Circuit arrangement and method of operating a circuit arrangement

• US 8,331,388 B2
• Filed: 09/21/2007
• Issued: 12/11/2012
• Est. Priority Date: 09/29/2006
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Mobile Communications GmbH (Intel Corporation)
• Inventors: Kodim, Walter
• Primary Examiner(s): Wilson, Robert
• Assistant Examiner(s): Zhao, Wei
• Application Number:
  US11/859,184
• Publication Number:
  US 20080080404A1
• Time in Patent Office: 1,908 Days
• Field of Search: 370/419, 365/154
• US Class Current: 370/419
• CPC Class Codes: H04B 1/0458 Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages matching circuits in general H03H

Abstract

A circuit arrangement and a method of operating a circuit arrangement. The circuit arrangement includes an amplifier having an output port, a duplexer having an input port coupled to the output port of the amplifier and having a combined input/output port to couple to an antenna, and a switch configured to create an impedance load mismatch at the input port of the duplexer independent of the impedance of the output port of the amplifier by acting on a connecting line between the output port of the amplifier and the input port of the duplexer.

Claims

1. A circuit arrangement, comprising:

an amplifier having an output port;

a duplexer having an input port coupled to the output port of the amplifier and having a combined input/output port to be coupled to an antenna; and

a switch configured to create an impedance load mismatch at the input port of the duplexer, that is independent of the impedance of the output port of the amplifier by acting on a connecting line between the output port of the amplifier and the input port of the duplexer, thereby creating a reflective termination of the input port of the duplexer.

2. The circuit arrangement as recited in claim 1, wherein the switch is configured to create the impedance load mismatch by opening the connecting line.

3. The circuit arrangement as recited in claim 1, wherein the switch is configured to create the impedance load mismatch by grounding the connecting line.

4. The circuit arrangement as recited in claim 1, further comprising a circulator having a first port coupled to the output port of the amplifier, having a second port coupled to the input port of the duplexer, and having a third port coupled to a load resistor, the load resistor configured to match the impedance of an antenna to couple to the combined input/output port of the duplexer,

wherein the switch is configured to create the impedance load mismatch at the input port of the duplexer by acting on a connecting line between the second port of the circulator and the input port of the duplexer.

5. The circuit arrangement as recited in claim 1, wherein the amplifier is a power amplifier in a transmitter path of a wireless communication device.

6. The circuit arrangement as recited in claim 1, wherein the duplexer is a receive/transmit duplexer in a wireless communication device.

7. The circuit arrangement as recited in claim 1, configured to operate in an UMTS mobile phone.

8. The circuit arrangement as recited in claim 1, configured to operate in an UMTS portion of a dual mode UMTS/GSM mobile phone, the mobile phone comprising at least one dedicated antenna for each of the UMTS portion and a GSM portion.

9. A circuit arrangement comprising:

an amplifier having an output port;

a circulator having a first port coupled to the output port of the amplifier, having a second port to couple to an antenna, and having a third port coupled to a load resistor, the load resistor configured to match the impedance of an antenna to couple to the second port of the circulator; and

a switch configured to create an impedance load mismatch at the third port of the circulator, that is independent of the impedance of the load resistor by acting on a connecting line between the load resistor and the third port of the circulator, thereby creating a reflective termination of the third port of the circulator.

10. The circuit arrangement as recited in claim 9, wherein the switch is configured to create an impedance load mismatch by opening the connecting line.

11. The circuit arrangement as recited in claim 9, wherein the switch is configured to create an impedance load mismatch by grounding the connecting line.

12. The circuit arrangement as recited in claim 9, wherein the amplifier is configured, if it is in an active state, to match the impedance of an antenna to couple to the second port of the circulator, and, if it is in an idle state, to create an impedance load mismatch at the first port of the circulator.

13. The circuit arrangement as recited in claim 9, wherein the amplifier is a power amplifier in a transmitter path of a wireless communication device.

14. The circuit arrangement as recited in claim 9, configured to operate in an UMTS mobile phone.

15. The circuit arrangement as recited in claim 9, configured to operate in an UMTS portion of a dual mode UMTS/GSM mobile phone, the mobile phone comprising at least one dedicated antenna for each of the UMTS portion and a GSM portion.

16. The circuit arrangement as recited in claim 9, further comprising a duplexer having an input port coupled to the second port of the circulator and having a combined input/output port to couple to an antenna.

17. A method of operating a circuit arrangement, the method comprising:

having an amplifier, a duplexer and a switch,

if the amplifier is in an active state, applying a signal from an output port of the amplifier with matching impedance load to an input port of the duplexer; and

if the amplifier is in an idle state, creating an impedance load mismatch at the input port of the duplexer, that is independent of the impedance of the output port of the amplifier by switching the switch and thereby acting on a connecting line between the output port of the amplifier and the input port of the duplexer to create a reflective termination of the input port of the duplexer.

18. The method as recited in claim 17, wherein the connecting line between the output port of the amplifier and the input port of the duplexer is opened by switching the switch.

19. The method as recited in claim 17, wherein the connecting line between the output port of the amplifier and the input port of the duplexer is grounded by switching the switch.

20. A method of operating a dual mode UMTS/GSM mobile phone, the method comprising:

having at least one dedicated antenna for each of an UMTS portion and a GSM portion, having a power amplifier in a transmitter path of the UMTS portion and having a receive/transmit duplexer in the UMTS portion,

if the amplifier is in an active state, applying a signal from an output port of the amplifier with matching impedance load to an input port of the duplexer, and applying a signal from a combined input/output port of the duplexer to the dedicated UMTS antenna; and

if the amplifier is in an idle state, creating an impedance load mismatch at the input port of the duplexer, that is independent of the impedance of the output port of the amplifier by switching a switch and thereby acting on a connecting line between the output port of the amplifier and the input port of the duplexer to create a reflective termination of the input port of the duplexer.

21. The method as recited in claim 20, whereby the connecting line between the output port of the amplifier and the input port of the duplexer is opened by switching the switch.

22. The method as recited in claim 20, whereby the connecting line between the output port of the amplifier and the input port of the duplexer is grounded by switching the switch.

23. A method of operating a circuit arrangement, the method comprising:

having an amplifier, a circulator and a switch,

if the amplifier is in an active state, applying a signal from an output port of the amplifier to a first port of the circulator and through the circulator to a second port of the circulator, whereby the second port is configured to couple to an antenna and a third port of the circulator is coupled to a load resistor configured to match the impedance of an antenna to couple to the second port of the circulator; and

if the amplifier is in an idle state, creating an impedance load mismatch at the third port of the circulator, that is independent of the impedance of the load resistor by switching the switch and thereby acting on a connecting line between the load resistor and the third port of the circulator to create a reflective termination of the third port of the circulator.

24. The method as recited in claim 23, whereby the connecting line between the load resistor and the third port of the circulator is opened by switching the switch.

25. The method as recited in claim 23, whereby the connecting line between the load resistor and the third port of the circulator is grounded by switching the switch.