Graded junction varactor frequency divider circuits employing large division factors

Claim 1

A frequency divider circuit for dividing an input signal of a given frequency by a large factor comprising: a. a varactor diode having a first and second terminal and a graded junction therebetween, characterized by a first region of a heavily doped semiconductor material of a given conductivity conductor contiguous with a second region of a lighter doped semiconductor material of opposite conductivity defining a central region contiguous at one end with a third region of a semiconductor material of same conductivity as said central region and an impurity doping level approaching that of said first region, said varactor diode exhibiting a capacitance variation inversely proportional to an integral root of a voltage applied across said first and second terminals, b. means coupled across said first and second terminals, including a tuned circuit for applying a relatively high frequency signal thereto, and c. means coupled to said varactor and resonant at a lower frequency to provide across said means a frequency related to said high frequency but different therefrom by said large factor, said large factor being in excess of 100, whereby said lower frequency is relatively equal to said high frequency divided by said large factor, said high frequency signal acting as a pump source for said varactor to enable divisions by said large factors in a parametric mode.