multiplier & filter/Match

[VT1]

Hello all, I am new to RF design and I am in need of some help. VSWR helped me do an amplifier design in Genesys but what I what to do now is make a multiplier. The overview is:

Osc running at 25mhz > buffered > Filter/match to 50mhz harmonic > Buffer x2.

I managed to do the amplifier opt/simulation with the help of VSWR, but I am unclear how to attach the oscillator to the first buffer and how to do the simulation and optimization for the doubler and the filter/match network to make my multiplier.
Any help would be much appreciated.

 

[activewei]

what do u use to design the amplifier.

Give more detail of the design so that other can comment or suggest...

 

[VSWR]

Here's a simple frequency doubler using, silicon or Schottky diodes. Insertion loss is about 9 dB at 40/80 MHz, probably a little less at your frequency.

**broken link removed**

Or you can use the LM1496 IC. See page 8 and 9 of this application note:

www.onsemi.com/pub/Collateral/AN531-D.PDF

 

[VT1]

Hi all, this what I have done so far. Please if you see any problems then tell me as I am new and trying to learn RF design or the basic’s any way. The circuit has been optimized for maximum gain. The resonate circuit between the first amp and the second amp picks off the first harmonic. This circuit works on the bench but the resonate circuit is very sensitive. From this point I have come to a standstill and need help on these few questions.

1. Is this the best way of making a doubling circuit. Are the diodes better, cheaper, less component count, less noise?
2. What other parameters do I need to consider when optimizing the circuit. I believe the K factor has to be over 1?
3. How can I simulate the Resonate circuit and see how responsive it is in this circuit. Do I use a harmonic balance simulator?
4. Very Important: How do I add a 2n4427 transistor to this simulation as there are no spice files on the net and I do not understand which parameters I have to manually enter into genesis.


Many Thanks
VT1