How can you connect a Colpitts oscillator to an low pass filter (which will have a variable capacitor), and the output of the low pass filter to a log RF detector (e.g. AD8307)?
(I want the variable capacitor in the low pass filter to alter the attenuation of the rf signal, and the resulting power to be detected by the AD8307)
The schematic is for the Colpitts oscillator. When I add an low pass filter to "Freq_out" the oscillations die out very rapidly, I assume that adding a low pass filter affects the feedback to the tank circuit of the oscillator.
(I want the variable capacitor in the low pass filter to alter the attenuation of the rf signal, and the resulting power to be detected by the AD8307)
The schematic is for the Colpitts oscillator. When I add an low pass filter to "Freq_out" the oscillations die out very rapidly, I assume that adding a low pass filter affects the feedback to the tank circuit of the oscillator.
Attachments
-
1.3 KB Views: 15