Communications Technology Handbook, 2nd Edition

30 Radio frequency receivers

The major aim of any communications system must be to ensure the highest level of fidelity of the signals received at a distance, over any transmission medium. The receiver is thus the final and most important element in the chain, to ensure the accurate and near error free transmission of information. (See also Noise, p. 232.) The major requirements of any receiver can therefore be summarised as follows:

(1)  to select the wanted signal from the many others present in any given waveband;

(2)  to recover the information from the modulated wave;

(3)  to present the information in a suitable manner, e.g. audio, video, data, etc.;

(4)  To carry out these functions without degrading the received signal to noise (S/N ...