What is the difference between low level and high level AM?
At the output of the modulator we get the AM wave. The low level transmitter circuit does not require a large AF modulator power so its design is simplified. However the overall efficiency is much lower compared to high level modulation. This is due to the use of less efficient linear amplifiers.
What is high level modulation?
High level modulation occurs when the modulating voltage is applied to the collector/plate circuit of the final power amplifier. With high level modulation, the final stage is operated class C and the preceding stages are also operated class C. The overall efficiency of such a transmitter is very high.
What is a low level AM modulator?
Low level modulator: A low level AM modulator would be one where the modulation is applied to low power stage of the transmitter, typically in the RF generation stages, or via the digital signal processing areas. The drawback of this approach is that linear amplification is required for the RF stages.
What is high level Amplitude Modulation?
In High level Amplitude Modulation system, Modulation is done at high power of carrier and modulating signals so Power amplifiers are used to boost the carrier and modulating signals before modulation. Collector modulation method is the example of High level Amplitude Modulation.
What do you understand by low level AM?
low-level modulation: Modulation of a signal, e.g., a carrier, at a point in a system or device, such as a radio transmitter, where the power level is low compared to the final output power. (
What is the difference between DSB SC and SSB SC?
DSB-SC is double sideband suppressed carrier modulation and SSB-SC is single sideband suppressed carrier modulation. When amplitude modulation is carried out, the modulating signal spectrum is shifted to the carrier frequency band. SSB-SC is DSB-SC with only one side band.
What is the cause of over modulation?
When the input telecommunication exceeds the required value, it results in over modulation. Over modulation can take place in both AM and FM systems.
Do you understand by low level AM?
9. What do you understand by low level AM? Explanation: In low level AM, modulation is done at low power of carrier and modulating signal therefore output power is low.
What is the advantage of low level modulation?
An advantage of low level modulation is that less modulating signal power is required to achieve a high percentage of modulation.
What is the principle of amplitude modulation?
Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave. In amplitude modulation, the amplitude (signal strength) of the carrier wave is varied in proportion to that of the message signal, such as an audio signal.
What’s the difference between low and high level modulation?
High level modulation is when amplitude modulation is applied to a RF power amplifier, so the modulator has to supply half of the carrier power. In low level modulation, modulation takes place prior to the output element of the final stage of the transmitter. For low level AM modulator class A amplifier is used.
How is a low level AM transmitter similar to a high level transmitter?
The low-level AM transmitter shown in the figure (b) is similar to a high-level transmitter, except that the powers of the carrier and audio signals are not amplified. These two signals are directly applied to the modulated class C power amplifier.
Where does modulation take place in an AM transmitter?
They’re easy to identify: A low level AM transmitter performs the process of modulation near the beginning of the transmitter. A high level transmitter performs the modulation step last, at the last or “final” amplifier stage in the transmitter. Each method has advantages and disadvantages, and both are in common use.
Why are transistorized modulator circuits used for low level modulators?
The amplitude modulated signal is then transmitted using transmitting antenna. The transistorized modulator circuits can be used for low level modulator due to the low power which is to be handled. The low level transmitter circuit does not require a large AF modulator power so its design is simplified.