Provided is an apparatus and a method of measuring a distance between
devices using a low clock frequency signal. The apparatus includes clock
frequency generators, counters, a controller and a calculator for
determining the distance based on clock signal overlap. Radio waves are
transmitted and a number of clocks of a clock signal having a clock
frequency b are counted, and if the transmitted radio waves are received
again, a number of clocks of a clock signal having a clock frequency a
are counted. If the clock signals having the clock frequencies a and b
overlap with each other, counting of the numbers of the clocks of the
clock signals having the frequencies b and a stops, and the distance is
measured using the count values of the clock signals having the clock
frequencies a and b. As a result, number of clocks of clock signals
having low clock frequencies with a uniform difference can be counted to
precisely measure a distance.