Loop antenna

• US 10,454,172 B2
• Filed: 08/26/2016
• Issued: 10/22/2019
• Est. Priority Date: 01/22/2016
• Status: Active Grant

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: Sasaki, Ai-ichiro, Mizota, Tsutomu, Morimura, Hiroki, Kagami, Osamu
• Primary Examiner(s): Nguyen, Hoang V
• Application Number:
  US15/757,249
• Publication Number:
  US 20180342806A1
• Time in Patent Office: 1,152 Days
• CPC Class Codes: H01Q 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them
• CPC Class Codes: H01Q 7/08 Ferrite rod or like elongated core
• CPC Class Codes: H01Q 9/04 Resonant antennas
• CPC Class Codes: H04B 5/48 Transceivers

Abstract

A main loop is an open loop that is wound on a bar-shaped rod formed of a magnetic body or an insulation body and that has terminals T and T that couple a signal source or a receiving circuit to the main loop. The number of turns is 1 or more. An amplifying loop is wound on a part of the rod that is different from the part on which the main loop is wound. The main loop and the amplifying loop are thus spaced from each other. The amplifying loop is a closed loop including no terminals. The number of turns is 1 or more. The number of turns may be the same as or different from the number of turns of the main loop.

Claims

1. A loop antenna that is applied to a radio system using a magnetic field, comprising:

a main loop that is an open loop to be coupled to a signal source or a receiving circuit; and

an amplifying loop that is a closed loop having a same shape as the main loop, wherein

the main loop and the amplifying loop are wound on a bar-shaped rod formed of a magnetic body or an insulation body,

a resistor and a capacitor are coupled to each of the main loop and the amplifying loop in series, and

a resistance coupled to the main loop is greater than a resistance coupled to the amplifying loop.

2. The loop antenna according to claim 1, wherein

the number of turns of the main loop and the number of turns of the amplifying loop are equal.

3. The loop antenna according to claim 2, wherein

the main loop and the amplifying loop are spaced from each other.

4. The loop antenna according to claim 2, wherein

the main loop and the amplifying loop are wound while running side by side to each other.

5. The loop antenna according to claim 1, wherein

the main loop and the amplifying loop are spaced from each other.

6. The loop antenna according to claim 1, wherein

the main loop and the amplifying loop are wound while running side by side to each other.