Would like to understand how to physically realize
for example Phase detector for 100Khz signal and
Vector modularot for same frequency.
for clarification
when I see, for example,
She can not under the present no specific hardware
where I can find sample solutions and a description of how such things
I don't know of any off the shelf solutions for 100kHZ. But there are many for higher frequencies. For example, see LTC5599 and LTC5584 from linear tech.
For 100kHz you would have to make your own phase shifters and multipliers. Or do it digitally with ADCs and DACs.
The schematic snippet looks like being copied from an Agilent auto-balancing LCR meter, e.g. 4284A. Possible implementation depends on the kind of reference signal and accuracy requirements. In case of 4284A, four-quadrant analog multipliers are used, as far as I know.