Linear Frequency Modulation of Oscillators
HARRY DIAMOND LABS ADELPHI MD
Pagination or Media Count:
A technique is described for using varactors to obtain wideband frequency modulation of an oscillator. The modulation characteristics are linear with modulating voltage to within a fraction of a percent over bandwidths of up to 10 percent. Attainable linearity is a function of the bandwidth sought. The technique employed depends on the proper proportioning of a two-pole RF network in which the varactors are a component. It is shown that the higher frequency impedance pole moves linearly with varactor tuning voltage over the desired bandwidths. The technique is theoretically adaptable to any varactor power law. Graphs have been computed for varactors having capacitance of the form C a the square root of V.
- Electrical and Electronic Equipment