| 摘要 |
PROBLEM TO BE SOLVED: To demodulate the spread spectrum signal of high efficiency without requiring a generation circuit, or the like of a replica signal by inputting two high frequency signals to two surface acoustic wave(SAW) delay element, mixing respective output signal by a mixer and taking out the output signal of the frequency of difference. SOLUTION: Concerning a first delay element, a transducer 15 for SAW excitation and transducers 16-1 to 16-N for reception are formed at a piezoelectric substrate 1. Concerning a second delay element, a transducer 18 for SAW excitation and transducers 19-1 to 19-N for reception are formed at a piezoelectric substrate 1. The spread spectrum signal of a frequency fRF is inputted from a first input terminals 14. The nonmodulation continuous waves of a frequency fLO is inputted from a second input terminals 17. Each output signal from each delay element is mixed by mixers 20-1 to 20-N to obtain the output signals O(1) to O(N) of the frequency |fRF-fLO|of difference. |
