| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To return a reflected wave while shifting a received frequency f<SB>0</SB>by a predetermined central frequency f<SB>s</SB>in either of positive and negative directions on a tag side. <P>SOLUTION: I and Q of a baseband input to a back scatter orthogonal modulator comprising an antenna and a high frequency switch are multiplied, respectively, by digitally modulated transmission data I having a central frequency f<SB>s</SB>and transmission data Q having a phase difference of 90°from the transmission data I to provide a signal. The modulation wave of a reflected wave digitally modulated to either of +f<SB>s</SB>or -f<SB>s</SB>from the frequency f<SB>o</SB>of an unmodulated carrier inputted from the antenna to the orthogonal modulator is then created and delivered from the antenna. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
