PARAMETRIC AMPLIFIER.

The use of computer techniques allows for the saving of valuable time in accurately designing a lumped circuit parametric amplifier. To show the development of such a computer program, the general theory of parametric amplifiers will be discussed with some equation development. The necessary conditions for parametric amplification is then outlined as the amplification criterion and a circuit containing basically four tuned tanks, a varactor, and load resistor, operating at one megacycle is shown to meet the parametric amplification criterion. From the knowledge of the necessary conditions for parametric amplification and the circuit equations developed, a complete computer program is developed to verify that a circuit and varactor will operate as an amplifier. The only information that needs to be included in the FORTRAN program is the desired operating signal and pump frequencies, the value of one component of the tank circuits and the characteristics of the varactor. If the conditions for parametric operation are satisfied, the computer will then determine the remaining circuit components, retaining only those which are realizable. The program also selects the best operating conditions from the many hundreds available. For each point selected, the computer will determine, among other things, the negative resistance and the component values of the impedance matching networks. Author