How to produce short pulses (comb generator) ?

[Eugen_E]

comb generator

Hello,

I need to make a comb generator (discrete) to produce marker frequencies with 10MHz spacing, with almost constant level to at least 1GHz.
I will use a 10MHz crystall oscillator and a pulse generator, with t<1 ns.

What circuits can be used for this - that don't include step recovery diodes and exotic parts.

A nonlinear amplifier/multiplier using transistors with transition frequency > 6 GHz would be better?

Thanks

 

[Siniša]

short pulses

You could build **broken link removed**, or use integrated. Plenty of choices.

 

[Eugen_E]

comb generator >1 ghz circuit

Thanks for the reply.

I need this for a comb generator, to generate marker frequencies, not for testing diodes. So the pulse amplitude doesn't have to be high, but the pulse width should be < 1ns, thus the rise/fall times should be, the lowest possible.
So I need something that feed with 10MHz will generate quite constant armonics (the levels for odd or even should be near) to at least 1GHz.

I mean something like in this style, maybe with a few design considerations/equations:
http://www.vk2zay.net/article.php/41

 

[Eugen_E]

schottky diode + comb generator

Found another one:
http://lea.hamradio.si/~s57uuu/astro/sidi_debug/harmgen_w_rtx.htm
http://lea.hamradio.si/~s53mv/spectana/sa.html

But it requires tuning and verification to get near amplitude harmonics.

 

[rfmw]

The simple harmonic generators will never give you equal spectral lines if you ask me. The variation in the amplitudes is more than 10dBs. What would help you is a high-speed PRBS generator with at least 2.5Gbps bit rate, 5Gbps recommended. The PRBS spectrum consists of discrete lines with more or less sin(x)/x envelope. You must calculate the PRBS polynomial order and clock frequency for the exact 10MHz spacing. It is no easy task to build a PRBS generator yourself, look at existing solutions.

 

[Eugen_E]

Thanks. I won't go so complex, because is not a professional application... wanted to know the best option with common parts.
The BAT41 Schottky diode can be used at frequencies in the range of hundreds MHz?