| 摘要 |
A data transmission device for sending back data on a reflected wave of an unmodulated carrier, the data transmission device includes: an antenna adapted to receive an unmodulated carrier Fo from a data reader with which data is to be exchanged and send a reflected wave of the unmodulated carrier Fo to the data reader; subcarrier oscillation means for generating a subcarrier frequency Fs; subcarrier modulation means for digitally modulating sending data on the subcarrier Fs; D/A conversion means for generating the analog modulated subcarrier wave Fs by converting a digital modulated signal, generated by the subcarrier modulation means, into analog form; and frequency mixing means for mixing the unmodulated carrier Fo and modulated subcarrier wave Fs to generate new modulated waves Fo+Fs and Fo−Fs.
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