Transmission channel coupler for antenna

• US 4,621,243 A
• Filed: 03/27/1985
• Issued: 11/04/1986
• Est. Priority Date: 12/30/1984
• Status: Expired due to Term

• Current Assignee: Harada Kogyo KK
• Original Assignee: Harada Kogyo KK
• Inventors: Harada, Takuji
• Primary Examiner(s): Nussbaum, Marvin L.
• Application Number:
  US06/716,826
• Time in Patent Office: 587 Days
• Field of Search: 333/24 R, 333/27, 333/24 C, 333/219, 333/202-208, 333/222, 333/227, 333/223, 333/231, 333/235, 343/712-715, 343/745, 343/749, 343/850, 343/856, 343/905, 343/906, 343/878, 343/700 R, 343/710
• US Class Current: 333/24.00R
• CPC Class Codes: H01P 1/20 Frequency-selective devices, e.g. filters
• CPC Class Codes: H01Q 1/1214 through a wall
• CPC Class Codes: H01Q 1/1285 with capacitive feeding through the windscreen

Abstract

A transmission channel coupler for an antenna including two resonators, each resonator being formed with a helical conductor and an outer conductor which is disposed outside of the helical conductor by sharing the same axis with the helical conductor. One end of the helical conductor is electrically connected to the inner wall of the outer conductor, and the other end of the helical conductor is connected to a printed circuit board mounted at the end of the outer conductor so that the helical conductor is positioned inside the outer conductor. The resonators are coaxially mounted on the either side of a glass such as the rear window of a car, window of a building, etc. By means of the structure above, high frequency signals are transmitted through an insulating material, that is, the glass, without damaging it. Also, the coupler can be manufactured small in size and provides excellent frequency characteristics with less transmission loss.

Claims

1. A transmission channel coupler for VHF or UHF antenna for coupling electromagnetic energy through an insulated material comprising:

an undergrounded outer conductor having first and second ends;

a helical conductor having first and second ends provided within and substantially coaxial with said outer conductor, said first end of said helical conductor being electrically connected to a point of an inner wall of said outer conductor which is adjacent said first end of said outer conductor, said helical conductor and said outer conductor being arranged and configured such that a ratio of an inside diameter of the outer conductor to an outside diameter of said helical conductor is 1.1-2.0;

a printed circuit board having a circular conductive pattern provided thereon, said printed circuit board being provided adjacent said second end of said outer conductor and having said circular conductive pattern electrically connected to said second end of said helical conductor, said circular conductive layer further being provided within said outer conductor.

2. A transmission channel coupler for an antenna according to claim 1, wherein the outer conductor is a cylindrical column in shape.

3. A transmission channel coupler for an antenna according to claim 1, wherein the conductive pattern and the outer conductor are separate and ungrounded.

4. A transmission channel coupler for an antenna according to claim 1, wherein the conductive pattern and the outer conductor are held in a state of being separated with a capacitance less than several picofarads.

5. A tranmission channel coupler for VHF or UHF antenna for coupling electromagnetic energy through an insulated material comprising:

a first resonator comprising;

an ungrounded outer conductor having first and second ends;

a helical conductor having first and second ends provided within and substantially coaxial with said outer conductor, said first end of said helical conductor being electrically connected to a point on an inner wall of said outer conductor which is adjacent said first end of said outer conductor, said helical conductor and said outer conductor being arranged and configured such that a ratio of an inside diameter of the outer conductor to an outside diameter of said helical conductor is 1.1-2.0; and

a printed circuit board having a circular conductive pattern provided thereon said printed circuit board being provided adjacent said second end of said outer conductor and having said circular conductive pattern electrically connected to said second end of said helical conductor, said circular conductive pattern further being provided within said outer conductor;

a second resonator having the same structure as that of the first resonator provided opposite said first resonator with said insulating material provided therebetween; and

a resonator fixing means for fixing an end face of the first resonator to an insulating material, fixing the end face of the second resonator to the insulating material and for fixing the first resonator and the second resonator along the same axis.

6. A transmission channel coupler for an antenna according to claim 5, wherein the shapes of the first resonator and the second resonator are determined such that when the coupling coefficient for the first resonator and the second resonator is set to be K and the Q factor at on load is set to be Q_L, the relationship of K·

Q_L =1 is approximately established.

7. A transmission channel coupler for an antenna according to claim 5, wherein:

the first resonator has an antenna connecting means in a part of its helical conductor, the connecting means being connected to the antenna;

the second resonator has a communication device connecting means in a part of its helical conductor to be connected to a communication device; and

the loaded Q factor of the first resonator and the loaded Q factor of the second resonator are approximately equal.

8. A transmission channel coupler for an antenna according to claim 5, wherein the resonance frequency of the first resonator is approximately the same as the resonance frequency of the second resonator.

9. A transmission channel coupler for an antenna according to claim 5, wherein the inside diameter of the outer conductor of the first resonator is approximately equal to the inside diameter of the second resonator.

10. A transmission channel coupler for an antenna according to claim 5, wherein the ratio of the inside diameter of the outer conductor in the first resonator or the second resonator to the outside diameter of the helical conductor of the first resonator or the second resonator is 1.2-2.0 when the outer conductor is cylindrical in shape.

11. A transmission channel coupler for an antenna according to claim 5, wherein the coiling direction of the helical conductor of the first resonator is the same as the coiling direction of the helical conductor of the second resonator.

12. A transmission channel coupler for an antenna according to claim 5, wherein the insulating material is a glass window of a car.

13. A transmission channel coupler for an antenna according to claim 5, wherein the resonator fixing means tightly contacts the first or second resonator between the insulating material.

14. A transmission channel coupler for an antenna according to claim 5, wherein the resonator fixing means interposes an adhesion tape or a protective insulator between the first or second resonator and the insulating material.

15. A transmission channel coupler for an antenna according to claim 5, wherein the insulating material is a glass window of a building.