Piezoelectric vibrating element having a rectangular configuration

摘要

A vibrating element for the vibration under an expansion mode has a substrate made of a constant modulus alloy and has a rectangular configuration defined by opposite long sides and opposite short sides, a thin piezoelectric film deposited on the substrate, and a vibration electrode film deposited on the piezoelectric film. When an equivalent circuit of the vibrating element can be defined as including a resonance inductance L, a resistance R and a series capacitance Cs, which are connected in series and a parallel capacitance Cp, which is connected parallelly to the series connection of L, R and Cs, a ratio of short side to long side of the substrate is selected to have values around points where a ratio of parallel capacitance Cp to serial capacitance Cs shows negative peaks.