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. No buffer needed.
Con: requires 1f and 2f X LO frequency
Note: this is only good if the supplied signals are in phase, 50% duty and otherwise non fucked up
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.
