Frequency modulation - Wikipedia
Phase Modulation (PM) – amount of phase change on angle of The relationship for an FM signal generated signal . Typical receiver capture ratio is 1 dB. describes difference between amplitude modulation,frequency modulation and phase of SSB modulation is difficult and it is complex in detection at receiver. Know the relationship of carrier frequency, modulation frequency and Receiver : The sub-system that takes in the transmitted signal from the channel and vary one of the three parameters of the signal: amplitude, frequency or phase.
Radio Modulation Types | Modulation Techniques | jogglerwiki.info
When a modulating signal has more than one frequency, two sideband frequencies are produced by every frequency. The sidebands of frequencies present above the carrier frequency will be the same as the ones presented below. The sideband frequencies present above the carrier frequency is known to be the upper sideband and all those below the carrier frequency belong to the lower sideband.
The USB frequencies represent the some of the individual modulating frequencies and the LSB frequencies represent the difference between the modulating frequency and the carrier frequency. The total bandwidth is represented in terms of the higher modulating frequency and is equal to twice this frequency. Modulation Index m The ratio between the amplitude change of carrier wave to the amplitude of the normal carrier wave is called Modulation index.
It can also be defined as the range in which the amplitude of the carrier wave is varied by the modulating signal. Another way of expressing the modulation index is in terms of the maximum and minimum values of the amplitude of the modulated carrier wave.
A phase-locked loop can be used as an FM demodulator.
Slope detection demodulates an FM signal by using a tuned circuit which has its resonant frequency slightly offset from the carrier. As the frequency rises and falls the tuned circuit provides a changing amplitude of response, converting FM to AM.
AM receivers may detect some FM transmissions by this means, although it does not provide an efficient means of detection for FM broadcasts.
The Many Types of Radio Frequency Modulation
Applications[ edit ] Magnetic tape storage[ edit ] FM is also used at intermediate frequencies by analog VCR systems including VHS to record the luminance black and white portions of the video signal.
Commonly, the chrominance component is recorded as a conventional AM signal, using the higher-frequency FM signal as bias.
FM also keeps the tape at saturation level, acting as a form of noise reduction ; a limiter can mask variations in playback output, and the FM capture effect removes print-through and pre-echo.
All the modulation types are used to transmit information from one place to the distant place.
Mostly this techniques are employed in wireless communication. For any analog modulator type, there are two inputs and one output. The two inputs are modulating signal i. The output is referred as modulated waveform.
Amplitude Modulation AM Amplitude Modulation AM is the modulation technique in which carrier amplitude varies based on analog baseband information signal to be transmitted using wireless device. AM broadcast signals are mainly propagated by ground waves during the day and by sky waves at night time. Advantages, disadvantages and applications of AM Different amplitude modulation techniques have their own advantages and disadvantages as mentioned below:
- Home of RF and Wireless Vendors and Resources
- amplitude modulation vs frequency modulation vs phase modulation
- Basic types of modulation