Radio-frequency switch circuit

• US 8,320,843 B2
• Filed: 03/28/2012
• Issued: 11/27/2012
• Est. Priority Date: 09/25/2008
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Seshita, Toshiki, Wakimoto, Hirotsugu
• Primary Examiner(s): HSIEH, PING Y
• Application Number:
  US13/432,610
• Publication Number:
  US 20120182061A1
• Time in Patent Office: 244 Days
• Field of Search: 455/78, 455/62, 455/63.1, 455/63.3, 455/82, 455/83, 455/191.3, 455/333, 455/114.1, 455/114.2, 455/278.1, 455/296, 455/277.1, 455/197.1, 330/149, 330/150, 333/103, 333/104, 333/101, 333/262, 327/408, 327/430, 327/435, 327/436, 327/416, 327/427
• US Class Current: 455/78
• 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 2217/0036 Means reducing energy consumption
• CPC Class Codes: H03K 2217/0054 Gating switches, e.g. pass gates
• CPC Class Codes: H04B 1/005 adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges
• CPC Class Codes: H04B 1/48 in circuits for connecting transmitter and receiver to a common transmission path, e.g. by energy of transmitter H04B1/46 takes precedence

Abstract

A radio-frequency switch circuit of the invention includes: n-stage through FETs (field effect transistors) connected in series between the antenna terminal and each of the radio-frequency terminals, where n is a natural number; a radio-frequency leakage prevention resistor connected to a gate of the through FETs; a control signal line commonly connected to the gates of the n-stage through FETs connected to the same radio-frequency terminal; and a resistor connected to each of at least two of the control signal lines and connected to the radio-frequency leakage prevention resistor in series The two control signal lines are capacitively coupled between the resistor and the through FETs.

Claims

1. A radio-frequency switch circuit comprising:

a first terminal;

two or more second terminals;

through FETs (field effect transistors) coupled in series between the first terminal and each of the second terminals;

a radio-frequency leakage prevention resistor coupled to a gate of a through FET that is coupled to one second terminal;

two control signal lines wired adjacently in parallel, comprising;

one control signal line coupled between the radio-frequency leakage prevention resistor that is coupled to the one second terminal and a control circuit that supplies a control signal to the through FETs, and

another control signal line that is coupled between the control circuit and another radio-frequency leakage prevention resistor that is coupled to a gate of another through FET that is coupled to another second terminal; and

a resistor inserted in each of the two control signal lines.

2. The switch circuit according to claim 1, wherein

shunt FETs are connected between each of the second terminals and the ground, and

a ground line, or a control signal line for the shunt FETs dedoupled so as to be equivalent to the ground line in terms of radio frequency, is wired on both sides of the two control signal lines.

3. The switch circuit according to claim 2, wherein when the through FETs connected to one of the second terminals are turned on, the shunt FETs connected to the same second terminal and the other through FETs connected to the other second terminals are turned off, and the other shunt FETs connected to the other second terminals are turned on.

4. The switch circuit according to claim 2, wherein the through FET, the radio-frequency leakage prevention resistor, the control signal line, the resistor, and the shunt FET are formed on a single semiconductor substrate.

5. The switch circuit according to claim 1, wherein the two control signal lines is capacitively coupled via a MIM (metal-insulator-metal) structure.

6. The switch circuit according to claim 1, wherein the control signal lines are laid out so that wiring lengths from the resistors to the through FETs connected to the resistors are generally equal.

7. The switch circuit according to claim 1, wherein each of the control signal lines does not intersect other interconnects on which a radio-frequency signal is transmitted.

8. The switch circuit according to claim 1, wherein a radio-frequency signal having a phase difference with respect to a radio-frequency signal inputted from the second terminal is applied to the gate of the through FET in off-state connected to the another control signal line.

9. The switch circuit according to claim 8, wherein the phase difference is 60 degrees in a fundamental frequency.

10. The switch circuit according to claim 1, wherein

at least one of the second terminals is connected to a UMTS (Universal Mobile Telecommunications System) transceiver circuit, and

the resistor is inserted in the control signal line corresponding to a second terminal connected to a UMTS transceiver circuit.

11. A radio-frequency switch circuit comprising:

a first terminal;

two or more second terminals;

through FETs (field effect transistors) coupled in series between the first terminal and each of the second terminals;

a radio-frequency leakage prevention resistor connected coupled to a gate of a through FET that is coupled to one second terminal;

two control signal lines wired adjacently in parallel, comprising;

one control signal line that is coupled to the radio-frequency leakage prevention resistor that is coupled to the one second terminal, and

another control signal line that is coupled to another radio-frequency leakage prevention resistor that is coupled to a gate of another through FET that is coupled to another second terminal;

a driver coupled to each of the two control signal lines; and

at least one resistor coupled to at least one of the two control-signal lines and configured to be a resistance of an output of the driver.

12. A radio-frequency switch circuit comprising:

a first terminal;

two or more second terminals;

through FETs (field effect transistors) coupled in series between the first terminal and each of the second terminals;

a through FET radio-frequency leakage prevention resistor coupled to a gate of a through FET of the through FETs;

a through FET control signal line coupled between the through FET radio-frequency leakage prevention resistor and a control circuit supplying a control signal to the through FETs;

a through FET resistor inserted in the through FET control signal line;

shunt FETs coupled in series between each of the second terminals and the ground;

a shunt FET radio-frequency leakage prevention resistor coupled to a gate of the shunt FETs;

a shunt FET control signal line coupled between the shunt FET radio-frequency leakage prevention resistor and the control circuit supplying a control signal to the shunt FETs; and

a shunt FET resistor inserted in the shunt FET control signal line,

the through FET control signal line between the through FET resistor and the through FET radio-frequency leakage prevention resistor, and the shunt FET control signal line between the shunt FET resistor and the shunt FET radio-frequency leakage prevention resistor being wired adjacently in parallel.

13. The switch circuit according to claim 12, wherein the through FET control signal line and the shunt FET control signal line wired adjacently in parallel is capacitively coupled via a MIM (metal-insulator-metal) structure.

14. The switch circuit according to claim 12, wherein the through FET control signal line and the shunt FET control signal line do not intersect other interconnects on which a radio-frequency signal is transmitted.

15. The switch circuit according to claim 12, wherein a radio-frequency signal having a phase difference with respect to a radio-frequency signal inputted from the second terminal is applied to gates of the shunt FETs in off-state via the shunt FET control signal line wired adjacently in parallel to the through FET control signal line connected to the gates of the through FETs in on-state connected to the second terminal.

16. The switch circuit according to claim 15, wherein the phase difference is 60 degrees in a fundamental frequency.

17. The switch circuit according to claim 12, wherein the second terminal is connected to a UMTS (Universal Mobile Telecommunications System) transceiver circuit, where the second terminal is connected to the through FETs and the shunt FETs connected, respectively, to the through FET control signal line and the shunt FET control signal line which are wired adjacently in parallel to each other.

18. The switch circuit according to claim 12, wherein when the through FETs connected to one of the second terminals are turned on, the shunt FET connected to the same second terminal and the other through FETs connected to the other second terminals are turned off, and the other shunt FETs connected to the other second terminals are turned on.

19. The switch circuit according to claim 12, wherein the through FET, the through FET radio-frequency leakage prevention resistor, the through FET control signal line, the through FET resistor, the shunt FET, the shunt FET radio-frequency leakage prevention resistor, the shunt FET control signal line, and the shunt FET resistor are formed on a single semiconductor substrate.