PURPOSE: To improve the efficiency of pump electric power by connecting voltage varactor diodes to pump electrodes on a propagation path for a surface elastic wave and by applying a pump voltage to them.
CONSTITUTION: A pump voltage of a frequency twice selected frequency f0 is applied from high-frequency power source 9 to voltage varactor diodes C1∼Cn. An electric signal applied to transducer 5 propagates on the surface of piezoelectric substance substrate A and while it is propagating through pump electrode groups M1∼Mn, a signal component of approximate frequency f0is parametric-amplified. The amplified signal is reconverted by transducer 6 into an electric signal, which is outputted. Since the sum of widths and intervals of pump electrodes M1∼Mn is made less of length λ0 of irradiation, mechanical reflection is reduced.
OKAMOTO TAKESHI
SAKAI TAKAMASA
