Advantages of Foster Seeley Discriminator | Disadvantages of Foster Seeley Discriminator
This page covers advantages and disadvantages of Foster Seeley Discriminator and its basics. It mentions benefits or advantages of Foster Seeley Discriminator and drawbacks or disadvantages of Foster Seeley Discriminator.
There are different types of modulation and demodulation techniques such as amplitude, phase and frequency. There are various techniques used as frequency demodulators or detectors which include quadrature detector, slope detector, PLL detector, foster seeley discriminator, ratio detector, DSP based FM demodulator etc.
What is Foster Seeley Discriminator?
It is used as FM detector to demodulate frequency modulated signal. It is used as AFC (Automatic Frequency Control) in receivers such as super-heterodyne.
The figure depicts the circuit diagram of Foster Seeley Discriminator. The circuit is similar to full wave bridge rectifier with center tapped transformer. It uses tuned version of transformer to convert frequency changes into amplitude changes. As shown transformer is tuned to desired carrier frequency and it is interfaced with rectifier diodes. The components such as RF choke, C1 and C2 provide blocking of RF signal so that it does not appear at the output.
Benefits or advantages of Foster Seeley Discriminator
Following are the benefits or advantages of Foster Seeley Discriminator:
➨It provides good amount of performance.
➨It offers fair amount of linearity.
➨It is simple to implement with the use of components.
➨It delivers high output in comparison to ratio detector.
➨It provides output with low distortion in comparison to ratio detector.
Drawbacks or disadvantages of Foster Seeley Discriminator
Following are the drawbacks or disadvantages of Foster Seeley Discriminator:
➨It is difficult to incorporate this circuit in the IC.
➨It is expensive due to higher cost of the transformer required.
➨It has narrow bandwidth in comparison to ratio detector.
➨Limiter is required along with foster seeley discriminator as it is sensitive to frequency and amplitude variations.