afz23
Full Member level 3
Hi,
I am looking for a Buffer amplifier circuit at 4GHz,I need
a very good isolation(better than 50dB) between locked
VCO output(4GHz) and next stage (an analog phase modulator).
Experimentally I have observed that 20dB isolator is not
enough to isolate these two stages.I get over modulation
( 3 times of the expected modulation) when I connect these
two stages via a 20dB isolator.
As per datasheet VCO(Teledyne-Cougar) OC4500,frequency
pulling for this VCO is 55MHz at (VSWR 1.67:1 or RL 12dB).
---------- Post added at 06:29 ---------- Previous post was at 06:27 ----------
I think a C-Band BJT can do this job.May be a AT42070.
Kindly suggest circuit for this.
I am looking for a Buffer amplifier circuit at 4GHz,I need
a very good isolation(better than 50dB) between locked
VCO output(4GHz) and next stage (an analog phase modulator).
Experimentally I have observed that 20dB isolator is not
enough to isolate these two stages.I get over modulation
( 3 times of the expected modulation) when I connect these
two stages via a 20dB isolator.
As per datasheet VCO(Teledyne-Cougar) OC4500,frequency
pulling for this VCO is 55MHz at (VSWR 1.67:1 or RL 12dB).
---------- Post added at 06:29 ---------- Previous post was at 06:27 ----------
I think a C-Band BJT can do this job.May be a AT42070.
Kindly suggest circuit for this.