Diplexer circuit for wireless communication devices

• US 7,389,090 B1
• Filed: 10/25/2004
• Issued: 06/17/2008
• Est. Priority Date: 10/25/2004
• Status: Active Grant

• Current Assignee: Micro Mobio Corporation
• Original Assignee: Micro Mobio Incorporated
• Inventors: Ichitsubo, Ikuroh, Kubota, Kanya
• Primary Examiner(s): JACKSON, BLANE J
• Application Number:
  US10/972,636
• Time in Patent Office: 1,331 Days
• Field of Search: 455/562.6, 455/78, 455/132, 455/288, 455/286, 455/282, 455/281, 455/280, 455/82, 455/83, 455269-2791, 333/132, 333/135, 333/133
• US Class Current: 455/82
• CPC Class Codes: H03H 7/0123 comprising distributed impedance elements together with lumped impedance elements
• CPC Class Codes: H03H 7/1725 Element to ground being common to different shunt paths, i.e. Y-structure
• CPC Class Codes: H03H 7/1758 Series LC in shunt or branch path H03H7/1791 takes precedence
• CPC Class Codes: H03H 7/1766 Parallel LC in series path H03H7/1783 takes precedence
• CPC Class Codes: H04B 1/50 using different frequencies for the two directions of communication

Abstract

Systems and methods are disclosed for a wireless communications device for receiving wireless electronic signals including first wireless electronic signals at a first frequency and second wireless electronic signals at a second frequency. The wireless communications device includes an antenna adapted to convert the wireless electronic signals into input electronic signals, and an amplifier coupled to the antenna, said amplifier being capable of amplifying the input electronic signals to produce amplified electronic signals and a diplexer adapted to receive the amplified electronic signals and selectively output one of the first electronic signals at the first frequency and the second electronic signals at the second frequency.

Claims

1. A wireless communications device for generating transmitted electronic signals in response to input electronic signals having first input electronic signals at a first frequency and second input electronic signals at a second frequency, comprising:

a) a diplexer adapted to receive the input electronic signals and selectively output one of first electronic signals and second filtered electronic signals, including;

b) a first frequency filtering circuit, comprising

a first resonator circuit to receive the input electronic signals, said first resonator circuit comprising a first transmission line and a first capacitor coupled to the first transmission line;

a second resonator circuit in parallel to the first resonator circuit, said second resonator circuit comprising a second transmission line and a second capacitor coupled to the second transmission line to produce first filtered electronic signals at the first frequency; and

a coupling circuit that couples the first resonator circuit and the second resonator circuit;

c) a second frequency filtering circuit, comprising

a third resonator circuit to receive to receive the input electronic signals, said third resonator circuit comprising a third transmission line and a third capacitor coupled to the third transmission line;

a fourth resonator circuit in parallel to the third resonator circuit, said fourth resonator circuit comprising a fourth transmission line and a fourth capacitor coupled to the fourth transmission line to produce a second filtered electronic signals at the second frequency; and

a coupling circuit that couples the third resonator circuit and the fourth resonator circuit;

d) a power amplifier coupled to the diplexer, said power amplifier being capable of amplifying the selected one of the first filtered electronic signals and the second filtered electronic signals from the diplexer to produce amplified electronic signals; and

e) an antenna adapted to receive the amplified electronic signals to produce the transmission electronic signals.

2. The wireless communications device of claim 1, wherein the frequency filtering circuit is fabricated on a semiconductor substrate.

3. The wireless communications device of claim 1, wherein the frequency filtering circuit is fabricated on a passive semiconductor substrate.

4. The wireless communications device of claim 1, wherein the coupling circuit includes

a third capacitor;

and

a first inductor in parallel to the third capacitor, wherein the third capacitor and the first inductor are coupled to the first transmission line and the second transmission line.

5. The wireless communications device of claim 1, wherein the coupling circuit includes a second inductor that is connected grounded at one end and is coupled with the first capacitor and the second capacitor at another end.

6. The wireless communications device of claim 1, wherein the first transmission line is grounded at first end and is connected to the first capacitor at the second end.

7. The wireless communications device of claim 1, wherein the coupling circuit couples with the first resonator circuit at the first end of the first transmission line.

8. The wireless communications device of claim 1, wherein the second transmission line is grounded at first end and is connected to the second capacitor at the second end.

9. The wireless communications device of claim 1, wherein the coupling circuit couples with the second resonator circuit at the first end of the second transmission line.

10. The wireless communications device of claim 1, wherein the layout of first transmission line or the second transmission line includes a folded hairpin geometry.

11. The wireless communications device of claim 1, wherein the layout of the first transmission line and the second transmission line include substantially symmetric folded hairpin geometries.

12. The wireless communications device of claim 1, wherein the length of the first transmission line is substantially one quarter of the wavelength of the resonant frequency of the first resonator circuit.

13. The wireless communications device of claim 1, further comprising:

input electric signals provided to the first resonator circuit; and

output electric signals received from the second resonator circuit in response to the input electric signals, wherein the frequency performance function of the output electric signals includes at least one downward notch at a frequency adjacent to one side the pass band.

14. The wireless communications device of claim 13, wherein the frequency performance function of the output electric signals forms a pass band around a peak frequency.

15. The wireless communications device of claim 14, wherein the peak frequency is about 2 GHz or 5 GHz.

16. The wireless communications device of claim 1, wherein the frequency performance function of the output electric signals forms a low-pass band.

17. The wireless communications device of claim 1, wherein the frequency performance function of the output electric signals forms a high-pass band.

18. A wireless communications device for receiving wireless electronic signals including first wireless electronic signals at a first frequency and second wireless electronic signals at a second frequency, comprising:

a) an antenna adapted to convert the wireless electronic signals into input electronic signals; and

b) an amplifier coupled to the antenna, said amplifier being capable of amplifying the input electronic signals to produce amplified electronic signals; and

c) a diplexer adapted to receive the first filtered electronic signals and the second filtered electronic signals and selectively output one of the first filtered electronic signals at the first frequency and the second filtered electronic signals at the second frequency, including;

d) a first frequency filtering circuit, comprising

a first resonator circuit to receive the input electronic signals, said first resonator circuit comprising a first transmission line and a first capacitor coupled to the first transmission line;

a second resonator circuit in parallel to the first resonator circuit, said second resonator circuit comprising a second transmission line and a second capacitor coupled to the second transmission line to produce first filtered electronic signals at the first frequency; and

a coupling circuit that couples the first resonator circuit and the second resonator circuit;

e) a second frequency filtering circuit, comprising

a third resonator circuit to receive to receive the input electronic signals, said third resonator circuit comprising a third transmission line and a third capacitor coupled to the third transmission line;

a fourth resonator circuit in parallel to the third resonator circuit, said fourth resonator circuit comprising a fourth transmission line and a fourth capacitor coupled to the fourth transmission line to produce a second filtered electronic signals at the second frequency; and

a coupling circuit that couples the third resonator circuit and the fourth resonator circuit.

19. The wireless communications device of claim 18, wherein the frequency filtering circuit is fabricated on a semiconductor substrate.

20. The wireless communications device of claim 18, wherein the semiconductor substrate is a passive semiconductor substrate.

21. The wireless communications device of claim 18, wherein the coupling circuit includes

a third capacitor;

and

a first inductor in parallel to the third capacitor, wherein the third capacitor and the first inductor are coupled to the first transmission line and the second transmission line.

22. The wireless communications device of claim 18, wherein the coupling circuit includes a second inductor that is connected grounded at one end and is coupled with the first capacitor and the second capacitor at another end.

23. The wireless communications device of claim 18, wherein the first transmission line is grounded at first end and is connected to the first capacitor at the second end.

24. The wireless communications device of claim 18, wherein the coupling circuit couples with the first resonator circuit at the first end of the first transmission line.

25. The wireless communications device of claim 18, wherein the second transmission line is grounded at first end and is connected to the second capacitor at the second end.

26. The wireless communications device of claim 18, wherein the coupling circuit couples with the second resonator circuit at the first end of the second transmission line.

27. The wireless communications device of claim 18, wherein the layout of first transmission line or the second transmission line includes a folded hairpin geometry.

28. The wireless communications device of claim 18, wherein the layout of the first transmission line and the second transmission line include substantially symmetric folded hairpin geometries.

29. The wireless communications device of claim 18, wherein the length of the first transmission line is substantially one quarter of the wavelength of the resonant frequency of the first resonator circuit.

30. The wireless communications device of claim 18, further comprising:

input electric signals provided to the first resonator circuit; and

output electric signals received from the second resonator circuit in response to the input electric signals, wherein the frequency performance function of the output electric signals includes at least one downward notch at a frequency adjacent to one side the pass band.

31. The wireless communications device of claim 30, wherein the frequency performance function of the output electric signals forms a pass band around a peak frequency.

32. The wireless communications device of claim 31, wherein the peak frequency is about 2 GHz or 5 GHz.

33. The wireless communications device of claim 18, wherein the frequency performance function of the output electric signals forms a low-pass band.

34. The wireless communications device of claim 18, wherein the frequency performance function of the output electric signals forms a high-pass band.

35. The wireless communications device of claim 18, wherein the amplifier is a low noise amplifier.