Choke ring antenna
A choke ring antenna is a particular form of omnidirectional antenna for use at high frequencies. It consists of a number of conductive concentric cylinders around a central antenna. Due to its delicate construction, it is often enclosed in a protective cover or radome when placed outside and exposed to the elements.
Choke ring antennas are notable for their ability to reject multipath signals from a source. Since the path that a signal takes from a transmitter to receiver can be used to measure the distance between the two, this makes it highly suited for GPS and radar applications. In a GPS ground-based receiver, a choke ring antenna can provide millimeter precision measurements[2] for surveying and geological measurement applications.
The choke ring design originated at the Jet Propulsion Laboratory.[3]
See also
- Trimble Navigation - one manufacturer of this product.
- Patch antenna - another antenna for GPS applications.
- Magellan Professional Products - another manufacturer of this product.
Notes
- US Patent 6,040,805 - Patent for Low Profile Ceramic Choke , one specific type of choke ring antenna.
- http://www.trimble.com/Infrastructure/Trimble-Choke-Ring-Antenna.aspx - Catalog page for a Trimble choke ring antenna.
- http://www.javad.com/jns/technology/Single-Depth%20Low-Multipath%20Choke%20Ring.html - A basic description of choke ring antenna benefits and limitations.
External links
- http://www.javad.com/jns/technology/Choke%20Ring%20Theory.html - Basic choke Ring theory of operation.