| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the need of a replica generation circuit and to provide the output signal of a large level by independently inputting a spread spectrum signal and a non-modulation signal to a SAW(surface acoustic wave) delay element, taking products in an external mixer and weighting the output of the mixer in accordance with a code string. SOLUTION: Two transducers for SAW excitation 15 and 18 are formed on a piezoelectric substrate 1 and transducers 16-1, 16-2, 19-1 and 19-2 receiving excited SAW from them and inversely converting them into electric signals again are formed. For compensating phase fluctuation by a temperature, a second auxiliary delay element is prepared in addition to a first delay element. Phase delay from the reception transducers 19-1 and 19-2 when the continuous wave of a frequency (f) is inputted to the excitation transducer 18 of the second delay element is obtained. When the mixer is connected to both outputs and the difference (f3 =f1 -f2 ) of both frequencies is outputted, the temperature is compensated by the second auxiliary delay element. |
