For a half wave rectifier output signal's frequency is same as that of input.for a half wave rectifier it is DOUBLE that of input.can anyone tell me about a circuit that will make the output frequency HALF OF THE INPUT.use of diode(s) is must.

Yes, the output of a half-wave rectifer circuit yields a signal equal to the inputsignal; while
A full-wave rectifier circuit yield twice the frequency of the input signal.

To obtain a signal proportional to ½ the input signal, you would have to use a 1-stage flip-flop circuit which performs a divide-by-2 function.

What is your circuit application?

A retired Penn State EE in Milton, Delaware