Tunable microstrip devices

• US 7,696,929 B2
• Filed: 11/09/2007
• Issued: 04/13/2010
• Est. Priority Date: 11/09/2007
• Status: Expired due to Fees

• Current Assignee: RPX Corporation
• Original Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Inventors: Kaneda, Noriaki
• Primary Examiner(s): Dinh; Trinh V
• Assistant Examiner(s): DUONG, DIEU HIEN
• Application Number:
  US11/937,561
• Publication Number:
  US 20090121951A1
• Time in Patent Office: 886 Days
• Field of Search: 343/700.MS, 343/702, 343/745
• US Class Current: 343/700.0MS
• CPC Class Codes: H01P 7/082 Microstripline resonators H01P7/088 takes precedence
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

Tunable microstrip devices formed by capacitively coupled conductive strips are disclosed. Device parameters can be tuned by adjusting corresponding lengths of a resonator and a coupling section of the device by connecting one or more auxiliary segments to the conductive strips.

Claims

1. A method of tuning a microstrip device, comprising:

configuring a first conductive strip on a planar surface and over a conducting ground plane, the first conducting strip being formed of separated conducting segments arranged in a physical series on the planar surface and a second conductive strip located on the planar surface and over the conducting ground plane, a dielectric substrate being between the ground plate and the conducting strips;

providing a first set of micro-electromechanical system (MEMS) switches;

wherein the conducting strips are configured in a parallel arrangement and separated by a gap;

wherein part of one edge of the first conducting strip faces and is adjacent to part of one edge of the second conducting strip; and

wherein each adjacent pair of the separated conducting segments are electrically connectable via a corresponding one of the MEMS switches; and

tuning a parameter of the device by electrically connecting at least a first of the separated conducting segments of the first group to the first end of the first conductive strip using a first of the MEMS switches of the first set.

2. The method of claim 1, further comprising:

tuning the parameter of the device by electrically connecting one or more of the other separated conducting segments to the first of the separated conducting segments of the first group using one or more of the MEM switches of the first set.

3. The method of claim 1, further comprising:

providing a second set of MEMS switches and a second group of separated conducting segments, the second group of separated conducting segments disposed to form a second series at a second end of the first conductive strip, each separated conducting segment of the second group being associated with a corresponding one of the MEMS switches of the second set; and

tuning a parameter of the device by electrically connecting at least a first of the separated conducting segments of the second group to the second end of the first conductive strip using a first of the MEMS switches of the second set.

4. The method of claim 3, wherein each MEMS switch of the second set is disposed on the same side of the first conductive strip as the MEMS switches of the first set.

5. A tunable microstrip device, comprising:

a conducting ground plane;

a planar dielectric substrate having a planar surface;

a first conducting strip located on the planar surface and over the conducting ground plane, the first conducting strip being formed of a first group of separated conducting segments arranged in a physical series on the planar surface;

a second conducting strip located on the planar surface and over the conducting ground plane, the dielectric substrate being between the ground plate and the conducting strips; and

a first set of MEMS switches; and

wherein the conducting strips are configured in a parallel arrangement and separated by a gap;

wherein part of one edge of the first conducting strip faces and is adjacent to part of one edge of the second conducting strip; and

wherein each adjacent pair of the separated conducting segments are electrically connectable via a corresponding one of the MEMS switches.

6. The device of claim 5, comprising a resonator formed by the first conducting strip and any separated conducting segments connected to the first conducting strip.

7. The device of claim 6, wherein the device is an antenna having an input or output coupling tunable by connecting one or more of the separated conducting segments of the first group to the first conducting strip via one or more of the MEMS switches and having a central response frequency tunable by connecting one or more of the separated conducting segments of the first group to the first conducting strip via one or more of the MEMS switches.

8. The device of claim 5, wherein the first conductive strip further comprises a second set of MEMS switches and a second group of separated conducting segments disposed to form a second series at a second end of the first conducting strip, each separated conducting segments of the second group being associated with a corresponding one of the MEMS switches of the second set,

wherein a first of the MEMS switches of the second set is adapted to electrically connect one of the separated conducting segments of the second group to the second end of the first conducting strip via a MEMS switch of the second set, and each other MEMS switch of the second set is adapted to electrically connect one of the separated conducting segments in the second group to another of the separated conducting segments of the second group that is closer in the second series to the first conducting strip.

9. The device of claim 8, wherein each MEMS switch of the second set is disposed on a same side of the first conductive strip as the MEMS switches of the first set.

10. The device of claim 8, comprising a resonator formed by the main segment and any separated conducting segments from the first and the second groups connected to the first conducting strip.

11. The device of claim 8, wherein the separated conducting segments in the first group and the second group are quasi-rectangular shaped.

12. The device of claim 8, wherein the first and second groups of separated conducting segments have a same number of conducting strips, and all separated conducting segments in each group are similar.

13. The device of claim 8, further comprising:

a third conductive strip having a coupling section disposed adjacent to a second capacitive coupling section of the first conductive strip, the third conductive strip and the second conductive strip being on opposite sides of the first conductive strip;

wherein the second coupling section of the first conductive strip is formed by at least a portion of the first conducting strip and one or more separated conducting segments of the second group; and

the second set of MEMS switches and the first set of MEMS switches are disposed on opposite sides of the first conductive strip.

14. The device of claim 13, wherein the device is a filter having an input or output coupling tunable by connecting one or more of the separated conducting segments to the first conducting strip via one or more of the MEMS switches, and having a central response frequency tunable by connecting one or more of the separated conducting segments to the first conducting strip via one or more of the MEMS switches.

15. The device of claim 5, wherein the second conductive strip is a feed line of the device, and a section of the second conductive segment adjacent the first capacitive coupling section of the first conductive segment comprises a main segment and a third group of separated conducting segments forming a series at an end of the main segment of the second conductive strip;

and

a third set of MEMS switches, each switch of the third set adapted to electrically connect a corresponding one of the separated conducting segments of the third group to one of the segments of the second conductive strip.

16. The device of claim 15, wherein each of the MEMS switches of the third set is disposed on a second side of the second conductive strip that is farther away from the first conductive strip than the first side of the second conductive strip.

17. The device of claim 5, wherein the first and second conductive strips are provided on a front side of the dielectric substrate;

and

the device comprises a conductive ground plane on a back side of the dielectric substrate.

18. The device of claim 5, wherein the first and second conductive strips are on a front side of the dielectric substrate and the conductive ground plane is on a back side of the dielectric substrate, and the conductive ground plane has a boundary at a location opposite an intermediate point of the first conductive strip.

19. The device of claim 5, further comprising two conductive strips provided on the conductive ground plane on a side of the dielectric opposite to the first and second conductive strips, each of the conductive strips on the conductive ground plane comprising one or more switchable separated conducting segments for tuning a characteristic of the device.

20. The device of claim 19, wherein the device is one of a dipole antenna and a planar inverted-F type antenna.