Integrated Radio Frequency Front-end Circuit

• US 20110319042A1
• Filed: 09/03/2010
• Published: 12/29/2011
• Est. Priority Date: 06/23/2010
• Status: Active Grant

• Current Assignee: LTIMindtree Ltd. (Larsen & Toubro Limited)
• Original Assignee: Mindtree Limited (Larsen & Toubro Limited)
• Inventors: Soman, Manoj Shridhar
• Granted Patent: US 8,787,964 B2
• Time in Patent Office: Days
• US Class Current: 455/205
• CPC Class Codes: H03F 3/45188 Non-folded cascode stages
• CPC Class Codes: H04B 1/18 Input circuits, e.g. for coupling to an antenna or a transmission line coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H
• CPC Class Codes: H04B 1/40 Circuits

Abstract

An integrated RF front-end circuit comprising a balun, a receiver amplifier, a power amplifier, and a selector circuit is provided. The balun comprises a center-tapped inductor having a first node, a center-tap switchlessly coupled to a fixed voltage, and a second node. The balun receives a single-ended signal through the first node to produce a differential signal at the first and second nodes. The differential signal is provided to balanced input lines of the receiver amplifier. Balanced output lines of the power amplifier provide a differential signal to the first and second nodes. The balun converts the differential signal to a single-ended signal. The single-ended signal is available at the first node of the center-tapped inductor. The selector circuit activates the receiver amplifier and deactivates the power amplifier, and vice versa. The power amplifier may comprise only a single-ended output line connected to either the first or the second node.

Claims

1. A radio frequency front-end circuit, comprising:

a balun, comprising;

a center-tapped inductor having a first node, a center-tap switchlessly coupled to a fixed voltage, and a second node, wherein said balun receives a single-ended signal through said first node of said center-tapped inductor and converts said single-ended signal to a differential signal, wherein said balun receives said differential signal through said first node and said second node and converts said differential signal to said single-ended signal, and wherein said differential signal is available at said first node and said second node, and said single-ended signal is available at said first node;

a receiver radio frequency amplifier having balanced input lines connected to said first node and said second node for reception and amplification of said differential signal, wherein said receiver radio frequency amplifier comprises one or more active components;

a radio frequency power amplifier having balanced output lines connected to said first node and said second node for providing an amplified differential signal to said balun, wherein said radio frequency power amplifier comprises one or more active components; and

a selector circuit in communication with said receiver radio frequency amplifier and said radio frequency power amplifier for activating said active components of said receiver radio frequency amplifier and deactivating said active components of said radio frequency power amplifier during said conversion of said single-ended signal to said differential signal, and vice versa during said conversion of said differential signal to said single-ended signal;

whereby said balun is switchlessly and selectively coupled to said receiver radio frequency amplifier during said conversion of said single-ended signal to said differential signal and said radio frequency power amplifier during said conversion of said differential signal to said single-ended signal.

2. The radio frequency front-end circuit of claim 1, wherein said fixed voltage is a supply ground.

3. The radio frequency front-end circuit of claim 1, wherein said fixed voltage is a supply voltage.

4. The radio frequency front-end circuit of claim 1, wherein said active components of said receiver radio frequency amplifier comprise one or more transistors, and wherein said selector circuit switches on said one or more transistors during said conversion of said single-ended signal to said differential signal.

5. The radio frequency front-end circuit of claim 1, wherein said active components of said radio frequency power amplifier comprise one or more transistors, and wherein said selector circuit switches on said one or more transistors during said conversion of said differential signal to said single-ended signal.

6. The radio frequency front-end circuit of claim 1, further comprising an antenna coupled to one of said first node and said second node of said center-tapped inductor.

7. The radio frequency front-end circuit of claim 6, wherein impedance of said antenna approximately matches input impedance of said receiver radio frequency amplifier.

8. The radio frequency front-end circuit of claim 6, wherein impedance of said antenna approximately matches output impedance of said radio frequency power amplifier.

9. The radio frequency front-end circuit of claim 6, wherein impedance of said antenna is Rin and impedance of each of said balanced input lines of said receiver radio frequency amplifier is 2Rin.

10. The radio frequency front-end circuit of claim 6, wherein impedance of said antenna is R_L and impedance of each of said balanced output lines of said radio frequency power amplifier is 2R_L.

11. The radio frequency front-end circuit of claim 1, further comprising a programmable logic circuit for programming said selector circuit for activating said active components of said receiver radio frequency amplifier and deactivating said active components of said radio frequency power amplifier during said conversion of said single-ended signal to said differential signal, and vice versa during said conversion of said differential signal to said single-ended signal.

12. A radio frequency front-end circuit, comprising:

a balun, comprising;

a center-tapped inductor having a first node, a center-tap switchlessly coupled to a fixed voltage, and a second node, wherein said balun receives said single-ended signal through said first node of said center-tapped inductor and converts said single-ended signal to a differential signal, wherein said balun receives said differential signal through said first node and said second node and converts said differential signal to said single-ended signal, and wherein said differential signal is available at said first node and said second node, and said single-ended signal is available at said first node;

a receiver radio frequency amplifier having balanced input lines connected to said first node and said second node for reception and amplification of said differential signal, wherein said receiver radio frequency amplifier comprises one or more active components;

a radio frequency power amplifier having a single-ended output line connected to one of said first node and said second node for providing an amplified single-ended signal for transmission, wherein said radio frequency power amplifier comprises one or more active components; and

a selector circuit in communication with said receiver radio frequency amplifier and said radio frequency power amplifier for activating said active components of said receiver radio frequency amplifier and deactivating said active components of said radio frequency power amplifier during said conversion of said single-ended signal to said differential signal, and vice versa during said conversion of said differential signal to said single-ended signal;

whereby said balun is switchlessly and selectively coupled to said receiver radio frequency amplifier during said conversion of said single-ended signal to said differential signal and said radio frequency power amplifier during said conversion of said differential signal to said single-ended signal.

13. The radio frequency front-end circuit of claim 12, wherein said fixed voltage is a supply ground.

14. The radio frequency front-end circuit of claim 12, wherein said fixed voltage is a supply voltage.

15. The radio frequency front-end circuit of claim 12, further comprising an antenna coupled to one of said first node and said second node of said center-tapped inductor.

16. The radio frequency front-end circuit of claim 15, wherein impedance of said antenna approximately matches input impedance of said receiver radio frequency amplifier.

17. The radio frequency front-end circuit of claim 12, further comprising a programmable logic circuit for programming said selector circuit for activating said active components of said receiver radio frequency amplifier and deactivating said active components of said radio frequency power amplifier during said conversion of said single-ended signal to said differential signal, and vice versa during said conversion of said differential signal to said single-ended signal.

18. A method of selectively accessing a balun in a radio frequency front-end circuit, comprising:

providing said balun comprising a center-tapped inductor and switchlessly coupling a center-tap of said center-tapped inductor to a fixed voltage;

providing a receiver radio frequency amplifier and a radio frequency power amplifier, wherein said receiver radio frequency amplifier and said radio frequency power amplifier comprise active components;

coupling a first node and a second node of said center-tapped inductor to balanced input lines of said receiver radio frequency amplifier and balanced output lines of said radio frequency power amplifier; and

switchlessly coupling one of said receiver radio frequency amplifier and said radio frequency power amplifier to said center-tapped inductor of said balun by performing one of;

activating active components of said receiver radio frequency amplifier and converting a single-ended signal received at one of said first node and said second node to a differential signal, wherein said differential signal is obtained at said first node and said second node, and wherein said differential signal is provided to said balanced input lines of said receiver radio frequency amplifier; and

activating active components of said radio frequency power amplifier and constructively combining an amplified differential signal along said first node and said second node for obtaining a single-ended signal at said first node, wherein said amplified differential signal is received from said radio frequency power amplifier through said balanced output lines.

19. The method of claim 18, wherein said fixed voltage is a supply ground.

20. The method of claim 18, wherein said fixed voltage is a supply voltage.

21. The method of claim 18, wherein said step of activating active components of said receiver radio frequency amplifier comprises deactivating said active components of said radio frequency power amplifier.

22. The method of claim 18, wherein said step of activating active components of said radio frequency power amplifier comprises deactivating said active components of said receiver radio frequency amplifier.

23. A method of selectively accessing a balun in a radio frequency front-end circuit, comprising:

providing said balun comprising a center-tapped inductor and switchlessly coupling a center-tap of said center-tapped inductor to a fixed voltage;

providing a receiver radio frequency amplifier and a radio frequency power amplifier, wherein said receiver radio frequency amplifier and said radio frequency power amplifier comprise active components;

coupling a first node and a second node of said center-tapped inductor to balanced input lines of said receiver radio frequency amplifier;

coupling one of said first node and said second node to a single-ended output line of said radio frequency power amplifier; and

switchlessly coupling one of said receiver radio frequency amplifier and said radio frequency power amplifier to said center-tapped inductor of said balun by performing one of;

activating active components of said receiver radio frequency amplifier and converting a single-ended signal received at one of said first node and said second node to a differential signal, wherein said differential signal is obtained at said first node and said second node, and wherein said differential signal is provided to said balanced input lines of said receiver radio frequency amplifier; and

activating active components of said radio frequency power amplifier and providing an amplified single-ended signal to one of said first node and said second node, wherein said amplified single-ended signal is received from said radio frequency power amplifier through said single-ended output line.

24. The method of claim 23, wherein said fixed voltage is a supply ground.

25. The method of claim 23, wherein said fixed voltage is a supply voltage.

26. The method of claim 23, wherein said step of activating active components of said receiver radio frequency amplifier comprises deactivating said active components of said radio frequency power amplifier.

27. The method of claim 23, wherein said step of activating active components of said radio frequency power amplifier comprises deactivating said active components of said receiver radio frequency amplifier.

28. A method of manufacturing a radio frequency front-end circuit, comprising:

integrating on a single semiconductor integrated circuit chip;

a balun comprising a center-tapped inductor having a first node, a second node, and a center-tap coupled to a fixed voltage;

a receiver radio frequency amplifier having balanced input lines coupled to said first node and said second node of said center-tapped inductor;

a radio frequency power amplifier having balanced output lines coupled to said first node and said second node of said center-tapped inductor; and

a selector circuit for selectively activating active components of said receiver radio frequency amplifier and deactivating active components of said radio frequency power amplifier, and vice versa.

29. The method of claim 28, wherein coupling said center-tap to said fixed voltage comprises coupling said fixed voltage to a supply ground.

30. The method of claim 28, wherein coupling said center-tap to said fixed voltage comprises coupling said fixed voltage to a supply voltage.

31. The method of claim 28, further comprising integrating on said single semiconductor integrated chip, a receiving module coupled to outputs of said receiver radio frequency amplifier.

32. The method of claim 28, further comprising integrating on said single semiconductor integrated chip, a transmitter module coupled to inputs of said radio frequency power amplifier.

33. The method of claim 28, further comprising integrating on said single semiconductor integrated chip, a programmable logic circuit for programming said selector circuit to selectively operate one of said receiver radio frequency amplifier and said radio frequency power amplifier.

34. A method of manufacturing a radio frequency front-end circuit, comprising:

integrating on a single semiconductor integrated circuit chip;

a balun comprising a center-tapped inductor having a first node, a second node, and a center-tap coupled to a supply voltage;

a receiver radio frequency amplifier having balanced input lines coupled to said first node and said second node of said center-tapped inductor;

a radio frequency power amplifier having a single-ended output line coupled to said first node of said center-tapped inductor; and

a selector circuit for selectively activating active components of said receiver radio frequency amplifier and deactivating active components of said radio frequency power amplifier, and vice versa.

35. The method of claim 34, wherein coupling said center-tap to said fixed voltage comprises coupling said fixed voltage to a supply ground.

36. The method of claim 34, wherein coupling said center-tap to said fixed voltage comprises coupling said fixed voltage to a supply voltage.

37. The method of claim 34, further comprising integrating on said single semiconductor integrated chip, a programmable logic circuit for programming said selector circuit to selectively operate one of said receiver radio frequency amplifier and said radio frequency power amplifier.