a converter for digital radio applications , consisting of a parallel analogue to digital converter that provides a sampling at signal carrier frequency , or preferably at a harmonic of this frequency . successive samples are stored in a memory and this is accessed at a lower rate to average numbers of samples . the adc achieves greater resolution by virtue of this sampling . filtering is provided by averaging action , but further filtering functions can be performed by an add - on filter . the converter receives modulated analogue signal from an input stage , for example the rf . or if . circuit of a radio receiver . in a modified version of the apparatus , several converters may be utilized in parallel to afford increased data colletion .