Digital Phase Splitter 4F correction as per Hurz observations

165

01:18:46

Purpose: provide phased outputs for use by a quadrature sampling detector (QSD), such as the Tayloe Detector

Pro: Ultra-broadband, excellent phase and amplitude balance, no lag or phase difference

Con: requires 4 X LO frequency

For a perfect quadrature phase shift, it is difficult to beat a digital phase splitter. The circuit is very simple – it takes 4 times the frequency required and does not use any NOR gate.

The result is two outputs that are in quadrature with each other. It is implemented with two D flip-flops with the inverted signal connected to the input.

This is then fed into a representation of MUX logic that would allow a signal to be sampled at 4 times per cycle of the incoming signal. This is typically done with capacitors, which hold the charge voltage long enough to be sent to an op-amp.

published 6 years ago

hurz

6 years ago

4*7MHz = 28MHz isnt 7MHz what you are interessted in? An analoge AC source with +-7V as digital clock signal? No, please use a logic train or a rectangular source. http://everycircuit.com/circuit/5309561182093312

hurz

6 years ago

here an old version fully gated, FFs were not available, anyway the analoge part is also more for simulation and needs irl good inverter driver. Zorg check this: http://everycircuit.com/circuit/4716393510207488 Your version is prefered, cuz this gate chaos i had here, nobody will put on a breadboard 😜

zorgrian

6 years ago

Thanks Hurz, I hadn't noticed the sign wave signal was still in circuit

hurz

6 years ago

What is your experience with such kind of mixed signal? My are not as good, digital as close to analoge receiver are almost impossible, shielding is extreme difficult and only working if you put things into metal boxes and close them, soldered so you can never open them again ;-) noisy digital divider are problematic. One importante thing i learned over decades, dont used the best and fastest digital technology available, cuz they generate more harmonics as you wish to have. Use just whats needed. E.g. for 7MHz slow 74LS74 suppose todo and no 74F74 or so is needed. For selfmade PLLs its a nightmare but a must to get under control. Do you have a practical working example of such a quadratur divider and analoge receiver part on one PCB?

zorgrian

6 years ago

Yes I have experience. My friend Hans summers has a product that is QSD. It's very affordable and we have designed and produced a 50 watt amplifier that uses pin diode switching