A stabilized X-band oscillator with frequency control

Abstract

This laboratory work was conducted to design a system for stabilizing and controlling the frequency of a 2K25 klystron. A functional schematic diagram of the system is presented in Figure 1. If the electrical lengths shown by the dotted and full lines of Figure 1 are made equal, the system will be broad-band in frequency. This broadband feature was considered to be the primary feature recommending the system. Stabilization and control of the oscillator over a 30 mcps range with fixed mechanical tuning was achieved. However, the broad-band nature of the stabilized system was not realized in operation. The amplifier output modulates the oscillator signal at Crystal A in Figure 1. the upper-sideband is passed through the cavity and mixed with the oscillator signal at Crystal B for detection. The lower-sideband must be suppressed to prevent its travelling through the waveguide path which does not include the cavity, to Crystal B for detection. Two waveguide assemblies were devised to accomplish this suppression. Neither one was too successful in this respect. Developments of the resultant system of this laboratory work that may be profitable are: a) using a reflection type cavity and both side-bands as in the Found-Saffarano method of stabilization, b) use the conversion of cavity phase-shift to amplifier frequency-shift in measurements, c) improve the waveguide assemblies of this thesis to suppress the unwanted sideband, d) employ this stabilization method in an F.M. system.