Ambient Temperature - The prevailing temperature in the immediate vicinity of an object.

dBi - Decibels of gain relative to an isotropic antenna, or one that radiates equal power in all directions; used to measure antenna gain.

dBm – An Abbreviation for decibels above (or below) 1 milliwatt. A quantity of power expressed in terms of its ratio to 1 milliwatt.

Downlink - A satellite-to-earth microwave channel- and related components, such as the base station receiving equipment.

Gain - The product of the gain of an active device and a specified bandwidth.

Guard Band - The unused bandwidth separating channels to prevent crosstalk.

I/O Modules - General-purpose circuit modules that interface a microprocessor to relays, switches, and transducers.

Intermodulation - Mixing of two radio signals to produce a third signal that interferes with the reception of a desired signal.

Pass Band Ripple - fluctuations, or variations, in the frequency magnitude response within the pass band of a filter. Passband ripple, measured in dB

Transmission - The dispatching of a signal, message, or other form of intelligence by wire, radio, telegraphy, telephony, facsimile, or other means; the signaling of data over communications channels.

Uplink - The earth station electronics and antenna that transmit information to a communication satellite for relay back to the ground.

VSWR -Abbreviation for voltage standing-wave ratio.

Voltage Standing-Wave Ratio – Abbreviated VSWR. In a stationary-wave system (such as in a waveguide or coaxial cable), the ratio of the amplitude of the electric field or voltage at a voltage maximum to that at an adjacent voltage minimum.