Mumbai University > Electronics and Telecommunication > Sem3 > Electronic Instruments and Measurements

Marks: 4M

Year: Dec14

• In a Frequency Wave Analyzer, the complex wave to be analyzed is passed through an adjustable attenuator which serves as a range multiplier and permits a large range of signal amplitudes to be analyzed without loading the amplifier

• The output of the attenuator is then fed to a selective amplifier, which amplifies the selected frequency. The driver amplifier applies the attenuated input signal to a High-Q active filter. This High-Q filter is a low pass filter which allows the frequency which is selected to pass and reject all others

• The magnitude of this selected frequency is indicated by the meter, and the filter section identifies the frequency of the component. The filter circuit consists of a cascaded RC resonant circuit and amplifiers

• For selecting the frequency range, the capacitors generally used are of the closed tolerance polystyrene type and the resistances used are precision potentiometers. The capacitors are used for range changing and the potentiometer is used to change the frequency within the selected pass-band.

All told, since the primary function of a wave analyzer is to select an appropriate frequency range and to guide the filters to pass al signals in that range, a Wave Analyzer is also called a Frequency selective voltmeter.