HIGH FREQUENCY SWITCHING CIRCUIT

• US 20080258799A1
• Filed: 04/09/2008
• Published: 10/23/2008
• Est. Priority Date: 04/17/2007
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Teraguchi, Takayuki, Kawakyu, Katsue
• Granted Patent: US 7,659,770 B2
• Time in Patent Office: Days
• US Class Current: 327/427
• CPC Class Codes: H03K 17/005 with several inputs only
• CPC Class Codes: H03K 17/161 in field-effect transistor switches
• CPC Class Codes: H03K 17/302 in field-effect transistor switches
• CPC Class Codes: H03K 17/6871 the output circuit comprising more than one controlled field-effect transistor
• 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
• CPC Class Codes: H03K 2217/0018 Special modifications or use of the back gate voltage of a FET

Abstract

A high frequency switching circuit is disclosed. The high frequency switching circuit is provided with first and second high frequency signal terminals, a control terminal, a field-effect transistor having a drain, a source and a gate. The field-effect transistor is connected between the first and the second high frequency signal terminals so as to switch a high frequency signal. The high frequency switching circuit is further provided with a variable resistance circuit which is connected between the gate of the field-effect transistor and the control terminal.

Claims

1. A high frequency switching circuit comprising:

first and second high frequency signal terminals;

a first control terminal;

a first field-effect transistor having a drain, a source and a gate, the first field-effect transistor being connected between the first and the second high frequency signal terminals to switch higher frequency signals; and

a variable resistance circuit connected between the gate of the first field-effect transistor and the first control terminal.

2. The high frequency switching circuit according to claim 1, wherein the first variable resistance circuit is provided with a resistance and a field-effect transistor connected in parallel with each other.

3. The high frequency switching circuit according to claim 1, wherein the first variable resistance circuit is provided with a normally-on type field-effect transistor.

4. The high frequency switching circuit according to claim 1, wherein the first field-effect transistor has a back gate to which a second variable resistance circuit is connected.

5. The high frequency switching circuit according to claim 1, further comprising a second field-effect transistor having a drain, a source and a gate, the second field-effect transistor being connected between one of the drain and the source and a power supply terminal.

6. The high frequency switching circuit according to claim 5, further comprising a second control terminal and a variable resistance circuit connected between the second control terminal and the gate of the second field-effect transistor.

7. The high frequency switching circuit according to claim 6, wherein the second field-effect transistor has a back gate to which a variable resistance circuit is connected.

8. A high frequency switching circuit comprising:

first and second high frequency signal terminals;

a power supply terminal;

a first control terminal;

a first field-effect transistor having a drain, a source and a gate, the first field-effect transistor being connected between the first and the second high frequency signal terminals to switch a higher frequency signal;

a second field-effect transistor having a drain, a source and a gate, the first field-effect transistor being connected between the first and the second high frequency signal terminals; and

a variable resistance circuit connected between the gate of the second field-effect transistor and the second control terminal.

9. The high frequency switching circuit according to claim 8, wherein the variable resistance circuit is provided with a resistance and a field-effect transistor connected in parallel with each other.

10. The high frequency switching circuit according to claim 8, wherein the variable resistance circuit is provided with a normally-on type field-effect transistor.

11. The high frequency switching circuit according to claim 8, wherein the second field-effect transistor has a back gate to which a variable resistance circuit is connected.

12. The high frequency switching circuit according to claim 11, further comprising a variable resistance circuit, the variable resistance being connected between the gate of the first field-effect transistor and the first control terminal.

13. A high frequency switching circuit comprising:

a pair of first high frequency signal terminals;

a second high frequency signal terminal serving as a common high frequency signal terminal;

first and second control terminals;

a pair of first field-effect transistors respectively having a drain, a source and a gate, the first field-effect transistors being respectively connected between the first high frequency signal terminals and the second high frequency signal terminal to switch first and second high frequency signal; and

a pair of first variable resistance circuits connected between the gates of the first field-effect transistors and the first and second control terminals respectively.

14. The high frequency switching circuit according to claim 13, wherein the first variable resistance circuit is provided with is provided with a resistance and a field-effect transistor connected in parallel with each other.

15. The high frequency switching circuit according to claim 13, wherein the first variable resistance circuit is provided with a normally-on type field-effect transistor.

16. The high frequency switching circuit according to claim 13, wherein the first field-effect transistors have a back gate to which a second variable resistance circuit is connected.

17. The high frequency switching circuit according to claim 13, further comprising a pair of second field-effect transistors having drains, sources and gates respectively, the second field-effect transistors being respectively connected between the first high frequency signal terminals and a power supply terminal, and the gates being connected to the second and the first control terminals respectively.

18. The high frequency switching circuit according to claim 17, further comprising a pair of third variable resistance circuits, third variable resistance circuits being connected between the gates of the second field-effect transistors and the second and the first control terminals respectively.

19. The high frequency switching circuit according to claim 18, wherein the first field-effect transistors have back gates respectively and a pair of fourth variable resistance circuits are connected between the back gates and a power supply terminal.

20. The high frequency switching circuit according to claim 19, wherein the first and second field-effect transistors are N-channel type and the field-effect transistors constituting the fourth variable resistance circuits are P-channel type.