Certain pratical guidelines and design methods for getting optimal characteristics in frequency multipliers are considered

and one of the frequency multiplying circuits in atomic frequency standards is given. The phase drift at the 90MHz output of the （ × 18） frequency multiplier is measured with a phase drift measurment set-up made during the study. The results show that phase drift Δφ = 14° when the ambient temperature varies from 30℃ to 50℃; Δφ=4.7 when the supply-voltage varies from 20V to 22V. The phase noise in our multiplier is also measured with another multiple-period measurement set-up with single sideband mixing designed by authors. Results show that the fractional frequency error due to phase noise in the multiplier is 1.1×10-12 when the averaging time τ = 1 sec.

the fractional error is 3.9×10-13 when the averaging time τ= 10 sec.

A simple method of single sideband mixing in the frequency multiplier is observed and explained.