control voltage 0 to 8 V driver supply voltage 3.3 to 5 V 3.3 to 5 V control pulse rising edge (there is a 49.9 Ω term. resistor hidden under here!) 100 fF cap here (on a little island isolated from ground) ignore, old stuff

best use SMA could be bigger could be smaller low leakage is best 3.3 to 5 V do not exceed 10 V !! in out For simplicity, I did not use C 2 and had C 1 +C 1 = 0.1pF (i.e. if I had used two caps in series they would be 0.2pF). But, I suggest do use the T circuit, use C 1 =0.5pF and figure C 2 for the amplitude you like at a good convenient voltage I suggest V C =3.0V is nice for the nominal amplitude out. BSS83 tie substrate to ground! some bypass caps

Detailed parts choices depends on your prototyping skills, experience, and available tools, and of course on availability. The circuit shown in the picture was not originally intended to be as fast as possible. The parts and construction techniques are sub-optimal. Use the smallest parts you can handle, on the signal path. Optimal performance will come from 0402 resistors and capacitors and very short connections. Of course, small ceramic chip resistors and capacitors are small, and fragile, so it may be a pain to prototype with. I suggest AVX thin film capacitors for <10pF values (you can buy from Digi-Key), any C0G capacitor for other signal path elements (such as C 2 on previous page). Better performance will come from an SMA connector on the output, depending of course on how you connect to it and what you plug in there...

For the “real” printed circuit board version of this thing, I will include double-pulse capability (maybe triple?) by replicating the pulser transistor and capacitors, and probably modifying the driver circuitry. Gary – please comment on what range of double-pulse separation is most interesting to test with. Should it go down to zero, or is it ok if there is a minimum ~5ns pulse separation? The issue is, do we have one control input (pulse it twice), or two? Reminder for the record of the output you should see from prototype described above