Wideband phasemeter

A zero-crossing phasemeter using a new phase detector is described. Because high-speed logic and ultrafast current switches are used, coupled with a new current-subtraction technique which tends to cancel out switch errors, the phasemeter is capable of functioning satisfactorily at frequencies up to 50 MHz. The phase detector, when used in conjunction with a judiciously selected control signal, has noise-rejection properties superior to conventional circuits