Browse Prior Art Database

Antenna

IP.com Disclosure Number: IPCOM000049323D
Original Publication Date: 1982-Apr-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 2 page(s) / 165K

Publishing Venue

IBM

Related People

Slavetsky, EJ: AUTHOR [+2]

Abstract

An antenna having improved broadband frequency coverage is constructedd by combining both circular and square interleaved conductor spirals on a substrate. Conductors in the transition portion are increased in width at the corners between the circular and square antennas to equal exposed substrate area and maintain constant circuit impedance over the frequency range.

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Antenna

An antenna having improved broadband frequency coverage is constructedd by combining both circular and square interleaved conductor spirals on a substrate. Conductors in the transition portion are increased in width at the corners between the circular and square antennas to equal exposed substrate area and maintain constant circuit impedance over the frequency range.

Referring to the figure, a pair of interleaved, printed conductors of varying line width are wound in a substantially circular configuration 1 near the center of the substrate. These conductors are then formed in a substantially square configuration 2 at the outer edges of the planar substrate. The transition portions 3 of the conductors connecting the circular and square designs are formed by varying their widths, as at 4, to maintain the exposed substrate area equal to the area covered by the conductors.

Line termination is accomplished by forming substrate extensions normal to the substrate surface at the edges of the square onto which the spiral windings continue. The edge windings are then covered with a molded lossy dielectric 5. This manner of terminating eliminates the need to place the attenuating material on the outer turns of the planar circuit which would thereby severely limit the lowest frequency of operation.

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