Low flicker phase noise diodes and amplifier

Hello!
This is my very first post, but I was lurking for a lot of time!
I need your advice on a 10Mhz to 20 MHz doubler & amplifier.
I have a 10 MHz OCXO 7dBm with a very low phase noise (-160 dBc @ 1kHz) and I have to feed its signal to a PLL, that requires above 150 V/us slew rate.
I have two problems:
1) what schottly diode to use. I know that Avago has very low flicker diodes, but unfortunately Avago has been bought and some wise businessman shutted down everything.
2) what NPN BJT to use to achieve an additive phase noise of -165...-170 dBc/Hz at 1 kHz (20 MHz carrier).

You can find attached the circuit. I used a simple frequency doubler using Infineon BAT15 diodes, are they good? Actually, the doubler might be replacd with AMK-2-13, which has better harmonic rejection. I used a MMBT2222A NPN for the amplification, is it good? I attached also a simulation, Ic=38 mA. (*) If I parallelize two of them to lower rbb? Maybe a RF bjt is better?
I used another set of BAT15 to limit the output voltage swing. The output is differential, going to the PLL using 150ohm differential impedance tracks (distance is a few inches on the PCB...)

Do you have some advice to achieve low flicker noise? Thank you very much!

(*) one strange issue that I have is that sometime the amplifier don't work, it start to work if I tweak the supply voltage or change the capacitor values by a few pF. Maybe it has two stable operating points?

There are some rules to get low flicker noise. You have to use JFETs, or medium power BJTs with ft no higher than twice of the working frequency. JFETs have the lowest flicker noise of all transistors, followed by BJTs. The reason of using of medium power BJTs is because they have higher parasitic capacitances due to higher die footprint, and so, lower flicker noise.
When designing a transistor for low flicker noise, have to give attention to the bias noise impedance and bias filtering. For example in your example adding a small 5-10 ohms in series with L3 would help reducing the flicker noise of T2.
The process of frequency multiplication inevitably increases the flicker noise (or phase noise in general) by a rate of 20*LOG(N) where N is the frequency multiplication factor.

Hello!
Thanks fr the answer!

vfone said:

You have to use JFETs, or medium power BJTs with ft no higher than twice of the working frequency..

Click to expand...

But JFET have higher noise wrt BJT if the source impedance is low. My source impedance is 50 ohm. And I dont find an SMD JFET with low noise...

vfone said:

When designing a transistor for low flicker noise, have to give attention to the bias noise impedance and bias filtering. For example in your example adding a small 5-10 ohms in series with L3.

Click to expand...

Can you elaborate this? I though that adding a series resistor would add additional noise. I already put a 10 ohm emitter resistor to linearize a bit the BJT, why this 10 ohm in series?
Thanks