Inductor or antenna arrangement with integral series resonating capacitors

• US 3,946,397 A
• Filed: 12/16/1974
• Issued: 03/23/1976
• Est. Priority Date: 12/16/1974
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Irwin, James S.
• Primary Examiner(s): Lieberman, Eli
• Application Number:
  US05/532,989
• Time in Patent Office: 463 Days
• Field of Search: 343/744, 343/787, 343/788, 343/895, 336/69
• US Class Current: 343/788
• CPC Class Codes: H01Q 7/08 Ferrite rod or like elongated core

Abstract

An improved inductor arrangement suitable for a wide variety of applications, but particularly advantageous for use in the design of ferrite antenna structures intended to operate at the relatively higher frequencies. The disclosed inductor arrangement includes a spiral inductor or coil divided into a plurality of wire segments, respective pairs of which are interconnected by individual capacitance elements to form a plurality of series-resonant circuits at a particular frequency or range of interest. The capacitance elements may be provided in the form of discreet components or by a suitable electro-deposition process in the interests of further optimizing size factor. The number of individual wire segments and resonating capacitance elements may be selected to provide a given terminal impedance for the inductor arrangement within a certain limited design range.

Claims

1. An improved series-resonant inductor circuit component arrangement, comprising in combination:

a wire conductor of a predetermined length wound in helical form of substantially uniform diameter and having respective ends for connection to associated circuitry, said conductor being divided into a plurality of individual wire segments, each capable of resonance at a particular frequency of interest; and

a plurality of series-resonating capacitors individually interconnecting a respective pair of said inductor wire segments, respectively, to form a plurality of series-resonant tuned circuits,

the number of said wire segments and said series-resonating capacitors being selected to determine generally the terminal impedance of said inductor arrangement presented at said terminal ends.

2. An improved series-resonant inductor arrangement in accordance with claim 1 wherein said plurality of series-resonating capacitors are provided in descreet component element form.

3. An improved series-resonant inductor arrangement in accordance with claim 1 wherein said plurality of series-resonating capacitors are provided as thin, insulating pads suitably deposited between overlapping end portions of said respective pairs of said inductor wire segments.

4. An improved loop ferrite antenna arrangement effectively desensitized to hand capacity effects, comprising in combination:

a ferrite magnetic core;

a spiral conductor wound on said core as a closed loop, said conductor being divided into a plurality of wire segments capable of individually resonating within a particular frequency range of interest; and

a plurality of series-resonating capacitors individually interconnecting respective pairs of said wire segments to form a plurality of series-resonant tuned circuits within said frequency range of interest.

5. An improved ferrite antenna arrangement in accordance with claim 4 wherein said plurality of series-resonating capacitors are provided in discreet component element form.

6. An improved ferrite antenna arrangement in accordance with claim 4 wherein said plurality of series-resonating capacitors are provided as thin, insulating pads suitably deposited between overlapping end portions of said respective pairs of said conductor wire segments.

7. An improved ferrite antenna arrangement in accordance with claim 4 wherein the number of wire segments and interconnecting series-resonating capacitors may be selected to provide a desired number of turns of said conductor on said magnetic core independent of terminal reactance required.

8. An improved ferrite antenna arrangement in accordance with claim 4 wherein said spiral conductor is in the form of a flat metallic ribbon.