Composite right/left-handed transmission line based compact resonant antenna for RF module integration

• US 7,446,712 B2
• Filed: 12/20/2006
• Issued: 11/04/2008
• Est. Priority Date: 12/21/2005
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Itoh, Tatsuo, Lee, Cheng-Jung, Leong, Kevin M.
• Primary Examiner(s): Nguyen; Hoang V
• Application Number:
  US11/614,017
• Publication Number:
  US 20070176827A1
• Time in Patent Office: 685 Days
• Field of Search: 343/700.MS, 343/909, 343/754, 343/846, 343/749
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 13/206 Microstrip transmission line antennas
• CPC Class Codes: H01Q 21/065 Patch antenna array
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037

Abstract

An apparatus based on composite right-handed or left-handed (CRLH) principles to provide a transmission line or antenna structure having a plurality of cells to which one or more feed ports are attached. The apparatus is based on an equivalent circuit Right-Hand (RH) series induction (L_R) and shunt capacitor (C_R), and Left-Hand (LH) series capacitor (C_L) and induction (L_L), in which effective permittivity (e) and permeability (m) of the structure are manipulated by the choice of C_R, L_R, C_L, and L_L. One embodiment describes mushroom antenna cells (1D or 2D array) in which vias extend up from a feed network on a ground plane through at least one dielectric region to each of a first plurality of conductive elements (plates or strips). Optionally, a second plurality of conductive elements are disposed between first and second dielectric layers to form metal-insulator-metal (MIM) capacitors to lower resonance frequency.

Claims

1. An apparatus for transmitting or radiating radio frequencies within a composite right/left-handed (CRLH) transmission line, comprising:

at least one dielectric layer;

a first conducting element over said at least one dielectric layer;

a ground plane under said at least one dielectric layer;

a vertical conductor extending through said at least one dielectric layer to connect said first conducting element to said ground plane; and

means for guiding a signal along at least one waveguide within said ground plane and up through said vertical conductor passing through said at least one dielectric layer to said first conducting element,

wherein said CRLH based apparatus is configured using equivalent circuit models that comprises Right-Hand (RH) series induction (L_R) and shunt capacitor (C_R), and Left-Hand (LH) series capacitor (C_L) and induction (L_L); and

wherein the effective permittivity (e) and permeability (m) of the structure are manipulated by the choice of C_R, L_R, C_L, and L_L.

2. An apparatus as recited in claim 1, wherein said apparatus comprises an antenna when said signal is radiated from said apparatus, or a transmission line when said signal is transmitted through said apparatus.

3. An apparatus as recited in claim 1, further comprising a coplanar wavelength (CPW) stub within said ground plane at a connection to said vertical conductor.

4. An apparatus as recited in claim 1, further comprising:

a first dielectric layer, of a first thickness and having a first dielectric constant, within said at least one dielectric layer;

a second dielectric layer, of a second thickness and having a second dielectric constant, within said at least one dielectric layer;

said second dielectric layer positioned over said first dielectric layer;

wherein said first conducting element is positioned over said second dielectric layer, and said vertical conductor passes through both said first and second dielectric layer;

at least a second conductive element retained between said first and said second dielectric layers;

a metal-insulator-metal (MIM) capacitor formed in response to the proximal relation of said second conductive element in relation to said first conductive element; and

wherein said MIM capacitor is configured to lower the resonant frequency of said apparatus.

5. An apparatus as recited in claim 3, wherein said second dielectric constant is higher than said first dielectric constant.

6. An apparatus as recited in claim 3, wherein said second thickness is less than said first thickness.

7. An apparatus as recited in claim 1, wherein a plurality of first conducting elements and vertical conductors within said apparatus are arranged in a one or two dimensional array coupled to said means for guiding a signal.

8. An apparatus for transmitting or radiating radio frequencies within a composite right/left-handed (CRLH) transmission line, comprising:

a first dielectric layer forming a structure substrate;

second dielectric layer positioned over said first dielectric layer;

a ground plane disposed under said first dielectric layer;

a first plurality of conductive elements disposed over said second dielectric layer;

a second plurality of conductive elements disposed between said first and second dielectric layers and positioned to form metal-insulator-metal (MIM) capacitors in response to proximity with said first plurality of conductive elements, said capacitors lower the resonant frequency of said apparatus;

a plurality of vias interconnecting said first plurality of conductive elements with said ground conducting layer; and

at least one feed line attached to said first plurality of conductive elements;

wherein said CRLH based apparatus is configured using equivalent circuit models that comprises Right-Hand (RH) series induction (L_R) and shunt capacitor (C_R), and Left-Hand (LH) series capacitor (C_L) and induction (L_L); and

wherein the effective permittivity (e) and permeability (m) of the structure are manipulated by the choice of C_R, L_R, C_L, and L_L.

9. An apparatus as recited in claim 8:

wherein said first dielectric layer comprises a material having a first dielectric constant and a first thickness;

wherein said second dielectric layer comprises a material having a second dielectric constant and a second thickness;

wherein said second dielectric constant is higher than said first dielectric constant;

wherein said second dielectric thickness is less than said first dielectric thickness.

10. An apparatus as recited in claim 8, wherein said conductive elements comprise conductive plates or conductive strips.

11. An apparatus as recited in claim 8, wherein the frequency of said CRLH apparatus is in the range of frequencies between approximately hundreds of MHz and tens of GHz.

12. An apparatus as recited in claim 8:

wherein said vias are connected between each said conductive element in said first plurality of conductive elements, and said ground plane; and

wherein said vias are connected to each said conductive element either at the center of said conductive element as a symmetrical connection, or off of the center of said conductive element as non-symmetrical connection.

13. An apparatus as recited in claim 8, wherein said first plurality of conductive elements are positioned in a one-dimensional array of N number of cells.

14. An apparatus as recited in claim 13, herein said array has four cells.

15. An apparatus as recited in claim 13, wherein said array has a size of approximately a 1/19λ

×

1/23λ

×

1/83λ

.

16. An apparatus as recited in claim 13, wherein said N number of cells are cascaded in series in response to which the CRLH structure resonates at 2N+1 resonance, which is a mode of resonance.

17. An apparatus as recited in claim 13:

wherein n=0 is the zeroeth order mode, n=+1, +2 . . . , +(N−

1) are the RH resonance modes;

wherein e and m>

0, and n=−

1, −

2, . . . , −

(N−

1) are the LH modes; and

wherein e and m<

0, and where n is an integer multiple, e is effective permittivity and m is permeability.

18. An apparatus as recited in claim 8:

wherein said first dielectric layer comprises a material having a low dielectric constant approximately between two and five; and

wherein said second dielectric layer comprises a material having a higher dielectric constant of multiple order of the first layer dielectric constant.

19. An apparatus as recited in claim 8, wherein the physical size and operating frequency of the apparatus are determined by the unit cell size and equivalent transmission line model parameters.

20. An apparatus as recited in claim 8, wherein the size, operating frequency bands, and impedance matching of said apparatus depends on the unit cell equivalent (TL) parameters C_R, L_R, C_L, and L_L.

21. An apparatus as recited in claim 20, wherein the sizing of said apparatus is controlled in response to varying L_L and C_L whose effectiveness is in response to the small propagating wavelength value compared to the free space wavelength.

22. An apparatus as recited in claim 21, wherein said optional second plurality of conductive elements comprises metal-insulator-metal (MIM) capacitors that provide a high C_L to lower structure resonant frequency in response to utilizing a thin dielectric sheet with high dielectric constant.

23. An apparatus as recited in claim 8, wherein said feed line comprises a feed line having a characteristic impedance of 50 (ohms).

24. An apparatus for transmitting or radiating radio frequencies within a composite right/left-handed (CRLH) transmission line, comprising:

a first dielectric layer forming a structure substrate;

a second dielectric layer positioned over said first dielectric layer;

a ground plane disposed under said first dielectric layer;

a first plurality of conductive elements disposed over said second dielectric layer;

a second plurality of conductive elements disposed between said first and second dielectric layers and positioned to form metal-insulator-metal (MIM) capacitors in response to proximity with said first plurality of conductive elements, said capacitors lower the resonant frequency of said apparatus;

a plurality of vias interconnecting said first plurality of conductive elements with said ground conducting layer; and

at least one feed line attached to said first plurality of conductive elements;

wherein said apparatus comprises a CRLH-based device configured according to an equivalent circuit model that comprises Right-Hand (RH) series induction (L_R) and shunt capacitor (C_R), and Left-Hand (LH) series capacitor (C_L) and induction (L_L); and

wherein values for C_R, L_R, C_L, L_L, and N within said apparatus are selected to match a desired feed impedance.

25. An apparatus as recited in claim 24, wherein said first plurality of conductive elements are positioned in a two-dimensional array.

26. An apparatus as recited in claim 25, wherein said array is a three-by-three array.

27. An apparatus as recited in claim 25, wherein said array has a size of approximately 1/14λ

×

1/14λ

×

1/39λ

.

28. An apparatus for transmitting or radiating radio frequencies within a composite right/left-handed (CRLH) transmission line, comprising:

a first dielectric layer forming a structure substrate;

second dielectric layer positioned over said first dielectric layer;

a ground plane disposed under said first dielectric layer;

a first plurality of conductive elements disposed over said second dielectric layer;

a second plurality of conductive elements disposed between said first and second dielectric layers and positioned to form metal-insulator-metal (MIM) capacitors in response to proximity with said first plurality of conductive elements, said capacitors lower the resonant frequency of said apparatus;

a plurality of vias interconnecting said first plurality of conductive elements with said ground conducting layer; and

at least one feed line attached to said first plurality of conductive elements;

wherein said apparatus comprises an antenna;

wherein said feed line is configured as a dual-feed connection to said first plurality of conductive elements; and

whereby said antenna is circularly polarized in response to said dual-feed connection of said first and second feed lines to orthogonal edges of said antenna.

29. An apparatus as recited in claim 28, wherein said plurality of antenna elements comprises a three-by-three array and has a relative sizing of 1/10λ

×

1/10λ

×

1/36λ

.

30. An apparatus as recited in claim 29, wherein incorporation of a coplanar waveguide (CPW) feed line configures said apparatus for integration with a desired set of electronics and/or associated matching networks.

31. An apparatus, comprising:

a first dielectric layer forming a structure substrate;

a second dielectric layer positioned over said first dielectric layer;

a ground plane disposed beneath said first dielectric layer;

a first plurality of conductive elements disposed over said second dielectric layer;

a second plurality of conductive elements disposed between said first and second dielectric layers and positioned to form metal-insulator-metal (MIM) capacitors in response to proximity with said first plurality of conductive elements, said capacitors lower the resonant frequency of said apparatus;

a plurality of vias interconnecting said first plurality of conductive elements with said ground plane; and

at least one feed line attached to said first plurality of conductive elements;

said apparatus is configured using an equivalent circuit Right-Hand (RH) series induction (L_R) and shunt capacitor (C_R), and Left-Hand (LH) series capacitor (C_L) and induction (L_L), in which effective permittivity (e) and permeability (m) of the structure are manipulated by the choice of C_R, L_R, C_L, and L_L;

said first and second plurality of conductive elements comprise conductive plates or strips arranged in a one or two dimensional array of cells;

said first dielectric layer comprises a material having a first dielectric constant and a first thickness, and said second dielectric layer comprises a material having a second dielectric constant and a second thickness; and

said second dielectric constant is higher than said first dielectric constant, and said second dielectric thickness is less than said first dielectric thickness.