Spectrum Analyzer Circuits (SECURE · 2024)

: This is the classic analog approach. It uses a Local Oscillator (LO) to "sweep" through a range of frequencies, mixing them with the incoming signal to produce an Intermediate Frequency (IF) . This IF signal then passes through a narrow-band filter and an amplifier for display.

: Used after the signal has been detected to smooth the display and improve amplitude accuracy by reducing noise. Spectrum Analyzer Circuits

: Determines the analyzer's ability to distinguish between two closely spaced signals. : This is the classic analog approach

: In digital analyzers, the signal is sampled in the time domain, and a computer or microprocessor performs an FFT algorithm to calculate the frequency components. This method is highly attractive for its precision and speed, though it was historically more rare. Key Components & Parameters : Used after the signal has been detected

: The total range of frequencies shown on the horizontal axis, which can be narrowed to "zoom in" on specific signals.