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There are three major types of modulation:
AM, Amplitude Modulation, where the modulation signal is altering the amplitude of the carrier according to its own amplitude, normally this is done in the output stage. Therefor a strong audio signal is necessary at the same or a little less than the power of the carrier, never higher, because that will over modulate the carrier that will resort in distortion of the receiver output. AM is used in the lower band of the RF spectrum.
FM, Frequency Modulation, where the frequency of the carrier is altered by the audio signal. When the amplitude of the audio is going higher the frequency go lower. Modulation happen at the oscillator stage, therefor a small audio signal is used to modulate the frequency. FM is normally used in the higher frequency range of the RF spectrum, 50MHz and up.
FSK, Frequency-shift keying, used for data transmission, this type of modulation is simply, switching the carrier on and of, a high bit will switch the oscillator on and a low bit will switch it off, in some designs a low will be on and a high off.
What else can I help you with?
Why is the intelligence signal not in the AM envelope?
The intelligence signal is in the AM envelope.In AM modulation, the carrier is amplitude modulated by the signal. This signal appears as the envelope of the carrier. You can demodulate it by following the peaks on each cycle of the carrier. You can either follow the positive peaks or the negative peaks - it does not matter if the original modulation is symmetrical.
Would the linear combination of a low frequency intelligence signal and a high frequency carrier signal be effective as a radio transmission?
Yes, a linear combination of a low-frequency intelligence signal and a high-frequency carrier signal can be effective for radio transmission. This method, known as amplitude modulation (AM) or frequency modulation (FM), allows the low-frequency signal to be transmitted over longer distances by utilizing the high-frequency carrier wave. The carrier wave effectively "carries" the information, enabling it to be received and demodulated by appropriate receivers. This technique is fundamental in broadcasting and communication systems.
Is there an intelligence frequency in the am signal?
In the context of AM (Amplitude Modulation) radio signals, "intelligence" refers to the audio or information being transmitted, such as music or voice. This intelligence is conveyed by varying the amplitude of the carrier wave at specific frequencies within the AM band, typically ranging from 530 to 1700 kHz. The modulation process encodes the audio signal onto the carrier frequency, allowing it to be transmitted and received. Therefore, while there is no distinct "intelligence frequency," the information is embedded within the modulation of the carrier wave across the AM spectrum.
What is message signal in amplitude modulation?
In amplitude modulation (AM), the message signal is the original audio or information signal that contains the content to be transmitted, such as voice, music, or data. This signal is typically a low-frequency waveform that varies in amplitude. The message signal modulates the amplitude of a higher frequency carrier wave, which translates the information for efficient transmission over long distances. The result is a modulated wave that carries the original message signal within its amplitude variations.
Why carrier signal is always in analog signal?
It isn't always. Baseband analog signals have no carrier.
Why is the intelligence signal not in the AM envelope?
The intelligence signal is in the AM envelope.In AM modulation, the carrier is amplitude modulated by the signal. This signal appears as the envelope of the carrier. You can demodulate it by following the peaks on each cycle of the carrier. You can either follow the positive peaks or the negative peaks - it does not matter if the original modulation is symmetrical.
Could Light be used as carrier for intelligence signal?
Absolutely
What do modem stand for?
MODEM stands for MOulator/DEModulator. It is a device that translates a data bit stream from a digital device into a modulation signal and modulates a carrier for transmission over wires. Since it can also receive data streams it must be able to demodulate the carrier and translate the modulated intelligence back into a data bit stream.
What extracts the intelligence from a high frequency carrier in FM receivers?
One method to extract the intelligence (signal) from a high frequency carrier in FM receivers is with a phase locked loop.
How does a modem work on osi physical layer?
Modem (from modulator-demodulator) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. That is the definition of Layer 1.
How the modem change the analog signal?
MODEM stands for modulator/demodulator. Outgoing it modulates a carrier wave with information and transmits this data on a wire or through the air. When it receives a modulated signal it demodulates the signal and separates out the information.
What a modems used for?
A modem is a modulator and demodulator device that modulates the analog carrier signal to encode the digital information and demodulates the signal to decode the transmitted information. The modem usually produces a signal that can be transmitted easily and decoded to reproduce the original data.
What are 'definitions'?
aural modulator used to extend the audio information and aural modulator also modulates visual carrier signal.
What are the parameters of high frequency carrier that may be varied by a lower frequency intelligence?
Following are the 3 parameter by which high Frequency carrier can be varied by low frequency intelligence signal 1) Amplitude 2) Phase 3) Frequency
What does a radio wave transform radio waves into?
Sound.More informationAfter a modulated carrier signal has been received through the radio's aerial, the radio de-modulates it to release the live sound as picked-up from microphones in the radio studio (or was taken from recordings), which was then used to modulate the carrier signal at the transmitter.De-modulation that is done by a radio receiver can be described very simply as "removing the carrier signal to produce the sound".
What does a radio transform waves into?
Sound.More informationAfter a modulated carrier signal has been received through the radio's aerial, the radio de-modulates it to release the live sound as picked-up from microphones in the radio studio (or was taken from recordings), which was then used to modulate the carrier signal at the transmitter.De-modulation that is done by a radio receiver can be described very simply as "removing the carrier signal to produce the sound".
Would the linear combination of a low frequency intelligence signal and a high frequency carrier signal be effective as a radio transmission?
Yes, a linear combination of a low-frequency intelligence signal and a high-frequency carrier signal can be effective for radio transmission. This method, known as amplitude modulation (AM) or frequency modulation (FM), allows the low-frequency signal to be transmitted over longer distances by utilizing the high-frequency carrier wave. The carrier wave effectively "carries" the information, enabling it to be received and demodulated by appropriate receivers. This technique is fundamental in broadcasting and communication systems.
