| 摘要 |
PROBLEM TO BE SOLVED: To provide a sampling device capable of converting modulated signals to a low frequency without using the mixer circuit of high accuracy or the filter of steep characteristics. SOLUTION: After sampling the modulated signals received by an antenna 101 and inputted through a low noise amplifier 102 and a band-pass filter 103 by a sampling frequency higher than the signal band of the modulated signals by a first sample-and-hold circuit 104, they are inputted to an analog decimation filter 105 and frequency components to be foldover noise are eliminated. The output of the analog decimation filter 105 is sampled by the sampling frequency lower than the sampling frequency of the first sample-and-hold circuit 104 by a second sample-and-hold circuit 106, digitized in an A/D converter 107 and then, demodulated in a demodulator 108. |
