Abstract: A high-frequency module includes a semiconductor chip device that is mounted on an external circuit substrate by wire bonding. A switch forming section, a power amplifier forming section and a low noise amplifier forming section, realized by a group of FETs, which are active elements, are formed in the semiconductor chip device. Flat plate electrodes, which form capacitors are formed in the semiconductor chip device. Conductor wires that connect the external circuit substrate and the semiconductor chip device function as inductors. A group of passive elements that includes inductors and capacitors is formed. As a result, a high-frequency module that can be reduced in size while still obtaining the required transmission characteristic is realized.

Abstract: The present invention provides a piezoelectric ceramic composition which predominantly comprises a composition represented by the following formula :(1-n)(K.sub.1-x-y Na.sub.x Li.sub.y).sub.m (Nb.sub.1-z Ta.sub.z)O.sub.3 -nM1M2O.sub.3wherein M1 represents a divalent metal element such as Mg, Ca, Sr or Ba; M2 represents a tetravalent metal element such as Ti, Zr, Sn or Hf; and x, y, z, m, and n satisfy the following conditions: 0.9.ltoreq.X; y.ltoreq.0.3; x+y<0.75; 0.ltoreq.z.ltoreq.0.3; 0.98.ltoreq.m.ltoreq.1.0; and 0<n<0.1.

Abstract: The present invention provides a method for producing a piezoelectric ceramic element in which evaporation of Pb contained in a piezoelectric material is prevented and which allows use of inexpensive metal as an electrode material without substantial deterioration of piezoelectric characteristics. The method includes the steps of (1) mixing at least oxides of Pb, Zr, Ti, Cr and Nb; (2) calcining the mixture; (3) crushing the calcined product and adding a Cu component in an amount of about 0.05-3.0 wt. % calculated as CuO; (4) adding a binder to the Cu-component-containing mixture; (5) molding the binder-containing mixture; (6) firing the molded product at 1100.degree. C. or less to produce a sintered product; and (7) forming electrodes on surfaces of the sintered product, the sintered product containing a primary component represented by the formula:Pb.sub.a [(Cr.sub.x Nb.sub.(1-x)).sub.y Zr.sub.(1-b-y) Ti.sub.b ]O.sub.3wherein 0.95.ltoreq.a.ltoreq.1.05; 0.40.ltoreq.b.ltoreq.0.55; 0.10.ltoreq.x.ltoreq.0.

Abstract: A piezoelectric speaker in which a diaphragm containing a piezoelectric driver is fixed on a frame through an elastic supporting member. The diaphragm is an assembly of two resin foam plates facing each other. Each resin foam plate has a recess and a projecting member at the substantial center of the recess bottom. The piezoelectric driver is accommodated in the space made of the two recesses while being interposed and supported by the projecting members at the substantial center thereof.