The intermediate frequency in the superheterodyne receiver is chosen as the desired compromise between sensitivity and selectivity. 455kHz is used in AM broadcast applications, while 10.7mHz is used for FM. The IF stage is tuned for a steep skirt passband at that frequency, allowing only the desired heterodyned (shifted) input signal to make it through to the demodulator.
Chat with our AI personalities
Because in radio communication a signal is specified by its frequency, In AM the carrier frequency is fixed.. we cant limit or manipulate it as it will might switch us to another carrier in the atmosphere... manipulating however amplitude (as in FM) doesn't switch us to another channel... so remember in radio communication signal is specified by its frequency whether FM or AM..
A CVT in substations uses it as a communication system. It is also use in filtering high frequency waves that acts as a carrier network.
in the case of communication through gsm technology we transmit our voice frequency to somewhere from the origin. normally human voice frequency lays between 300-3400khz. if all the people tends to transmit their voice, the signal wil be distroyed due to interference. also theoretically it need a very long antenna to transmit a low frequency. therefore it is necessary to modulate each and every signal to a high frequency carrier to transmit without any interference and make possible communication mohamed zawahir +94772260383
To covert a high frequency to a low one, we use flip-flops.
Low, medium and high frequencies is ideal for long distance communication but it is very sensitive to QRM and QRN because only amplitude modulation can be used on this part of the RF spectrum, FM modulation is not possible, where in the higher frequencies, FM (Frequency Modulation) is a beter option but with the drawback of distance overland. VHF, UHF and UUHF can't overcome obstacles like hills, mountains and large buildings, only line of site communication can be used here, although it can be used for long distance in open space IE. in outer space, like satellite communication.