The spectrum analyzer is found in the year 1960s. It is a device which is used to analyze signal amplitude with respect to frequency and is mainly used to measure the power of the spectrum of known and unknown frequency. There are two types of basic analyzers, swept-tuned spectral analyzer and real time spectral analyzer. The spectral analyzer ranges from 500khz to1ghz. When compared to network analyzer, it has less accuracy and it works well in digital modulated signal. It is only a receiver or a single channel. It can be used for scalar components to test amplitude for tracking.


This type of spectrum analyzer is mainly used for RF communication and armature. It is received from radio receiver and it will scan the input by sweeping its LO(local oscillator) to down which converts the input frequency range to fixed intermediate frequency. It is then filtered by RBW( the resolution bandwidth), then it is detected . Swept tuned spectral analyzer is a lower noise floor than real time spectral analyzer.


It is also known as RTSA (real time spectral analyzer). The real time spectrum analyzer technology is derived from the oscilloscope . The noise floor from the real time spectrum is lower than an oscilloscope. It  display frequency distribution  on the x axis and amplitude power on the y axis. The lower IF is more manageable and so it is more effective. This device first collect the information from the time domain , which can be translated  into frequency domain with the help of fast Fourier transform(FFT).


Measurements that can be made by RF spectrum analyzer are

  1. Harmonic measurements.
  2. Inter-modulation .
  3. Satellite antenna alignment.
  4. Return-loss measurements.


The main applications of RF spectrum analyzer are

  • It is mainly used in medical fields
  • Used in industrial instrumentation, radar and oceanography. 
  • It can avoid overloading, distortion and noise.
  • It can be used to  measure the power level of audio frequency.