| 摘要 |
A radio tag reader comprises low-pass filters (31, 33) for passing a frequency component (40 kHz) corresponding to a communication speed (40 kbps) of the tag reader among baseband signals I, Q converted by a frequency conversion unit (10), and demodulates the signals I, Q which have passed through the filters (31, 33). The tag reader further comprises band-elimination filters (32, 34) for eliminating the frequency component (40 kHz) corresponding to the communication speed (40 kbps) of the tag reader among the signals I, Q which have passed though the filters (32, 34), and executes carrier sense to the signals I, Q which have passed through the filters (32, 34). |
