Front-to-back ratio

In telecommunication, the term front-to-back ratio (also known as front-to-rear ratio) can mean:

1. The ratio of power gain between the front and rear of a directional antenna.
2. Ratio of signal strength transmitted in a forward direction to that transmitted in a backward direction. For receiving antennas, the ratio of received-signal strength when the antenna is rotated 180°.^[1]

This refers to when an antenna, the gain in a specified direction, i.e., azimuth, usually that of maximum gain, compared to the gain in a direction 180° from the specified azimuth. A front-to-back ratio is usually expressed in dB.

In other electrical engineering the front to back ratio is a ratio of parameters used to characterize rectifiers or other devices, in which electrical current, signal strength, resistance, or other parameters, in one direction is compared with that in the opposite direction.

References

•  This article incorporates public domain material from the General Services Administration document "Federal Standard 1037C" (in support of MIL-STD-188).