Apparatus and method for front-end circuitry in radio-frequency apparatus

• US 7,035,611 B2
• Filed: 02/19/2002
• Issued: 04/25/2006
• Est. Priority Date: 01/12/2001
• Status: Expired due to Term

• Current Assignee: Silicon Laboratories Incorporated
• Original Assignee: Silicon Laboratories Incorporated
• Inventors: Scott, Jeffrey W., Tuttle, G. Tyson, Behrens, Richard T., Kerth, Donald A., Srinivasan, Vishnu S., Garlepp, Eric R., Vishakhadatta, G. Diwakar
• Primary Examiner(s): Vuong, Quochien B.
• Assistant Examiner(s): PHU, SANH D
• Application Number:
  US10/079,057
• Publication Number:
  US 20030017809A1
• Time in Patent Office: 1,526 Days
• Field of Search: 455/209, 455/323, 455/313, 455/333, 455/339, 455/269, 455/307, 343/702, 343/713, 343/703, 375/216, 333/124
• US Class Current: 455/269
• CPC Class Codes: H04B 1/0003 Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain digital baseband systems H04L25/00; digital modulation/demodulation H04L27/00; CDMA H04B1/707; TDMA H04B7/2643; image transmission H04N5/00
• CPC Class Codes: H04B 1/28 the receiver comprising at least one semiconductor device having three or more electrodes
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes
• CPC Class Codes: H04B 15/02 Reducing interference from electric apparatus by means located at or near the interfering apparatus
• CPC Class Codes: H04B 15/04 the interference being caused by substantially sinusoidal oscillations, e.g. in a receiver or in a tape-recorder
• CPC Class Codes: H04B 2215/064 Reduction of clock or synthesizer reference frequency harmonics

Abstract

A radio-frequency (RF) apparatus includes front-end circuitry. The front-end circuitry includes a filter circuitry and an impedance matching circuitry. The filter circuitry has a differential output that has an output impedance. The filter circuitry filters signals outside a signal band of interest. The impedance matching network has a differential input coupled to the output of the filter circuitry. The impedance matching network also has a differential output coupled to a signal processing circuitry. The signal processing circuitry has an input impedance. The impedance matching network matches the input impedance of the signal processing circuitry to the output impedance of the filter circuitry.

Claims

1. A front-end circuitry in a radio-frequency (RF) apparatus, comprising:

a filter circuitry with a differential output, having an output impedance, the filter circuitry configured to filter signals outside a signal band of interest, the filter circuitry configured to receive and filter a radio-frequency (RF) signal; and

an impedance matching network, with a differential input coupled to the output of the filter circuitry the differential input having symmetrical impedances from input signal lines to a reference node, the impedance matching network further having a differential output coupled to a signal processing circuitry having an input impedance the differential output having symmetrical impedances from output signal lines to the reference node,

wherein the impedance matching network matches the input impedance of the signal processing circuitry to the output impedance of the filter circuitry.

2. The front-end circuitry according to claim 1, wherein the signal processing circuitry comprises an amplifier circuitry.

3. The front-end circuitry according to claim 2, wherein signal processing circuitry comprises a low-noise amplifier circuitry.

4. The front-end circuitry according to claim 3, wherein the impedance matching network comprises a differential L-network.

5. The front-end circuitry according to claim 4, wherein the signal processing circuitry comprises a single-ended output.

6. The front-end circuitry according to claim 4, wherein the signal processing circuitry comprises a differential output.

7. The front-end circuitry according to claim 4, wherein the differential L-network comprises two inductors and a capacitor.

8. The front-end circuitry according to claim 4, wherein the differential L-network comprises two capacitors and an inductor.

9. The front-end circuitry according to claim 3, wherein the impedance matching network comprises a plurality of differential L-networks.

10. The front-end circuitry according to claim 9, wherein the signal processing circuitry comprises a single-ended output.

11. The front-end circuitry according to claim 9, wherein the signal processing circuitry comprises a differential output.

12. The front-end circuitry according to claim 3, wherein the impedance matching network comprises a differential Π

-network.

13. The front-end circuitry according to claim 12, wherein the signal processing circuitry comprises a single-ended output.

14. The front-end circuitry according to claim 12, wherein the signal processing circuitry comprises a differential output.

15. The front-end circuitry according to claim 12, wherein the differential Π

-network comprises two inductors and two capacitors.

16. The front-end circuitry according to claim 3, wherein the impedance matching network comprises a plurality of differential Π

-networks.

17. The front-end circuitry according to claim 16, wherein the signal processing circuitry comprises a single-ended output.

18. The front-end circuitry according to claim 16, wherein the signal processing circuitry comprises a differential output.

19. The front-end circuitry according to claim 3, wherein the impedance matching network comprises a differential T-network.

20. The front-end circuitry according to claim 19, wherein the signal processing circuitry comprises a single-ended output.

21. The front-end circuitry according to claim 19, wherein the signal processing circuitry comprises a differential output.

22. The front-end circuitry according to claim 19, wherein the differential T-network comprises four inductors and one capacitor.

23. The front-end circuitry according to claim 19, wherein the differential T-network comprises four capacitors and one inductor.

24. The front-end circuitry according to claim 3, wherein the impedance matching network comprises a plurality of differential T-networks.

25. The front-end circuitry according to claim 24, wherein the signal processing circuitry comprises a single-ended output.

26. The front-end circuitry according to claim 24, wherein the signal processing circuitry comprises a differential output.

27. The front-end circuitry according to claim 3, wherein the impedance matching network comprises at least one of a differential L-network, a differential Π

-network, a differential T-network, or a combination thereof coupled in cascade.

28. The front-end circuitry according to claim 27, wherein the signal processing circuitry comprises a single-ended output.

29. The front-end circuitry according to claim 27, wherein the signal processing circuitry comprises a differential output.

30. The front-end circuitry according to claim 3, wherein the impedance matching network comprises a differential transmission line.

31. The front-end circuitry according to claim 30, wherein the signal processing circuitry comprises a single-ended output.

32. The front-end circuitry according to claim 30, wherein the signal processing circuitry comprises a differential output.

33. A radio-frequency (RF) apparatus, comprising:

an impedance matching network, having a differential input having symmetrical impedances from input signal lines to a reference node, and a differential output having symmetrical impedances from output signal lines to the reference node; and

a filter configured to receive a radio-frequency input signal, the filter having a differential output configured to provide a filtered radio-frequency (RF) signal to the impedance matching network.

34. The radio-frequency apparatus of claim 33, further comprising a signal-processing circuit having a differential input, the signal-processing circuit configured to accept a signal from the differential output of the impedance matching network.

35. The radio-frequency apparatus of claim 34, wherein the impedance matching network matches an output impedance of the filter to an input impedance of the signal-processing circuit.

36. The radio-frequency apparatus of claim 35, wherein the impedance matching network comprises at least one differential L-network.

37. The radio-frequency apparatus of claim 36, wherein the signal-processing circuit comprises a low-noise amplifier.

38. The radio-frequency apparatus of claim 37, further comprising a first integrated circuit, wherein the low-noise amplifier resides within the first integrated circuit.

39. The radio-frequency apparatus of claim 38, wherein the first integrated circuit further comprises radio-frequency receiver circuitry.

40. The radio-frequency apparatus of claim 39, further comprising a second integrated comprising digital signal-processing circuitry, the second integrated circuit coupled to the first integrated circuit and configured to accept a digital output signal of the first integrated circuit.

41. The radio-frequency apparatus of claim 35, wherein the impedance matching network comprises at least one differential Π

-network.

42. The radio-frequency apparatus of claim 41, wherein the signal-processing circuit comprises a low-noise amplifier.

43. The radio-frequency apparatus of claim 42, further comprising a first integrated circuit, wherein the low-noise amplifier resides within the first integrated circuit.

44. The radio-frequency apparatus of claim 43, wherein the first integrated circuit further comprises radio-frequency receiver circuitry.

45. The radio-frequency apparatus of claim 44, further comprising a second integrated comprising digital signal-processing circuitry, the second integrated circuit coupled to the first integrated circuit and configured to accept a digital output signal of the first integrated circuit.

46. The radio-frequency apparatus of claim 35, wherein the impedance matching network comprises at least one differential T-network.

47. The radio-frequency apparatus of claim 46, wherein the signal-processing circuit comprises a low-noise amplifier.

48. The radio-frequency apparatus of claim 47, further comprising a first integrated circuit, wherein the low-noise amplifier resides within the first integrated circuit.

49. The radio-frequency apparatus of claim 48, wherein the first integrated circuit further comprises radio-frequency receiver circuitry.

50. The radio-frequency apparatus of claim 49, further comprising a second integrated comprising digital signal-processing circuitry, the second integrated circuit coupled to the first integrated circuit and configured to accept a digital output signal of the first integrated circuit.

51. The radio-frequency apparatus of claim 35, wherein the impedance matching network comprises a cascade coupling of at least one differential L-network, at least one differential Π

-network, at least one differential T-network, or a combination thereof.

52. The radio-frequency apparatus of claim 51, wherein the signal-processing circuit comprises a low-noise amplifier.

53. The radio-frequency apparatus of claim 52, further comprising a first integrated circuit, wherein the low-noise amplifier resides within the first integrated circuit.

54. The radio-frequency apparatus of claim 53, wherein the first integrated circuit further comprises radio-frequency receiver circuitry.

55. The radio-frequency apparatus of claim 54, further comprising a second integrated comprising digital signal-processing circuitry, the second integrated circuit coupled to the first integrated circuit and configured to accept a digital output signal of the first integrated circuit.

56. The radio-frequency apparatus of claim 35, wherein the impedance matching network comprises a differential transmission line.

57. The radio-frequency apparatus of claim 56, wherein the signal-processing circuit comprises a low-noise amplifier.

58. The radio-frequency apparatus of claim 57, further comprising a first integrated circuit, wherein the low-noise amplifier resides within the first integrated circuit.

59. The radio-frequency apparatus of claim 58, wherein the first integrated circuit further comprises radio-frequency receiver circuitry.

60. The radio-frequency apparatus of claim 59, further comprising a second integrated comprising digital signal-processing circuitry, the second integrated circuit coupled to the first integrated circuit and configured to accept a digital output signal of the first integrated circuit.

61. A method of processing signals in a radio-frequency (RF) apparatus, comprising:

filtering an input radio-frequency signal in a filter that has a differential output configured to provide a filtered radio-frequency (RF) signal; and

receiving and processing the filtered signal in an impedance matching network that has a differential input having symmetrical impedances from input signal lines to a reference node, the impedance matching network configured to generate an output signal at a differential output of the impedance matching network, the differential output having symmetrical impedances from output signal lines to a reference node.

62. The method of claim 61, wherein the impedance matching network is configured to match an output impedance of the filter to an input impedance of the signal-processing circuit.

63. The method of claim 62, further comprising processing the output signal in a radio-frequency receiver circuitry.

64. The method of claim 63, wherein processing the output signal in a radio-frequency receiver circuitry comprises processing the output signal in a low-noise amplifier.

65. The method of claim 64, wherein the impedance matching network for receiving and processing the filtered signal comprises at least one differential L-network.

66. The method of claim 64, wherein the impedance matching network for receiving and processing the filtered signal comprises at least one differential Π

-network.

67. The method of claim 64, wherein the impedance matching network for receiving and processing the filtered signal comprises at least one differential T-network.

68. The method of claim 64, wherein the impedance matching network for receiving and processing the filtered signal comprises a cascade coupling of at least one differential L-network, at least one differential Π

-network, at least one differential T-network, or a combination thereof.

69. The method of claim 64, wherein the impedance matching network for receiving and processing the filtered signal comprises a differential transmission line.

70. The method of claim 64, wherein the impedance matching network for receiving and processing the filtered signal comprises at least one of a differential L-network, a differential P-network, and a differential T-network.

71. The method of claim 70, wherein the low-noise amplifier for processing the output signal resides in a first integrated circuit that includes the radio-frequency receiver circuitry.

72. The method of claim 71, further comprising:

receiving in a second integrated circuit a digital output signal of the radio-frequency receiver circuitry; and

processing digitally the digital output signal of the radio-frequency receiver circuitry.