The above analysis actually assumes that . Any further increase in the input power or amplifier resistance then causes the gain to fall . As a result, there is always an optimum LO power level and amplifier resistance which gives the highest possible conversion gain. The precise details of these values will depend upon the actual detector. The conversion gain, G , is one of the standard values which tend to be measured and quoted to indicate the performance of a heterodyne or superheterodyne receiver system.
G is called a 'gain' because it is a ratio of an output power to an input power.
It is called a 'conversion' gain because it indicates the relative level of an output which has been converted to a frequency which differs from that of the input. University of St. Andrews, St Andrews, Fife KY16 9SS, Scotland.