Range measurement by means of frequency modulated continuous wave radar

摘要: A continuous wave FM range measuring apparatus for transmitting a signal F which is linearly modulated by sawtooth over frequency excursion ΔF during duration T and has central f1. phase loop provided stabilizing f1 with the precision of quartz oscillator. mixer produces beat fb between transmitted received F' reflected from an object. The φbo Fb at beginning ramp are measured. distance calculated, preferably means microprocessor (10), first calculating approximate value d1 d to be determined radar object as function ΔF, T. Then more precise second d2 calculated d1, fo ramp. In preferred embodiment, level liquid in container