| 摘要 |
PROBLEM TO BE SOLVED: To provide the spread spectrum demodulation circuit that suppresses a temperature change in a delay in a surface acoustic wave delay line so as to provide an output of a proper integration waveform. SOLUTION: The spread spectrum demodulation circuit has a surface acoustic wave matched filter 1, a surface acoustic wave delay line 4, a 1st matching circuit 3 causing a delay to a 1st correlation signal, a 2nd matching circuit 6 causing a delay to a 2nd correlation signal, and an integration circuit 7 that integrates the 1st correlation signal outputted from the 1st matching circuit and the 2nd correlation signal outputted from the 2nd matching circuit so as to demodulate a spread spectrum signal (s), and a temperature change in a difference between a delay in the 1st matching circuit 3 and a delay in the 2nd matching circuit 6 is a change to cancel the temperature change in the delay of the surface acoustic wave delay line 4 by the temperature coefficient of a piezoelectric substrate 16 used for the surface acoustic wave line 4. |
