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:
“Now ‘tis the spring, and weeds are shallow-rooted;
Suffer them now, and they’ll outgrow the garden,
And choke the herbs for want of husbandry.”
—William Shakespeare (1564–1616)
“I started out very quiet and I beat Mr. Turgenev. Then I trained hard and I beat Mr. de Maupassant. I’ve fought two draws with Mr. Stendhal, and I think I had an edge in the last one. But nobody’s going to get me in any ring with Mr. Tolstoy unless I’m crazy or I keep getting better.”
—Ernest Hemingway (1899–1961)