There are many functional control button on the spectrum analyzer panel, which are used to control and adjust the system function. The most important part which influence the signal reaction is filter bandwidth. The feature of the filter is Gaussian-Shaped Filter. Resolution Bandwidth represent two different frequency signal the lowest bandwidth difference. If the two signal bandwidth are lower than the RBW of the spectrum analyzer, the two signal will be overriding. So the proper RBW is the key concept for the correct use of the spectrum analyzer.