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In telecommunications, desensitization (also known as receiver blocking) is a form of electromagnetic interference where a radio receiver is unable to receive a weak radio signal that it might otherwise be able to receive when there is no interference.
LC circuits are often used as filters; the Q ("Quality" factor) determines the bandwidth of each LC tuned circuit in the radio. The L/C ratio, in turn, determines their Q and so their selectivity, because the rest of the circuit - the aerial or amplifier feeding the tuned circuit for example - will contain present resistance.
In telecommunications, the free-space path loss (FSPL) (also known as free-space loss, FSL) is the attenuation of radio energy between the feedpoints of two antennas that results from the combination of the receiving antenna's capture area plus the obstacle-free, line-of-sight (LoS) path through free space (usually air). [1]
There are several factors that affect this: Free-space path loss: This is the fundamental loss that occurs due to the spreading of the radio wave as it propagates through space. [ 2 ] It follows an inverse square law, meaning the signal strength decreases proportionally to the square of the distance between the transmitter and receiver.
The term radio receiver is understood in this article to mean any device which is intended to receive a radio signal in order to generate useful information from the signal, most notably a recreation of the so-called baseband signal (such as audio) which modulated the radio signal at the time of transmission in a communications or broadcast system.
The loss resistance will generally affect the feedpoint impedance, adding to its resistive component. That resistance will consist of the sum of the radiation resistance R rad and the loss resistance R loss. If a current I is delivered to the terminals of an antenna, then a power of I 2 R rad will be radiated and a power of I 2 R loss will be ...
The loss resistance is in series with the radiation resistance, and as the length decreases the loss resistance only decreases in proportion to the first power of the length (wire resistance) or remains constant (contact resistance), and hence makes up an increasing proportion of the feedpoint resistance. So with smaller antenna size, measured ...
The sensitivity of a microphone is usually expressed as the sound field strength in decibels (dB) relative to 1 V/Pa (Pa = N/m 2) or as the transfer factor in millivolts per pascal (mV/Pa) into an open circuit or into a 1 kiloohm load. [citation needed] The sensitivity of a loudspeaker is usually expressed as dB / 2.83 V RMS at 1 metre.