Friday, July 8, 2016

The struggle to make the ADF4351 10MHz reference signal.

The ADF4351 PLL needs a  full TTL level  at 50OHm in the 10MHz reference.

The internal TCXO delivers 5V pk  at the ADF reference port.
Then the resulting signal at 1296 / 1152 MHz is a clean small carrier
about 60dB S/N  at the SDR RTL stick
Using  400mV tt  clean sinus signal from the amplified GPSDO ( 40mV pk)
gave a broad raspy tone at the output port of the ADF
I tried a MMIC demo ampl. with the MAR6  and INA10386
DC to 2GHz broadband amps  
got a clean 40mV pk 10MHz  at the input of the INA
 measuring 5V DC supply ,  2V bias at the output pin and  0.2V bias at the input pin
of the INA10386,  normal levels.
40mV tt at the input resulting in 0V out..
coupling C 10nF  L 10uH
Why this MMIC do not work for 10MHz ?
i do not know yet
maybe  my  10MHz  driving issue can be solved by a simple opamp
or an other discrete part amplifier like the one below
optimised in Multisim
I  have to be sure of the solution before I start to trial and error soldering again
It can not be that difficult to make a 3Vtt 10MHz clock  signal???



INA 10386  Agilent /HP  DC-1.8GHz  claimed 26dB gain
I had  0 output with 40mVtt 10MHz in  but after lowering the original 56Ω to 18Ω
the device I 5mA  up to 38mA then the device starts to amplify 

No comments:

Translate