1-100 GHz microstrip filter

• US 6,771,147 B2
• Filed: 02/28/2002
• Issued: 08/03/2004
• Est. Priority Date: 12/17/2001
• Status: Expired due to Term

• Current Assignee: Remec Defense & Space Incorporated (Cobham PLC)
• Original Assignee: REMEC, Inc.
• Inventors: Mongia, Rajesh
• Primary Examiner(s): Pascal, Robert
• Assistant Examiner(s): Glenn, Kimberly E
• Application Number:
  US10/090,100
• Publication Number:
  US 20020180569A1
• Time in Patent Office: 887 Days
• Field of Search: 333/204, 333/219, 333/205, 333/246
• US Class Current: 333/204
• CPC Class Codes: H01P 1/20363 Linear resonators
• CPC Class Codes: H01P 1/20381 Special shape resonators

Abstract

A high frequency filter design for the GHz frequency range is provided. The high frequency filter comprises at least a microstrip design that incorporates both transverse and lateral couplings between the filters resonators. The high frequency filter further incorporates an opened or fully enclosed enclosure over the strip line or microstrip circuitry and may be manufactured on a relatively thick dielectric substrate having a thickness that is greater than about a twentieth of the filter'"'"'s band-pass wavelength in the dielectric substrate. The high frequency filter design provides a small, easily reproducible filter design better than prior art microstrip filters.

Claims

1. A microstrip filter adapted to operate in a frequency range between 1 and 100 GHz, said microstrip filter comprising:

a plurality of resonators having a longitudinal gap between each one of said resonators,

an input portion having a first transverse gap between said input portion and a first one of said plurality of resonators,

a dielectric block having said plurality of resonators on a first side, dielectric block being at least one-twentieth of the microstrip filter'"'"'s pass-band frequency'"'"'s wavelength in the dielectric block, and

an enclosure at least partially covering said plurality of resonators, said enclosure operating as a pseudo waveguide having a cutoff frequency that is higher than an operating frequency of said microstrip filter.

2. The microstrip filter of claim 1, wherein said enclosure has a length dimension and is open at opposite ends of its length.

3. The microstrip filter of claim 1, further comprising an output portion having a transverse gap between said output portion and a last one of said plurality of resonators.

4. The microstrip filter of claim 3, wherein said enclosure is open near a least one of said input portion and said output portion.

5. The microstrip filter of claim 4, wherein said enclosure substantially encloses said plurality resonators.

6. The microstrip filter of claim 1, wherein said microstrip filter is adapted to operate frequency range between 1 GHz and 25 GHz.

7. The microstrip filter of claim 6, wherein said dielectric block has a thickness ranging from about 200 mils to about 15 mils.

8. The microstrip filter of claim 1, wherein said dielectric block has a thickness of between 200 mils and 15 mils the microstrip filter is adapted to operate in a frequency range between 1 GHZ and 25 GHz.

11. The high frequency filter of claim 8, wherein said enclosure is open adjacent to said input portion.

12. The high frequency filter of claim 11, wherein said enclosure comprises a conductive material on a surface of said enclosure.

9. A high frequency filter comprising:

a dielectric substrate having a top side and a bottom side, the thickness of said dielectric substrate, from said top side to said bottom side, is at least one-twentieth of the high frequency filter'"'"'s pass-band frequency'"'"'s wavelength in said dielectric substrate;

an input portion on said top side of said dielectric substrate,

a first resonator portion spaced transversely from said input portion and on said top side;

a second resonator portion spaced longitudinally and on said top side; and

one or more additional resonators spaced longitudinally from said second resonator and each other respectively, said one or more additional resonators being on said top side;

an output portion on said top side of said dielectric substrate, said output portion being spaced transversely from a one of said one or more additional resonators,

an open ended enclosure over at least said first resonator, said second resonator, and said one or more additional resonators, said open ended enclosure adapted to operate as a pseudo-wave guide having a cut off frequency above an operating frequency of said high frequency filter.

10. The high frequency filter of claim 9, further comprising a ground plane on said bottom side of said dielectric substrate.

13. The high frequency filter of claim 9, further comprising a carrier plate, said dielectric substrate being attached to said carrier plate.

14. The high frequency filter of claim 9, wherein said filter is at least one of a band-pass, low pass and a high pass filter.

15. The high frequency filter of claim 9, wherein said filter is at least one of a strip line filter and a microstrip filter.

16. The high frequency filter of claim 9, wherein at least one of said first, second and third resonators have a variation in their width over their length.

17. The high frequency filter of claim 9, wherein said high frequency filter is adapted to operate at frequencies substantially between 1 GHz and 100 GHz.

18. The high frequency filter of claim 9, wherein said high frequency filter is adapted to operate in a frequency range between 1 GHz and 25 GHz.

19. The high frequency filter of claim 18, wherein said dielectric block has a thickness ranging from about 200 mils to about 15 mils.

20. The high frequency filter of claim 9, wherein said dielectric block has a thickness of between 200 mils and 15 mils and the microstrip filter is adapted to operate in a frequency range between 1 GHz and 25 GHz.

21. An electronic system that is adapted to process high frequency signals comprising:

a high frequency filter, said high frequency filter comprising;

a dielectric substrate having a top surface and a bottom surface, the thickness of said dielectric substrate, from said top surface to said bottom surface, being at least one-twentieth of the high frequency filter'"'"'s pass-band frequency'"'"'s wavelength in said dielectric substrate;

a plurality of resonators spaced from each other on said top surface and adapted to be longitudinally coupled;

an input portion spaced from a first one of said plurality of resonators, said input portion adapted to transversely couple with said first one of said plurality of resonators,

an output portion spaced from a last one of said plurality of resonators, said output portion adapted to transversely couple with said last one of said plurality of resonators; and

an enclosure substantially covering said plurality of resonators, said enclosure adapted to operate as a pseudo-wave guide having a cut off frequency above the operating frequency of said high frequency filter.

22. The electronic system of claim 21 wherein said enclosure is open-ended substantially near at least one of said input portion and said output portion.

23. The electronic system of claim 21, wherein said high frequency filter is adapted to operate in a frequency range between 1 GHz and 25 GHz.

24. The electronic system of claim 23, wherein said dielectric block has a thickness ranging from about 200 mils to about 15 mils.

25. The electronic system of claim 21, wherein said dielectric block has a thickness of between 200 mils and 15 mils and the microstrip filter is adapted to operate in a frequency range between 1 GHz and 25 GHz.

26. A high frequency filter comprising:

a dielectric substrate having a top surface and a bottom surface, the thickness of said dielectric substrate, from said top surface to said bottom surface, being at least one-twentieth of the high frequency filter'"'"'s pass-band frequency'"'"'s wavelength in said dielectric substrate,

a plurality of resonators spaced from each other on said top surface and adapted to be longitudinally coupled;

an input portion spaced from a first one of said plurality of resonators, said input portion adapted to transversely couple with said first one of said plurality of resonators,

an output portion spaced from a last one of said plurality of resonators, said output portion adapted to transversely couple with said last one of said plurality of resonators; and

an enclosure substantially covering said plurality of resonators, said enclosure adapted so operate as a pseudo-wave guide having a cut off frequency above the operating frequency of said high frequency filter.

27. The high frequency filter of claim 26, wherein said high frequency filter is adapted to operate in a frequency range between 1 GHz and 25 GHz.

28. The high frequency filter of claim 27, wherein said dielectric block has a thickness ranging from about 200 mils to about 15 mils.

29. The high frequency filter a claim 26, wherein said dielectric block has a thickness of between 200 mils and 15 mils and the microstrip filter is adapted to operate in a frequency range between 1 GHz and 25 GHz.

30. A microstrip filter adapted to operate in a frequency range between 1 and 100 GHz, said microstrip filter comprising:

a plurality of resonators having at least one of a longitudinal gap and a transverse gap between each one of said plurality of resonators,

a dielectric block having said plurality of resonators on a first side, said dielectric block having a thickness of a least one-twentieth of the microstrip filter'"'"'s pass-band frequency'"'"'s wavelength in the dielectric block; and

a covering that at least partially covers said plurality of resonators, said covering adapted to operate as a pseudo waveguide having a cutoff frequency that is higher than an operating frequency of said microstrip filter.

31. The microstrip filter of claim 30, wherein said microstrip filter is adapted to operate in a frequency range between 1 GHz and 25 GHz.

32. The microstrip filter of claim 31, wherein said dielectric block has a thickness ranging from about 200 mils to 15 mils.

33. The microstrip filter of claim 30, wherein said dielectric block has a thickness ranging from about 200 mils to about 15 mil and said microstrip filter is adapted to operate in a frequency range between 1 GHz and 25 GHz.

34. A microstrip comprising:

a plurality of capacitively coupled resonators;

a dielectric block having said plurality of capacitively coupled resonators on at least a first side of said dielectric block, said dielectric block having a thickness of at least one-twentieth of the microstrip filter'"'"'s pass-band frequency'"'"'s wavelength in the dielectric block; and

a covering over at least a portion of said plurality of capacitively coupled resonators, said covering adapted to function as a pseudo waveguide having a cutoff frequency that is higher than an intended operating frequency of said microstrip filter, said intended operating frequency being a selected frequency range between 1 GHz and 100 GHz.

35. The microstrip filter of claim 34, wherein said microstrip filter is adapted to operate in a frequency range between 1 GHz and 25 GHz.

36. The microstrip filter of claim 35, wherein said dielectric block has a thickness ranging from about 200 mils to 15 mils.

37. The microstrip filter of claim 34, wherein said dielectric block has a thickness of between 200 mils and 15 mils and the microstrip filter is adapted to operate within a frequency range of 1 GHz to 25 GHz.