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 for surveying and geological measurement applications.
The choke ring design originated at the Jet Propulsion Laboratory.
Famous quotes containing the words choke and/or ring:
“Most modern reproducers of life, even including the camera, really repudiate it. We gulp down evil, choke at good.”
—Wallace Stevens (1879–1955)
“I started out very quiet and I beat Turgenev. Then I trained hard and I beat de Maupassant. I’ve fought two draws with Stendhal, and I think I had an edge in the last one. But nobody’s going to get me in any ring with Tolstoy unless I’m crazy or I keep getting better.”
—Ernest Hemingway (1899–1961)