DELAY PHASE LOCKED LOOP CIRCUIT FOR SPREAD SPECTRUM COMMUNICATION DEVICE

摘要

PROBLEM TO BE SOLVED: To establish synchronization by always optimizing a cut-off frequency of filters in response to a spread bandwidth that is optionally set. SOLUTION: A frequency-voltage converter 11 detects a frequency of a reference clock signal outputted from a voltage controlled oscillator 9 as a frequency of a reference pseudo noise code and adjusts a cut-off frequency of low pass filters 4, 5. Thus, synchronization is established by always optimizing the cut-off frequency of the filters 4, 5 in response to the spread bandwidth.