Jean-Louis Naudin - 25 April 97 - Thanks to Fred B. Epps
In this version the pump signal is injected on the bias point of the varactors (in the middle), you can notice the 90 degres phase shift between the signal pump and the output signal. In the right scope picture the output current is measured through the 100 ohms resistor (R2).
Channel B : ( 200 mv/div => 2 mA/div )