Range finder which uses microwaves - for determination of distance to target using FM-CW radar principle, involves linear FM and IF phase measurement

摘要

The phase of the i.f. signals is changed in steps or monotonically, and the distance is derived from the i.f. phase measurement; a microwave phase shifter is provided in the senser; transmission device. Alternatively a distance dependent shift of the transmitted signal initial frequency is used for phase shifting; or a frequency shift of the transmitted signal may be used for phase shifting; or a phase shifter may be provided in the i.f. range; or a frequency shift in the i.f. range may be produced by a single sideband receiver mixer.