Fig: Block Diagram of Spectrum analyzer.
1. Spectrum analyzer consists of voltage tune oscillator, mixer, IF amplifier, detector, video amplifier, sweep generator and CRT. 2. The input signal applied to the circuit is used with oscillator signal, produces two different frequencies called intermediate frequency. 3. The voltage control oscillator (VCO) swept (toggle) between minimum and maximum frequency linearly. The sawtooth waveform plays important role in controlling the output voltage control oscillator. 4. The IF signal is then amplified by IF amplifier for further processing. 5. The information is signal is detected by detector and further amplified by video amplifiers. Then these signals are fed to the vertical deflecting plate of CRT. 6. The sawtooth waveform also supply signal to horizontal deflecting plates after the amplification. 7. The CRT produces amplitude versus frequency waveform on the screen. 8. In this type the signal are broken down into their individual frequency component.