1. Home
  2. Electronics Design
  3. Help with understanding part of an RF oscillator.

Help with understanding part of an RF oscillator.

Simple circuit.....

1G RF NPN (gain 40 - 60).. base bias to +9 via 33K, 10K base to Gnd. Collector to +9 via inductor.O/P from collector via a cap. Base has a varicap +trim cap in series, and an inductor in parallel with that, fed to the base via 10pf Emitter has 150R with 15pf bypass cap. B-E cap of 10 pf. The circuit tunes from 300- 400 MHz. The question is, what is the funtion/effect of the BE cap, in relation to the lower end of the range?
Reply to
TTman
Loading thread data ...

Minimize varactor effect of internal Cbe?

Reply to
Glenn

Impedance adaption of emitter output to resonance circuit.

Reply to
Glenn

to

That's part of it; it also swamps the thermal variation of Cbe, IMHO.

Reply to
whit3rd

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.