Browse Prior Art Database

HIGH FREQUENCY WHIP ANTENNA (800 MHz)

IP.com Disclosure Number: IPCOM000005607D
Original Publication Date: 1986-Oct-01
Included in the Prior Art Database: 2001-Oct-18
Document File: 2 page(s) / 81K

Publishing Venue

Motorola

Related People

Timothy L. Higby: AUTHOR [+2]

Abstract

The Whip Antenna was developed to satisfy a market trend toward smaller, downsized portable products. It is the intention of this report to explain its design, construction and to set apart similar or previous concepts.

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MOTOROLA Technical Developments Volume 6 October 1986

HIGH FREQUENCY WHIP ANTENNA (800 MHz)

by Timothy L. Higby and Donald Beaumont

The Whip Antenna was developed to satisfy a market trend toward smaller, downsized portable products. It is the intention of this report to explain its design, construction and to set apart similar or previous concepts.

   The antenna is made-up of six parts. The first is called a cdupling. It is a die cast part made from a zinc alloy more commonly known as Zamak-3. Before the casting operation, speedometer cable material along with a nylon ring, is placed into the die casting tool. Hot molten zinc is cast around it, flowing in and around the speedometer cable windings, consistently providing a strong, integral assembly. This part is then copper-nickel plated and selective gold is applied at the tip for good conductivity. (see fig. 1).

   The coupling assembly then has glass filled polypropylene over molded around it. Polypropylene was selected because of its low dielectric constant (see fig. 2). Next, a Buna-N o-ring, (to seal the internal air gaps from being filled with polyurethaneduring the next molding operation) conductiveelastomer(madefrom silicone and impregnated with silverized particles) along with a stainless steel retainer, is assembled and captivated by a "c" type retaining ring.

   The final step in the construction of this antenna is to over mold polyurethane around the entire part. The nylon ring travels along the length o...