Abstract: In a piezoelectric filter, two vibrating element parts are arranged on longitudinal side portions of a rectangular flat plate shaped piezoelectric substrate, and a capacitor is arranged therebetween. Each of the vibrating element parts comprises a pair of vibrating electrodes which are arranged on an upper surface of the piezoelectric substrate at a distance, and an opposite electrode which is arranged on a back surface of the piezoelectric substrate to be opposed to the vibrating electrodes. The pair of vibrating electrodes of each Vibrating element part is arranged along an electrode arrangement direction which is inclined with respect to side surfaces of the rectangular piezoelectric substrate. The electrode arrangement direction for the vibrating electrodes is inclined with respect to the side surfaces of the piezoelectric substrate at an angle .theta. of inclination which is preferably in excess of 0.degree. and not more than 45.degree..

Abstract: An input leading electrode, an output leading electrode and a common leading electrode are provided on a first side of an element which has a specified electrical function. The element is held between an input terminal and an output terminal which face to the first side of the element and a common terminal which faces to a second side of the element. The output terminal and the input terminal are connected with the leading electrodes by ordinary soldering, and the common terminal and the common leading electrode are bridged with solder.

Abstract: A piezoelectric filter in which an earth electrode is provided in the center of a piezoelectric substrate in the direction of thickness; an input electrode is provided on the upper surface of the piezoelectric substrate so as to be opposed to one part of the earth electrode; an output substrate is provided on the lower surface of the piezoelectric substrate so as to be opposed to another part of the earth electrode except the aforementioned one part; a first dummy electrode is formed on the upper surface of the piezoelectric substrate so as to be opposed to the output electrode through the piezoelectric substrate; and a second dummy electrode is formed on the lower surface of the piezoelectric substrate so as to be opposed to the input electrode through the piezoelectric substrate.

Abstract: A piezoelectric filter of an energy-trapped type utilizing a second harmonic wave of the thickness-extensional vibration mode, characterized in that an earth electrode is formed around the center of a piezoelectric substrate in the direction of thickness, and an input electrode and an output electrode are formed on one or both major surfaces of the piezoelectric substrate so as to be opposed to the earth electrode.

Abstract: A piezoelectric filter of an energy-trapped type utilizing a second harmonic wave of the thickness-extensional vibration mode, characterized in that an earth electrode is formed around the center of a piezoelectric substrate in the direction of thickness, and an input electrode and an output electrode are formed on one or both major surfaces of the piezoelectric substrate so as to be opposed to the earth electrode.

Abstract: A piezoelectric resonator of an energy-trapped type utilizing a second harmonic wave of the thickness-extensional vibration mode, in which an inner electrode is formed in a position at a height around the center of a piezoelectric substrate in the direction of thickness, outer electrodes are formed on both major surfaces of the piezoelectric substrate so as to be opposed to the inner electrode through a piezoelectric substrate portion, and the dimension of at least one of the outer electrodes in the direction of the length of the inner electrode is made smaller than the dimension of the outer electrode in the direction of the width of the inner electrode.