To hear a radio 100 of miles away from the source when the frequency is 1000kc it would require antenna of tremendous size and bulk. So the idea is to transmit a very hi frequency and vary that frequency by 1000kc and then get rid of the carrier frequency and hear the modulation frequency only or 1000kc in this example.
Qam only
Methods of amplitude modulation can be put in the two categories namely Linear modulation methods and Square law modulation methods. Linear modulation method utilizes the linear region of the current voltage characteristics of the amplifying device that is transistor or electron tube. Square law modulation method utilizes the square law region of some current voltage characteristics of a diode or transistor or electron tube. A large number of linear modulation methods have been devised and have been used to varying degree. These methods are namely linear shunt plate modulation or anode choke modulation, linear series plate modulation, grid bias modulation, cathode modulation, suppressor grid modulation, screen grid modulation, collector modulation. Square law modulation circuits make use of non linear current voltage characteristics of diodes or triodes and are in general suited for use at low voltages. Important square law modulation methods are square law diode modulation and balanced modulator.
due to velocity modulation density modulation occurs in TWT
Modulation index is also called as Modulation depth. The modulation index of a modulation scheme describes by how much the modulated variable of the carrier signal varies around its unmodulated level.
presentation of analog digital hybrid modulation
"Base band", meaning that no modulation is used."Base band", meaning that no modulation is used."Base band", meaning that no modulation is used."Base band", meaning that no modulation is used.
Adaptive delta modulation is used in audio communication systems to avoid the two drawback of delta modulation.
pulse code modulation method used a telephony.
Adaptive delta modulation is used in audio communication systems to avoid the two drawback of delta modulation.
If you speak loudly then softly you have used modulation of your voice
It is used to delay the modulation
Actually phase modulation was used for the color signal in all analog TV systems.Phase modulation, with some signal preprocessing, was used to indirectly get frequency modulation in many FM transmitters.Certain modems use phase amplitude modulation.etc.
Actually phase modulation was used for the color signal in all analog TV systems.Phase modulation, with some signal preprocessing, was used to indirectly get frequency modulation in many FM transmitters.Certain modems use phase amplitude modulation.etc.
pulse position modulation, used in many RC model aircraft controls.
Amplitude Modulation (AM) is used for the picture portion of a television transmission while Frequency Modulation (FM) is used for the audio portion.
amplitude modulation is used
Modulation Index is the ratio of the maximum deviation frequency to the frequency of modulation. In other words it is the ratio of the spread in frequency spectrum to the frequency that was used to modulate the carrier. For FM, modulation index is given by the formula mf= df/f where, mf=modulation index for FM df=difference in carrier frequency f=frequency of the signal