Antenna Dictionary

Cable: An assembly of one or more insulated conductors, or optical fibers, or a combination of both, within an enveloping jacket. A cable is constructed so that the conductors or fibers may be used singly or in groups. Certain types of communications cables, especially long submarine cables but also terrestrial cables, whether the communications media are metallic or optical fiber, may contain metallic conductors that supply power to repeaters (amplifiers). Vendors that Manufacture Wire and cable.

Cable assembly: A cable that is ready for installation in specific applications and usually terminated with connectors. [Cable assembly manufacturers]

Cable connectors: Fittings for cable ends which permit rapid connection and disconnection with equipment or other cables. [Cable connector manufacturers]

Cage Antenna. An antenna with a number of parallel line arrange into a shape of a cage.

Capacitance: A natural property of an electrical circuit which opposes the rate of change of voltage. See Capacitor Terms.

Capacitor: A device for storing an electrical charge. Also refer to Dictionary of Capacitor terms, or List of Capacitor manufacturers.

Capacitor Antenna. Text in review.

Capture Effect: A phenomenon, associated with FM reception, in which only the stronger of two signals at or near the same frequency will be demodulated.

Carrier Power: The average power supplied to the antenna transmission line by a transmitter during one radio frequency cycle taken under the condition of no modulation.

Cassegrain antenna: An antenna in which the feed radiator is mounted at or near the surface of a concave main reflector and is aimed at a convex secondary reflector slightly inside the focus of the main reflector. Energy from the feed unit illuminates the secondary reflector, which reflects it back to the main reflector, which then forms the desired forward beam. The Cassegrain antenna design is adapted from optical telescope technology and allows the feed radiator to be more easily supported.

Cassegrain Feed. A main reflector that uses a feed pointed at a small reflector at the end of a waveguide that reflects back to the main antenna reflector.

Cellular Communications: A cellular communications area is divided into smaller areas, called cells, and transmissions are passed from cell to cell until they reach their final destinations. Each cell must contain an antenna and transmission facilities to pick up signals from another cell or from a caller and to pass those signals on to an adjacent cell or to a caller within the cell. Cells can be anywhere from a few kilometers to 32 kilometers in diameter.

Center-fed: [Current Feed] Transmission line connection at the electrical center of an antenna radiator. Connecting the center of an antenna to a transmission line which is then connected to the final (output) stage of the transmitter.

Chrome Coil Antenna: -- Text in review.

Chrome Nut Antenna: -- Text in review.

Circuit noise level: At any point in a transmission system, the ratio of the circuit noise at that point to an arbitrary level chosen as a reference. Note: The circuit noise level is usually expressed in dBrn0, signifying the reading of a circuit noise meter, or in dBa0, signifying circuit noise meter reading adjusted to represent an interfering effect under specified conditions.

Circular Antenna. A half wave antenna in the shape of a circle.

Circular Polarization: In electromagnetic wave propagation, polarization such that the tip of the electric field vector describes a helix. The magnitude of the electric field vector is constant. The projection of the tip of the electric field vector upon any fixed plane intersecting, and normal to, the direction of propagation, describes a circle. A circularly polarized wave may be resolved into two linearly polarized waves in phase quadrature with their planes of polarization at right angles to each other. Circular polarization also referred to as "right-hand" or "left-hand," depending on whether the helix describes the thread of a right-hand or left-hand screw, respectively.

Circularly Disposed Dipole Array: See Wullenweber Antenna.