Spiral antenna

• US 8,564,500 B2
• Filed: 12/09/2010
• Issued: 10/22/2013
• Est. Priority Date: 03/29/2010
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tanabe, Masahiro, Nakano, Hisamatsu
• Primary Examiner(s): Ho, Tan
• Application Number:
  US12/964,034
• Publication Number:
  US 20110234471A1
• Time in Patent Office: 1,048 Days
• Field of Search: 343/700.MS, 343/792.5, 343/895
• US Class Current: 343/895
• CPC Class Codes: H01Q 17/00 Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems
• CPC Class Codes: H01Q 19/10 using reflecting surfaces
• CPC Class Codes: H01Q 9/27 Spiral antennas

Abstract

According to one embodiment, a spiral antenna includes an antenna element, a cavity, and a radio wave absorber. The spiral antenna is formed into a spiral shape on a dielectric substrate. The cavity is formed to have a space with the antenna element. The radio wave absorber is placed to cover a terminal end portion of the spiral.

Claims

1. A spiral antenna comprising:

an antenna element formed into a spiral shape on a dielectric substrate;

a cavity formed to have a space with the antenna element; and

a radio wave absorber placed on an upper surface of the dielectric substrate to cover a terminal end portion of the spiral.

2. The antenna according to claim 1, wherein the radio wave absorber is formed into a ring shape.

3. The antenna according to claim 1, wherein the spiral shape of the antenna element is one of a circle and a polygon.

4. The antenna according to claim 1, wherein the radio wave absorber is formed to have one of a polygonal shape and a wavy shape near a center of the spiral.