This 1970 Electronic Design circuit uses a varactor or varicap. The circuit divides the frequency of a 150 MHz signal by 2. Similar versions appear on this site.
We found the configuration below, with unit gain, in the National Semiconductor Linear...
This circuit is from an Electronic Design from the 90's. The main integrated circuit is uncommon...
This circuit appears on this site from different sources. This is from documentation from the...