electrode is connected to the signal output terminal, and while the gate electrode is connected to the control terminal. The reference voltage generation circuit generates two reference voltages the values of which are different from each other, then provides the lower reference voltage to the gate electrode of the first field effect transistor, and then provides the higher reference voltage to the source electrode of the second field effect transistor.

Claims

1. A high frequency switch comprising:

a signal input terminal;

first and second signal output terminals;

a control terminal to which a control voltage is applied;

a switch provided with;

(1) a first switch element having first and second signal electrodes and a first control electrode, said signal input terminal being connected to the first signal electrode, said first signal output terminal being connected to the second signal electrode, and said control terminal being connected to any one of the first and second signal electrodes, and (2) a second switch element having third and fourth signal electrodes and a second control electrode, said signal input terminal being connected to the third signal electrode, said second signal output terminal being connected to the fourth signal electrode, and said control terminal being connected to the second control electrode; and

a reference voltage generation circuit that generates first and second reference voltages, the values of which are different from each other, provides said first reference voltage to the first control electrode, and provides said second reference voltage to any one of the third and fourth signal electrodes of said second switch element, wherein;

on the basis of the relation between said control voltage and said first reference voltage and the relation between said control voltage and said second reference voltage, depending on the value of the control voltage, said first and second switch elements are selectively made conductive,

said first switch element is composed of a first field effect transistor in which any one of the source electrode and the drain electrode serves as said first signal electrode, the other one of the source electrode and the drain electrode serves as said second signal electrode, and the gate electrode serves as said first control electrode,

said second switch element is composed of a second field effect transistor in which any one of the source electrode and the drain electrode serves as said third signal electrode, the other one of the source electrode and the drain electrode serves as said fourth signal electrode, and the gate electrode serves as said second control electrode, and

the difference between said first reference voltage and said second reference voltage equals approximately to the threshold value of said first and second field effect transistors.

2. A high frequency switch according to claim 1, wherein said second reference voltage is higher than said first reference voltage.

3. A high frequency switch according to claim 1, wherein said reference voltage generation circuit comprises a serial circuit of three or more resistors.

4. A high frequency switch according to claim 1, wherein:

the gate electrode of said first field effect transistor and an output terminal of said reference voltage generation circuit are interconnected through a first resistor; and

the gate electrode of said second field effect transistor and said control terminal are connected through a second resistor.

5. An amplifying circuit comprising:

a signal input terminal;

first and second signal output terminals;

a control terminal to which a control voltage is applied;

a switch provided with;

(1) a first switch element having first and second signal electrodes and a first control electrode, said signal input terminal being connected to the first signal electrode and said control terminal being connected to any one of the first and second signal electrodes and (2) a second switch element having third and fourth signal electrodes and a second control electrode, said signal input terminal being connected to the third signal electrode and said control terminal being connected to the second control electrode;

a first amplifier having an input terminal connected to the second signal electrode and an output terminal connected to said first signal output terminal;

a second amplifier having an input terminal connected to the fourth signal electrode and an output terminal connected to said second signal output terminal; and

a reference voltage generation circuit that generates first and second reference voltages, provides said first reference voltage to the first control electrode, and provides said second reference voltage to any one of the third and fourth signal electrodes of said second switch element, wherein;

on the basis of the relation between said control voltage and said first reference voltage and the relation between said control voltage and said second reference voltage, depending on the value of the control voltage, said first and second switch elements are selectively made conductive,

when said first switch element is conductive, said first amplifier is made active while said second amplifier is made inactive;

when said second switch element is conductive, said first amplifier is made inactive while said second amplifier is made active,

said first switch element is composed of a first field effect transistor in which any one of the source electrode and the drain electrode serves as said first signal electrode, the other one of the source electrode and the drain electrode serves as said second signal electrode, and the gate electrode serves as said first control electrode,

said second switch element is composed of a second field effect transistor in which any one of the source electrode and the drain electrode serves as said third signal electrode, the other one of the source electrode and the drain electrode serves as said fourth signal electrode, and the gate electrode serves as said second control electrode,

said first amplifier is composed of a third field effect transistor or a first bipolar transistor in which the gate electrode or the base electrode serves as the input terminal of the first amplifier, the drain electrode or the collector electrode serves as the output terminal of the first amplifier, and the source electrode or the emitter electrode is grounded in the sense of high frequency, and

said second amplifier is composed of a fourth field effect transistor or a second bipolar transistor in which the gate electrode or the base electrode serves as the input terminal of the second amplifier, the drain electrode or the collector electrode serves as the output terminal of the second amplifier, and the source electrode or the emitter electrode is grounded in the sense of high frequency.

6. An amplifying circuit according to claim 5, wherein said second reference voltage is higher than said first reference voltage.

7. An amplifying circuit according to claim 5, wherein the difference between said first reference voltage and said second reference voltage equals approximately to the threshold value of said first and second field effect transistors.

8. An amplifying circuit according to claim 5, wherein said reference voltage generation circuit comprises a serial circuit of three or more resistors.

9. An amplifying circuit according to claim 5, wherein said control terminal and any one of the power supply terminals of said first and second amplifiers are connected in common.

10. An amplifying circuit according to claim 5, further comprising:

a third amplifier an output terminal of which is connected to said signal input terminal, wherein;

a signal inputted to an input terminal of said third amplifier is amplified and then provided to said signal input terminal, and

a power supply terminal of said third amplifier is connected in common with a power supply terminal of said reference voltage generation circuit.

11. An amplifying circuit comprising:

a signal input terminal;

first and second signal output terminals;

a control terminal to which a control voltage is applied;

a switch provided with;

(1) a first switch element having first and second signal electrodes and a first control electrode, said signal input terminal being connected to the first signal electrode, said first signal output terminal being connected to the second signal electrode, and said control terminal being connected to any one of the first and second signal electrodes and (2) a second switch element having third and fourth signal electrodes and a second control electrode, said signal input terminal being connected to the third signal electrode, said second signal output terminal being connected to the fourth signal electrode, and said control terminal being connected to the second control electrode;

a reference voltage generation circuit for generating first and second reference voltages the values of which are different from each other, providing said first reference voltage to the first control electrode of said first switch element, and providing said second reference voltage to any one of the third and the fourth signal electrodes of said second switch element; and

an amplifier an output terminal of which is connected to said signal input terminal;

wherein;

on the basis of the relation between said control voltage and said first reference voltage and the relation between said control voltage and said second reference voltage, depending on the value of the control voltage, said first and second switch elements are selectively made conductive,

a signal inputted to an input terminal of said amplifier is amplified and then provided to said signal input terminal; and

a power supply terminal of said amplifier is connected in common with a power supply terminal of said reference voltage generation circuit.

12. A mobile communication terminal comprising a high frequency switch having the function of selecting the path of a high frequency signal, said high frequency switch comprising:

a signal input terminal;

first and second signal output terminals;

a control terminal to which a control voltage is applied;

a switch provided with;

(1) a first switch element having first and second signal electrodes and a first control electrode, said signal input terminal being connected to the first signal electrode, said first signal output terminal being connected to the second signal electrode, and said control terminal being connected to any one of the first and second signal electrodes and (2) a second switch element having third and fourth signal electrodes and a second control electrode, said signal input terminal being connected to the third signal electrode, said second signal output terminal being connected to the fourth signal electrode, and said control terminal being connected to the second control electrode; and

a reference voltage generation circuit for generating first and second reference voltages the values of which are different from each other, providing said first reference voltage to the first control electrode of said first switch element, and providing said second reference voltage to any one of the third and fourth signal electrodes of said second switch element;

wherein;

on the basis of the relation between said control voltage and said first reference voltage and the relation between said control voltage and said second reference voltage, depending on the value of the control voltage, said first and second switch elements are selectively made conductive,

said first switch element is composed of a first field effect transistor in which any one of the source electrode and the drain electrode serves as said first signal electrode, the other one of the source electrode and the drain electrode serves as said second signal electrode, and the gate electrode serves as said first control electrode,

said second switch element is composed of a second field effect transistor in which any one of the source electrode and the drain electrode serves as said third signal electrode, the other one of the source electrode and the drain electrode serves as said fourth signal electrode, and the gate electrode serves as said second control electrode, and

the difference between said first reference voltage and said second reference voltage equals approximately to the threshold value of said first and second field effect transistors.

13. A mobile communication terminal comprising an amplifying circuit having the function of selecting the path of a high frequency signal, said amplifying circuit comprising:

a signal input terminal;

first and second signal output terminals;

a control terminal to which a control voltage is applied;

a switch provided with;

(1) a first switch element having first and second signal electrodes and a first control electrode, said signal input terminal being connected to the first signal electrode, and said control terminal being connected to any one of the first and second signal electrodes and (2) a second switch element having third and fourth signal electrodes and a second control electrode, said signal input terminal being connected to the third signal electrode, and said control terminal being connected to the second control electrode;

a first amplifier having an input terminal connected to the second signal electrode of said first switch element and an output terminal connected to said first signal output terminal;

a second amplifier having an input terminal connected to the fourth signal electrode of said second switch element and an output terminal connected to said second signal output terminal; and

a reference voltage generation circuit for generating first and second reference voltages, providing said first reference voltage to the first control electrode of said first switch element, and providing said second reference voltage to any one of the third and fourth signal electrodes of said second switch element;

wherein;

on the basis of the relation between said control voltage and said first reference voltage and the relation between said control voltage and said second reference voltage, depending on the value of the control voltage, said first and second switch elements are selectively made conductive,

when said first switch element is conductive, said first amplifier is made active while said second amplifier is made inactive; and

when said second switch element is conductive, said first amplifier is made inactive while said second amplifier is made active,

said first switch element is composed of a first field effect transistor in which any one of the source electrode and the drain electrode serves as said first signal electrode, the other one of the source electrode and the drain electrode serves as said second signal electrode, and the gate electrode serves as said first control electrode,

said second switch element is composed of a second field effect transistor in which any one of the source electrode and the drain electrode serves as said third signal electrode, the other one of the source electrode and the drain electrode serves as said fourth signal electrode, and the gate electrode serves as said second control electrode,

said first amplifier is composed of a third field effect transistor or a first bipolar transistor in which the gate electrode or the base electrode serves as the input terminal of the first amplifier, the drain electrode or the collector electrode serves as the output terminal of the first amplifier, and the source electrode or the emitter electrode is grounded in the sense of high frequency, and

said second amplifier is composed of a fourth field effect transistor or a second bipolar transistor in which the gate electrode or the base electrode serves as the input terminal of the second amplifier, the drain electrode or the collector electrode serves as the output terminal of the second amplifier, and the source electrode or the emitter electrode is grounded in the sense of high frequency.

14. A mobile communication terminal comprising an amplifying circuit having the function of selecting the path of a high frequency signal,

said amplifying circuit comprising:

a signal input terminal;

first and second signal output terminals;

a control terminal to which a control voltage is applied;

a switch provided with;

(1) a first switch element having first and second signal electrodes and a first control electrode, said signal input terminal being connected to the first signal electrode, said first signal output terminal being connected to the second signal electrode, and said control terminal being connected to any one of the first and second signal electrodes and (2) a second switch element having third and fourth signal electrodes and a second control electrode, said signal input terminal being connected to the third signal electrode, said second signal output terminal being connected to the fourth signal electrode, and said control terminal being connected to the second control electrode;

a reference voltage generation circuit for generating first and second reference voltages the values of which are different from each other, providing said first reference voltage to the first control electrode of said first switch element, and providing said second reference voltage to any one of the third and fourth signal electrodes of said second switch element; and

an amplifier an output terminal of which is connected to said signal input terminal;

wherein;

on the basis of the relation between said control voltage and said first reference voltage and the relation between said control voltage and said second reference voltage, depending on the value of the control voltage, said first and second switch elements are selectively made conductive,

a signal inputted to an input terminal of said amplifier is amplified and then provided to said signal input terminal; and

a power supply terminal of said amplifier is connected in common with a power supply terminal of said reference voltage generation circuit.