Low noise figure radiofrequency device

• US 7,738,853 B2
• Filed: 04/30/2007
• Issued: 06/15/2010
• Est. Priority Date: 10/29/2004
• Status: Expired due to Fees

• Current Assignee: ANTONE Wireless Corporation (Westell Technologies Incorporated)
• Original Assignee: ANTONE Wireless Corporation (Westell Technologies Incorporated)
• Inventors: Hey-Shipton, Gregory L., Eddy, Michael M.
• Primary Examiner(s): Dao; Minh D
• Application Number:
  US11/742,562
• Publication Number:
  US 20070202920A1
• Time in Patent Office: 1,142 Days
• Field of Search: 455/341, 455/127.3, 455/194.2, 455/153.2, 455/311, 455/114.3, 455/144, 455/293, 330/303, 330/336, 333/134, 333/206, 375/272
• US Class Current: 455/341
• CPC Class Codes: H01P 1/2053 the coaxial cavity resonators being disposed parall to each other
• CPC Class Codes: H01P 1/2084 with dielectric resonators
• CPC Class Codes: H01P 7/10 Dielectric resonators
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them
• 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

Abstract

A RF device such as a tower mounted amplifier (TMA), mast-head amplifier (MHA), or Tower Mounted Boosters (TMB) includes a housing having a plurality of cavities and an input and an output, the input being coupled to the antenna and the output being coupled to a base station. The housing includes a transmission path holding multiple coaxial resonators. The housing further includes multiple receive paths including at least one path having a plurality of cavities, each cavity containing a dielectric resonator. The metallic transmit resonator nearest the antenna input is coupled to the first dielectric resonator via a common resonant wire. The last dielectric resonator in the receive path is coupled to a first metallic resonator of a downstream clean-up filter via another common resonant wire.

Claims

1. A radiofrequency device adapted for coupling to an antenna comprising:

a housing having a plurality of cavities and an input and output, the input being operatively coupled to the antenna, the output being operatively coupled to a base station;

a transmission path disposed within the housing and including a plurality of transmit resonators;

a receive path disposed within the housing, the receive path including a plurality of filter sections, each filter section including a plurality of receive resonators;

a low noise amplifier operatively coupled via an input to a last resonator in one of the plurality of filter sections, the low noise amplifier being operatively coupled via an output to the input of another of the plurality of filter sections; and

wherein the radiofrequency device has a noise figure of less than 1.2 dB at the center band.

2. The radiofrequency device according to claim 1, wherein the receive path comprises a first receive filter section having a plurality of cavities, each cavity holding a dielectric resonator.

3. The radiofrequency device according to claim 2, wherein the receive path includes a clean-up filter section comprising at least one cavity disposed within the housing, the at least one cavity containing one or more coaxial resonators.

4. The radiofrequency device according to claim 3, wherein a conductor is secured to a first coaxial resonator in the clean-up filter section, the conductor also being operatively coupled to a last dielectric resonator in the receive path, the conductor at least partially surrounding the last dielectric resonator in a non-contact arrangement.

5. The radiofrequency device according to claim 2, wherein a conductor is secured to a first transmit resonator in the transmission path, the conductor also being operatively coupled to a first dielectric resonator in the receive path, the conductor at least partially surrounding the first dielectric resonator in a non-contact arrangement.

6. The radiofrequency device according to claim 2, further including a tunable resonant coupling element configured to generate a frequency variable transmission zero comprising a predominantly magnetic coupling between non-adjacent dielectric resonators in the receive path and the magnetic field of the resonant coupling element, the tuning effect being generated by changing the resonant frequency of the coupling element.

7. The radiofrequency device according to claim 6, wherein the transmission zero is disposed between a second and fourth dielectric resonator in an eight-pole dielectric resonator system.

8. The radiofrequency device according to claim 6, further including a second resonant coupling element configured to generate a frequency variable transmission zero comprising a predominantly magnetic coupling between non-adjacent dielectric resonators in the receive path and the magnetic field of the second resonant coupling element, the tuning effect being generated by changing the resonant frequency of the coupling element.

9. The radiofrequency device according to claim 8, wherein the second transmission zero is disposed between a fifth and seventh dielectric resonator in an eight-pole dielectric resonator system.

10. The radiofrequency device according to claim 2, wherein a ratio of the diameter of the cavity to a diameter of the dielectric resonator contained in the cavity is less than 1.5:

1.

11. The radiofrequency device according to claim 1, wherein the radiofrequency device is located between the antenna and a base station.

12. The radiofrequency device according to claim 1, wherein the radiofrequency device has a noise figure of less than 1.2 dB over a substantial portion of a receive frequency band of interest.

13. The radiofrequency device according to claim 12, wherein the frequency band of interest comprises a sub-band within the range of 1.5 GHz to 2.5 GHz.

14. The radiofrequency filter device according to claim 1, wherein the low noise amplifier is disposed on a low loss dielectric printed circuit board having a dissipation factor (Df) of 0.004 or less.

15. A radiofrequency device adapted for coupling to an antenna comprising:

a housing having a plurality of cavities and an input and output, the input being operatively coupled to the antenna, the output being operatively coupled to a base station;

a transmission path disposed within the housing and including a plurality of transmit resonators;

a pre-LNA filter section disposed within the housing, the pre-LNA filter section including a receive filter having a plurality of cavities, each cavity holding a dielectric resonator, the pre-LNA filter section further comprising a clean-up filter, the clean-up filter including at least one cavity disposed within the housing, the at least one cavity containing one or more coaxial resonators;

a low noise amplifier operatively coupled to a last coaxial resonator in the clean-up filter, the low noise amplifier being operatively coupled to the input of a post-LNA receive filter; and

wherein the radiofrequency device has a noise figure of less than 1.2 dB at the center band.

16. The radiofrequency device according to claim 15, wherein the radiofrequency device is located between the antenna and a base station.

17. The radiofrequency device according to claim 15, wherein a conductor is secured to a first coaxial resonator in the clean-up filter, the conductor also being operatively coupled to a last dielectric resonator in the pre-LNA filter section, the conductor at least partially surrounding the last dielectric resonator.

18. The radiofrequency device according to claim 15, wherein the radiofrequency device has a noise figure of less than 1.2 dB over a substantial portion of a receive frequency band of interest.

19. The radiofrequency device according to claim 18, wherein the frequency band of interest comprises a sub-band within the range of 1.5 GHz to 2.5 GHz.

20. The radiofrequency device according to claim 15, wherein a conductor is secured to a first transmit resonator in the transmission path, the conductor also being operatively coupled to a first dielectric resonator in the pre-LNA filter section, the conductor at least partially surrounding the first dielectric resonator.

21. The radiofrequency device according to claim 15, further including a tunable resonant coupling element configured to generate a frequency variable transmission zero comprising a predominantly magnetic coupling between non-adjacent dielectric resonators in the pre-LNA filter section and the magnetic field of the resonant coupling element, the tuning effect being generated by changing the resonant frequency of the coupling element.

22. The radiofrequency device according to claim 21, wherein the transmission zero is disposed between a second and fourth dielectric resonator in an eight-pole dielectric resonator system.

23. The radiofrequency device according to claim 21, further including a second resonant coupling element configured to generate a frequency variable transmission zero comprising a predominantly magnetic coupling between non-adjacent dielectric resonators in the pre-LNA filter section and the magnetic field of the second resonant coupling element, the tuning effect being generated by changing the resonant frequency of the coupling element.

24. The radiofrequency device according to claim 23, wherein the second transmission zero is disposed between a fifth and seventh dielectric resonator in an eight-pole dielectric resonator system.

25. The radiofrequency device according to claim 15, wherein a ratio of the diameter of the cavity to a diameter of the dielectric resonator contained in the cavity is less than 1.5:

1.

26. The radiofrequency filter device according to claim 15, wherein the low noise amplifier is disposed on a low loss dielectric printed circuit board having a dissipation factor (Df) of 0.004 or less.

27. A radiofrequency device adapted for coupling to an antenna comprising:

a housing having an input and output, the input being operatively coupled to the antenna, the output being operatively coupled to a base station;

a transmission path within the housing including a plurality of transmit resonators;

a first receive filter disposed within the housing and including a plurality of cavities, each cavity holding a dielectric resonator, wherein a transmit resonator located closest to the input is coupled to a first dielectric resonator using a conductor connected to the transmit resonator and terminating adjacent to the first dielectric resonator;

a second receive filter disposed in the housing, wherein a last dielectric resonator in the first receive filter is coupled to a first receive resonator in the second receive filter via a conductor connected to the first receive resonator of the second receive filter and terminating adjacent to the last dielectric resonator; and

a low noise amplifier operatively coupled to a last resonator in the second receive filter, the low noise amplifier being operatively coupled to the input of a third receive filter.

28. The radiofrequency device according to claim 27, wherein the radiofrequency device is located between the antenna and a base station.

29. The radiofrequency device according to claim 27, wherein the radiofrequency device has a noise figure of less than 1.2 dB over a substantial portion of a receive frequency band of interest.

30. The radiofrequency device according to claim 29, wherein the frequency band of interest comprises a sub-band within the range of 1.5 GHz to 2.5 GHz.

31. The radiofrequency device according to claim 27, further including a tunable resonant coupling element configured to generate a frequency variable transmission zero comprising a predominantly magnetic coupling between non-adjacent dielectric resonators in the first receive filter and the magnetic field of the resonant coupling element, the tuning effect being generated by changing the resonant frequency of the coupling element.

32. The radiofrequency device according to claim 31, wherein the transmission zero is disposed between a second and fourth dielectric resonator in an eight-pole dielectric resonator system.

33. The radiofrequency device according to claim 31, further including a second resonant coupling element configured to generate a frequency variable transmission zero comprising a predominantly magnetic coupling between non-adjacent dielectric resonators in the first receive filter and the magnetic field of the second resonant coupling element, the tuning effect being generated by changing the resonant frequency of the coupling element.

34. The radiofrequency device according to claim 33, wherein the second transmission zero is disposed between a fifth and seventh dielectric resonator in an eight-pole dielectric resonator system.

35. The radiofrequency device according to claim 27, wherein a ratio of the diameter of the cavity to a diameter of the dielectric resonator contained in the cavity is less than 1.5:

1.

36. The radiofrequency filter device according to claim 27, wherein the low noise amplifier is disposed on a low loss dielectric printed circuit board having a dissipation factor (Df) of 0.004 or less.

37. The radiofrequency filter device according to claim 27, wherein the conductor coupling the transmit resonator closest to the input to the first dielectric resonator is resonant outside of the passband of the receive dielectric filter.

38. The radiofrequency filter device according to claim 27, wherein the conductor coupling the last dielectric resonator in the first receive filter to the first receive resonator in the second receive filter is resonant outside of the passband of the receive dielectric filter.