JPS5711520A - Elastic surface wave resonator - Google Patents

Abstract

PURPOSE:To obtain a resonator with good figure of merit, by specifying the pitch between electrodes and width of electrodes for an energizing electrode and a pair of relfection electrodes formed on a piezoelectric substrate for an RF converter of a VTR. CONSTITUTION:An one major plane of a piezoelectric substrate 11 of LiTaO3, an energizing electrode 12 forming comb type electrodes 12a1, 12b1 from a pair of common electrodes 12a, 12b so that they are meshed, and reflection electrodes 13, 14 provided between a pair of common electrodes 13a, 13b and 14a, 14b at both sides of the electrode 12 with a prescribed interval, are formed. A signal with a prescribed frequency is applied between terminals 121 and 122 of the electrode 12, and the surface wave of a substrate 11 is reflected by the electrodes 13, 14 for the direct oscillation of a prescribed frequency. With this constitution, taking pitch between the electrodes 12a1, 12b1 and between the electrodes 13 and 14 as P, the electrode width between the electrodes 12a1, 12b1 and the electrodes 13, 14 as WT, WG respectively, a resonator with good figure of merit can be obtained by specifying the P, WT, WG as equations listed.