摘要 |
<p><P>PROBLEM TO BE SOLVED: To eliminate a DC offset by performing frequency conversion of self-mixing when converting a multiband OFDM_UWB (orthogonal frequency division multiplexing_ultra wideband) signal by a direct conversion method. <P>SOLUTION: Capacitors #1, #2 and #3 are prepared for each of frequency bands #1, #2 and #3 to be hopped. The capacitors are switched in synchronization with frequency hopping, for example, the capacitor #1 holds electric charge just before frequency hopping from the frequency band #1 to another frequency band #2, and when hopping is performed to the frequency band #1 again, the capacitor #1 continues step response. Thus, the discharge and charge of the capacitor #1 are eliminated to makes the capacitor #1 settle in a steady state soon. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |