ABSTRACT
Antennas are used both for transmission and reception. A transmitting antenna converts the high frequency electrical energy supplied to it into electromagnetic energy which is launched or radiated into the space surrounding the antenna. The most fundamental form of antenna is the isotropic radiator. The half-wave dipole is one of the most fundamental types of antenna. The need for very high gain coupled with directional response at UHF or microwave frequencies is often satisfied by the use of a parabolic reflector in conjunction with a radiating element positioned at the feed-point of the dish. Like parabolic reflector antennas, horn antennas are commonly used at microwave frequencies. Connectors provide a means of linking coaxial cables to transmitting/receiving equipment and antennas. Connectors should be reliable, easy to mate and sealed to prevent the ingress of moisture and other fluids. Standing wave ratio is easily measured using an instrument known as an SWR bridge, SWR meter or a combined SWR/power meter.
