Compact wideband microstrip antenna with leaky-wave excitation

• US 6,285,325 B1
• Filed: 02/16/2000
• Issued: 09/04/2001
• Est. Priority Date: 02/16/2000
• Status: Expired due to Fees

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Nalbandian, Vahakn, Lee, Choon Sae
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Tran, Chuc
• Application Number:
  US09/505,090
• Time in Patent Office: 566 Days
• Field of Search: 343/700.MS, 343/849, 343/829, 343/830, 343/859, 343/702, 343/772, 343/853, 343/818, 343/846
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 13/206 Microstrip transmission line antennas
• CPC Class Codes: H01Q 19/005 Patch antenna using one or more coplanar parasitic elements

Abstract

A compact wideband leaky-wave excitation microstrip antenna is provided by a group of microstrip patches disposed on a top region of a dielectric substrate stacked on a conductive ground plane. The top region of the dielectric substrate and the dielectric substrate can be composed of either the same or different dielectric materials. A means for feeding an RF signal, which can be a center feed pin, that normally touches the top conducting patch is electrically isolated from the radiating patches. This arrangement confines the feed current within the probe pin to give an increased input resistance. The compact wideband leaky-wave excitation microstrip antenna permits significant reductions in antenna size, resulting in microstrip antennas with a smaller surface area.

Claims

1. A compact wideband leaky-wave excitation microstrip antenna, comprising:

a plurality of microstrip patches arranged on a top region of a dielectric substrate;

said dielectric substrate being stacked on a ground plate;

said plurality of microstrip patches forming a microstrip antenna cavity storing a quantity of stored electrical energy;

a means for feeding an RF signal extends from said ground plate through said dielectric substrate to an insulation gap within a first microstrip patch of said plurality of microstrip patches;

said antenna having a given Q factor, a given bandwidth and a given surface area;

each of said plurality of microstrip patches being separated by a gap and electrically coupled;

said plurality of microstrip patches, being electrically coupled and arranged on said top region, produce a quantity of electrical coupling to excite leaky-wave radiation having a higher voltage than said quantity of stored electrical energy decreasing said given Q to a reduced Q factor;

said reduced Q factor resulting in an increased bandwidth wider than said given bandwidth; and

said insulation gap, having a wider diameter than said feeding means, prevents ohmic contact between said feeding means and said first microstrip patch to provide an increased input resistance, an improved impedance matching and a wide bandwidth to permit a decreased antenna surface area.

2. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 1, further comprising said top region being on a top surface of said dielectric substrate.

3. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 2, further comprising said feeding means being located within said insulation gap without contacting said first microstrip patch.

4. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 3, further comprising said ground plate being conductive.

5. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 4, further comprising said plurality of microstrip patches being rectangular.

6. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 5, further comprising:

said top region having a thickness t₁;

said dielectric substrate having a thickness t₂; and

said ground plate having a thickness t₃.

7. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 6, further comprising said top region and said dielectric substrate being constructed of different dielectric materials.

8. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 7, further comprising said feeding means being coupled to a coaxial connector.

9. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 8, further comprising said feeding means being an electrical feed line.

10. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 9, further comprising said feeding means being an SMA center feed pin.

11. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 10, further comprising said plurality of microstrip patches being between four and seven microstrip patches.

12. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 11, further comprising said plurality of microstrip patches being five microstrip patches.

13. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 12, further comprising said antenna providing a 30% frequency bandwidth.

14. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 13, further comprising forming said plurality of conductive patches with a thin conductive material on said top region.

15. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 14, further comprising said thin conductive material being sufficiently thin to permit accurate photo-etching of said plurality of conductive patches.

16. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 15, further comprising said top region having a dielectric constant of approximately 10.

17. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 16, further comprising said top region having a dielectric constant of 10.

18. The compact wideband leaky-wave excitation microstrip antenna, as recited in claim 17, further comprising said dielectric substrate having a dielectric constant of approximately 1.0.