||This article does not cite any sources. (December 2009)
In physics, field strength (also signal strength) means either the magnitude of a vector-valued field (e.g., in volts per meter, V/m, for an electric field E) or its square, the intensity (in watts per square meter, W/m2, for E as above). For example, electromagnetic field results in both electric field strength and magnetic field strength. As an application, in radio frequency telecommunications, the signal strength excites a receiving antenna and thereby induce a voltage at a specific frequency and polarization in order to provide an input signal to a radio receiver. Field strength meters are used for such applications as cellular, broadcasting, wi-fi and a wide variety of other radio-related applications.