Abstract: An electronic component includes: a package that includes a metal portion formed by pressing a metal, and an insulating portion attached to the metal portion through fusing; a chip housed in the package; first external terminals that are electrically connected to the chip with metal wires, and are partially embedded in the insulating portion; and ground terminals that are convexities of metal portion and are electrically connected to the chip with metal wires, connecting points between the first external terminals and the chip being located at the same height as connecting points between the ground terminals and the chip.

Abstract: Transducers are connected in parallel on a piezoelectric substrate. Each of the transducers is constituted of RSPUDTs. The RSPUDTs include SPUDTs that are opposed to each other such that their propagation directions are opposite to each other. The SPUDTs have a unidirectional electrode structure having a propagation characteristic.

Abstract: An electronic component includes: a package that includes a metal portion formed by pressing a metal, and an insulating portion attached to the metal portion through fusing; a chip housed in the package; first external terminals that are electrically connected to the chip with metal wires, and are partially embedded in the insulating portion; and ground terminals that are convexities of metal portion and are electrically connected to the chip with metal wires, connecting points between the first external terminals and the chip being located at the same height as connecting points between the ground terminals and the chip.

Abstract: A band filter is provided which can freely set the bandwidth and blocking characteristic without any need for a high level designing and adjustment. To this end, a surface acoustic wave device is so constructed as to connect a main filter Fm and sub-filter Fs in a parallel array. Here, relative to a frequency area corresponding to a passband of the main filter Fm the frequency-attenuation amount characteristic of the sub-filter Fs has a blocking band and, relative to a slope portion formed outside a passband of the main filter Fm, the frequency-attenuation characteristic of the sub-filter Fs has a rising area constituting a passband and signals involved provide an opposite-phase relation.

Abstract: Transducers are connected in parallel on a piezoelectric substrate. Each of the transducers is constituted of RSPUDTS. The RSPUDTs include SPUDTs that are opposed to each other such that their propagation directions are opposite to each other. The SPUDTs have a unidirectional electrode structure having a propagation characteristic.

Abstract: A resonant surface acoustic wave filter device comprises an inter-digital transducer that has a first electrode area that excites a surface acoustic wave and a second electrode area that excites a surface acoustic wave of inverted phase with respect to that excited in the first electrode area, and grating reflectors. By selecting appropriately a ratio of numbers of electrode pairs and a pitch of electrodes of the first area and the second area, band pass characteristics and impedance characteristics of the filter devices can be controlled.

Abstract: In the manufacturing process of the exhaust gas purifying catalyst (3), rhodium is supported by the base material using the rhodium carbonyl cluster solution in which rhodium carbonyl cluster is dissolved into methanol in the step of forming the upper catalytic layer (6) including rhodium and platinum as catalytic metals. By this, the dispersibility of rhodium in the base material is highly raised, and further rhodium is effectively restrained from being oxidized during the manufacturing process of the catalyst (3). Thus, according to the exhaust gas purifying catalyst (3) particularly, the purifying performance of NOx at both of lower exhaust gas temperature and higher exhaust gas temperature is highly improved.

Abstract: The active temperature of an exhaust gas cleaning catalyst is shifted to a higher temperature side when Al.sub.2 O.sub.3 and/or CeO.sub.2 is used as a co-catalyst and/or when an oxidation number of Pt or Ir which is used as the noble active component is plus four.

Abstract: In the exhaust gas purifying catalyst (3), palladium is contained as a catalytic component and cerium oxide and (Ce, Pr) compound oxide is contained as a promoter. Now, the weight ratio of cerium oxide to (Ce, Pr) compound oxide is set between 9/1 and 7/3, and the ratio of praseodymium to cerium in the (Ce, Pr) compound oxide is set between 3 mol % and 50 mol %. In this way, because in this exhaust gas purifying catalyst (3), palladium with high low-temperature activity is used for a catalytic component, the exhaust gas purifying performance at low temperature is improved. And because cerium oxide and (Ce, Pr) compound oxide improves catalytic activity of palladium at high temperature, the exhaust gas purifying performance at high temperature, in particular, NOx purifying performance, is improved.

Abstract: An exhaust gas purifying catalyst is produced by, after contacting a ceria powder with a palladium solution and burning the ceria powder to support the palladium on the ceria powder, forming a coating layer of the ceria powder on a catalyst support and impregnating the coating layer with a solution of cerium and burning it to provide palladium oxide particles fixed around ceria particles and a ceria coating so as to cover the palladium particles.

Abstract: In an exhaust gas disposable catalyst which is a .gamma.-alumina catalyst prepared by sol-gel process, .gamma.-alumina has more than 300 m.sup.2 /g specific surface area and the catalyst element is supported on the .gamma.-alumina and dispersed in pores thereof. The exhaust gas disposable catalyst is obtained by adding the catalyst element as a solution of salt before gelating in sol-gel process.