Miniature radio transceiver antenna

• US 4,644,366 A
• Filed: 09/26/1984
• Issued: 02/17/1987
• Est. Priority Date: 09/26/1984
• Status: Expired due to Fees

• Current Assignee: Hale and Dorr LLP
• Original Assignee: Amitec Incorporated
• Inventors: Scholz, Frederick J.
• Primary Examiner(s): Lieberman, Eli
• Assistant Examiner(s): Wimer, Michael C.
• Application Number:
  US06/655,046
• Time in Patent Office: 874 Days
• Field of Search: 343/806, 343/702, 343/700 MS, 343/895, 343/718, 343/741-744, 343/748-750, 343/752, 343/867, 343/870, 343/866, 336/200, 455/269
• US Class Current: 343/895
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/27 Adaptation for use in or on movable bodies H01Q1/08, H01Q1/12, H01Q1/18 take precedence
• CPC Class Codes: H01Q 9/04 Resonant antennas

Abstract

A compact, lightweight, printed circuit card antenna which is adaptable to a wide range of frequencies, including very low frequencies. The antenna includes a three-dimensional inductor formed on the card, a peripheral conductor stripe on one side of the card which provides a distributed capacitance to the end of the antenna (to cancel inductive effects and broaden its bandwidth), and a peripheral conductor on the opposite side of the card which provides a capacitance to ground (to tune the antenna to frequency), and a transmission line feed point which provides an impedance match to the associated printed circuit flat cable transmission line without the use of impedance matching circuits.

Claims

1. An antenna comprising:

a dielectric sheet;

a first conductor pattern formed on a first side of the sheet;

a second conductor pattern formed on the second, opposite side of the sheet and aligned with and connected to corresponding conductors of the first pattern to thereby define a coil having first and second ends, the second end being for connection to ground;

a first peripheral conductor formed on the first side of the sheet about a selected length of the periphery of the sheet and connected to the first end of the coil for defining a distributed capacitance with respect to the adjacent conductor pattern; and

, a second peripheral conductor formed on the second side of the sheet about a selected length of the periphery of the sheet and being connected to the second, ground end of the coil for defining a capacitance with respect to the first peripheral conductor to provide a capacitance to ground.

2. An antenna comprising:

a dielectric sheet;

a first conductor pattern formed on a first side of the sheet;

a second conductor pattern formed on the second, opposite side of the sheet and aligned with and connected to corresponding conductors of the first pattern to thereby define a coil having first and second ends, the second end being for connection to ground;

a first peripheral conductor formed on the first side of the sheet about a selected length of the periphery of the sheet and connected to the first end of the coil for defining a distributed capacitance with respect to the adjacent conductor pattern;

a second peripheral conductor formed on the second side of the sheet about a selected length of the periphery of the sheet and being connected to the second, ground end of the coil for defining a capacitance with respect to the first peripheral conductor to provide a capacitance to ground; and

wherein the coil is connected via a transmission line to a transmission or receiving circuit at a point on the coil spaced a selected distance along the coil from the second, ground end to provide an impedance match with the transmission line.

3. An antenna, comprising:

a continuous printed circuit coil comprising a continuous array of conductive elements formed on opposite sides of a dielectric sheet and interconnected to form a continuous three-dimensional coil having first and second ends, the first end being suitable for connection to ground;

a first peripheral U-shaped conductor formed on one side of the sheet and forming a distributed capacitance with the elements on that side of the sheet, the first conductor being connected to the second end of the coil to connect the distributed capacitance to the second end of the coil; and

a second peripheral U-shaped conductor formed on the second side of the sheet and partially overlapping the first peripheral conductor to form a capacitance with respect to the first peripheral conductor;

the second conductor being connected to the first end of the coil for providing a lumped capacitance to ground.

4. The antenna of claim 3 wherein the frequency response of the antenna is determined by the length of the coil and the length of the second peripheral conductor combined with the magnitude of the capacitance to ground.