An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the power of a signal (a time-varying voltage or current). It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude of a signal applied to its input terminals, producing a proportionally greater amplitude signal at its output. A radio frequency (RF) amplifier design typically optimizes impedance for power transfer, while audio and instrumentation amplifier designs normally optimize input and output impedance for least loading and highest signal integrity.
An antenna is an array of conductors (elements), electrically connected to the receiver or transmitter. Antennas can be designed to transmit and receive radio waves in all horizontal directions equally (omnidirectional antennas), or preferentially in a particular direction (directional, or high-gain, or “beam” antennas). An antenna may include components not connected to the transmitter, parabolic reflectors, horns, or parasitic elements, which serve to direct the radio waves into a beam or other desired radiation pattern.
VSAT stands for Very Small Aperture Terminal, and refers to the physical size of the parabolic reflector antenna. However, the term VSAT is generally used across the industry to describe any fixed satellite terminal that provides one-way or two-way communications. The actual size of the dish is dependent upon factors such as the frequency of operation, strength of the satellites' transmissions, and its use as either a one-way or two-way terminal. VSAT networks typically operate at one of three frequencies: C band, Ku band, or Ka band.