Intermediate Frequency Amplifier: Choice of frequency: The Intermediate Frequency Amplifier (IF) of a receiving system is usually a compromise, since there are reasons why it should be neither low nor high, nor in a certain…
Frequency Changing and Tracking in Receivers: The mixer is a nonlinear device having two sets of input terminals and one set of output terminals. The signal from the antenna or from the preceding RF amplifier…
Transistor RF Amplifier Circuit: A radio receiver always has an RF section, which is a tunable circuit connected to the antenna terminals. It is there to select the wanted frequency and reject some of the…
Superheterodyne Principle: The block diagram of Figure 6-2 shows a basic superheterodyne receiver. In the Superheterodyne Principle, the incoming signal voltage is combined with a signal generated in the receiver. This local oscillator voltage is…
Tuned Radio Frequency Receiver: The Tuned Radio Frequency Receiver is a simple "logical" receiver. A person with just a little knowledge of communications would probably expect all radio receivers to have this form. The virtues…
Generation of Frequency Modulation: The Generation of Frequency Modulation system is a variable output frequency, with the variation proportional to the instantaneous amplitude of the modulating voltage. The subsidiary requirements are that the unmodulated frequency…
Noise and Frequency Modulation: Noise and Frequency Modulation is much more immune to noise than amplitude modulation and is significantly more immune than phase modulation. In order to establish the reason for this and to…
Theory of Frequency Modulation and Phase Modulation: Frequency Modulation and Phase Modulation is a system in which the amplitude of the modulated carrier is kept constant, while its frequency and rate of change are varied…
Extensions of Single Sideband Amplitude Modulation: The Extensions of Single Sideband Amplitude Modulation is namely, Forms of Amplitude Modulation: This section on amplitude modulation defines, describes and lists the main applications of the various forms of…
Methods of Suppressing Unwanted Sidebands: As stated earlier, the three practical methods of SSB generation all use the balanced modulator to suppress the carrier, but each uses a different method of removing the unwanted sideband.…
