| 摘要 |
<p>PURPOSE:To enable adaption to an optional sent/received waveform including the conversion error of an A/D converter by obtaining a filter coefficient by using the A/D converter and an FFT circuit which form part of the digital pulse compressing device. CONSTITUTION:A digital switch 9 is switched at the time of initialization so that an output is obtained at a complex conjugation circuit 10; and a sent signal is converted into a digital signal through a phase synchronizing detector 1 and the A/D converter 2. Further, the FFT circuit 3 performs Fourier transformation to obtain a frequency spectrum X)omega), which is led to the circuit 10 and converted into a complex conjugate value X*(omega) and then written on a filter coefficient memory 5. Then an analog switch 8 is switched in pulse compressing operation so that an IF received signal input is passed and a sent signal is cut off. The switch 9 is so switched that the output is obtained at a complex multiplier 4; and an IF signal input makes the switch 9 to output the spectrum X(omega) to the multiplier 4. The conjugate value X*(omega) is read out of the memory 5 and multiplied by X(omega) and the result is processed by reverse Fourier transform processing to obtain a pulse compression output in time series.</p> |
