Choke Ring

For fixed GPS antenna installations where high accuracy is of the upmost concern then fitting a choke ring underneath the antenna provides a significant improvement in performance.

A choke ring antenna consists of a number of conductive concentric cylinders around a central antenna.

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 applications. In a GPS ground based receiver, a choke ring antenna can provide millimeter precision measurements for surveying and geological measurement applications.