A passive phase jitter modulation (PJM) tag is charged with power in a continuous wave (CW) section. When receiving a command from a reader, the passive PJM tag must recognize the command and determine exactly when to begin demodulating the command. Only then can the passive PJM tag demodulate the command. To this end, a synchronization apparatus for accurately demodulating a signal input to a PJM tag includes a plurality of correlators correlating a received phase jitter-modulated signal with a template of an internal matched filter which is in the same form as at least a portion of a modified frequency modulation (MFM) flag.
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