Radio-Frequency Spectrum Analyzers

The resolving power of radio-frequency spectrum analyzers of the continuously tuned type is defined as the width in frequency, at points 3 decibels down, of the trace of a continuous-wave signal. The optimum resolving power is 1.3√F/T, in which F is the frequency band scanned, and T the period of one scan. Traces of pulse-modulated, frequency-modulated, and amplitude-modulated signals are illustrated to show effect of resolving power.