Antenna Authority, Inc
Phone (770) 577-7969





Product Code --- CBS-12
Cavity Backed Spiral
downloadable pdf file


This self-complementary Archimedean spiral antenna is a frequency independent antenna. It is a lightweight medium-gain array designed to receive a circularly polarized wave.  The Archimedes spirals typically cover a 10 to 1 frequency range while maintaining essentially constant impedance over the band.  The circularly polarized antennas have been designed for broad-beam, broadband applications and provide a compact, lightweight antenna configuration which can be easily flush mounted. They are widely used in systems whose primary functions are surveillance, direction finding and telemetry.  This Spiral antenna is mounted in a square structure and made on FR4 .063 fiberglass with a flat front face that can be easily mounted in the side of a vehicle.   It is terminated and loaded with absorbing foam.  Its low frequency is a function of the size and depth of the cavity, while the upper frequency is limited by the detail of the center structure.  It has greater than a 10 dB F/B ratio before mounting into a vehicle. 

Electrical Specifications

Frequency Coverage:   300 MHz 3.2 GHz
Azimuths Coverage:   80 beam width typical for 3 DB down
Antenna:   4-element log-periodic dipole array
Gain:    -1.5 to + 3 dBi
Polarization:  CBS-12-R   Right Hand Circular
Polarization:  CBS-12-L   Left Hand Circular
Impedance:     50 ohms nominal
Connectors   BNC

Mechanical Specifications      





downloadable pdf file

  Width: 12" - Length : 12" - Thick: 5

5 Lbs

Operating: -20C to +60C Storage: -40C to +70C Humidity:95%

Aluminum, FR-4, Foam
Stable rugged construction, compact, light weight. Works in harsh conditions


24" version available
Refurbished 24" available

Gain and Pattern Plots

Pictures of Typical Construction

Antennas are available with either square cavities for individual use, or with angled sides for mounting in a circular array.

12" Frequency range - 300 MHz to 3.2 GHz

PDF Printable Brochure

Specifications subject to change without notice
Printed in U.S.A. Copyright 6/1/2008

Antenna Authority offers a wide assortment of directional, wideband antennas and other equipment used for radio direction finding and Geo location. We are experts in covert antennas, vehicles and their operation. We are also ready to design new products to meet your specific needs.

Antenna Authority, Inc.                Ferrel Bentley - E-Mail
3381 W. County Line Road
Douglasville, Ga. 30135-1145
(770) 577-7969
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