In radio transmission, transmitter power output (TPO) is the actual amount of power (in

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s) of

radio frequency Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the u ...

(RF) energy that a

transmitter In electronics and telecommunications, a radio transmitter or just transmitter (often abbreviated as XMTR or TX in technical documents) is an electronic device which produces radio waves with an antenna (radio), antenna with the purpose of sig ...

produces at its output. TPO is a concept related to effective radiated power (ERP), but refers to the power output of a transmitter, without accounting for antenna gain. The ERP for VHF/UHF transmitters is normally more than the TPO, for LF/MF transmitters it has nearly the same value, while for VLF transmitters it may be less.

Signal formula

The radio antenna's design focuses the

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, creating gain and increasing the ERP. There is also some loss (negative gain) from the feedline, which reduces some of the TPO to the antenna by both resistance and by radiating a small part of the signal. The basic

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relating transmitter to effective power is: ::

TPO\ \times\ loss_\ \times\ gain_\ =\ ERP

Note that in this formula the Antenna Gain is expressed with reference to a dipole ( dBd)

Signal formula

References

See also