Analogue frequency divider with sample and hold circuit - uses frequency divisions suitable for sampling oscilloscopes, synthesisers and electronic musical instruments

摘要

The analogue frequency divider retains the modulation of an input signal, while changing the carrier frequency. It consists of two numerical dividing circuits with fixed dividing factors, a mixing circuit and a sample and hold circuit. The input signal is divided by a factor (N1) in the first divider circuit (1), and then divided by a factor (N2) in the second divider (2). The outputs of the two dividers are fed to a mixer circuit (3), the output F(S) of which is the sum or difference of the two divider outputs. The ratio F(S)/F(in) is N1 (1+-1/N2). F(S) controls a sample and hold circuit (4) which is also fed by the input signal F(in). The output frequency F(out) is related to the input frequency by the ratio F(in)/F(out) =N1 times N2.