Abstract: Disclosed is a polyester produced from an aluminum compound and a phosphorus compound in the presence of a polycondensation catalyst. The polyester contains a polyester-insoluble, aluminum-containing insoluble particle in an amount of 1000 ppm or less as quantified by the method disclosed in the description, and contains an acid terminal group at a ratio of 10 to 50 eq/ton. The polyester can provide a highly transparent molded article produced through drawing (e.g., a film or hollow molded article) and is useful in the fields of highly transparent optical films, ultra-highly transparent molded articles or the like.

Abstract: The invention provides a polyester produced in the presence of a polycondensation catalyst comprising at least one compound selected from a group consisting of aluminum compounds and at least one compound selected from a group consisting of phosphorus compounds and being excellent in color tone, thermal stability, and transparency and improved in terms of insoluble particles. Particularly, the invention provides a polyester in which the content of an aluminum containing insoluble particles in the polyester is 3500 ppm or lower and a polyester which has a haze value of 2% or lower when being formed into a monoaxially oriented film. The aluminum catalyst for attaining these characteristics and properties may be polyester polymerization catalyst obtained by mixing an aluminum compound and a phosphorus compound in a solvent and has specified spectral characteristics in the side measurement of 31P-NMR spectrum and 27Al-NMR spectrum.

Abstract: A polymerization catalyst for polyester production which contains neither a germanium compound nor an antimony compound as a major component. It contains aluminum as the main metallic ingredient, has excellent catalytic activity, and gives a polyester which is effectively inhibited from suffering thermal degradation, during melt molding, without deactivating or removing the catalyst, and is excellent in thermal stability, stability to thermal oxidation, and hydrolytic resistance. The polymerization catalyst contains as a first metallic ingredient at least one member selected among aluminum and compounds thereof and further contains a phosphorus compound represented by a specific chemical formula. The polyester produced with this catalyst is usable as fibers, films, sheets, various moldings including hollow moldings, etc.

Abstract: A polymerization catalyst for polyester production which contains neither a germanium compound nor an antimony compound as a major component. It contains aluminum as the main metallic ingredient, has excellent catalytic activity, and gives a polyester which is effectively inhibited from suffering thermal degradation, during melt molding, without deactivating or removing the catalyst, and is excellent in thermal stability, stability to thermal oxidation, and hydrolytic resistance. The polymerization catalyst contains as a first metallic ingredient at least one member selected among aluminum and compounds thereof and further contains a phosphorus compound represented by a specific chemical formula. The polyester produced with this catalyst is usable as fibers, films, sheets, various moldings including hollow moldings, etc.

Abstract: A method of adjusting characteristics of a dielectric filter including the following steps: forming a dielectric filter having a dielectric body, the dielectric body having an outer surface; forming an external conductor on the outer surface of the dielectric body; and forming at least one hole extending through the dielectric body, the at least one hole having a respective inner surface, and a respective internal conductor and a respective non-conductive portion at the inner surface; the outer surface of the dielectric body comprising first and second end surfaces and a side surface extending between the first and second end surfaces; the at least one hole extending through the dielectric body between the first and second end surfaces; the respective inner conductor being formed as a respective pair of internal conductors conductively connected to the external conductor at respective ends of the at least one hole, the respective non-conductive portion at the inner surface of the at least one hole being space

Abstract: A compact LED module capable of preventing electrostatic destruction is provided. This LED module has first, second, and third terminals; first and second light emitting diodes connected between the first and second terminals and also connected in inverse parallel to each other; and a third light emitting diode connected between the first or second terminal and the third terminal. The first light emitting diode is a green light emitting diode, the second light emitting diode is a blue light emitting diode, and the third light emitting diode is a red light emitting diode.

Abstract: A small-sized low-loss dielectric resonator, dielectric filter, and dielectric duplexer, and a communication device using such an element. Through-holes are formed in a dielectric block. The inner surface of each through-hole is covered with a thin-film multilayer electrode consisting of an outermost conductive layer and a multilayer region including thin-film conductive layers and thin-film dielectric layers. An outer conductor having a similar thin-film multilayer electrode structure is formed on the outer surface of the dielectric block. An outer conductor in the form of a single-layer electrode is formed on a short-circuited end face of the dielectric block thereby connecting together the thin-film conductive layers of the inner and outer conductors.

Abstract: A dielectric filter or a dielectric duplexer is provided which comprises a dielectric block in a substantially rectangular parallelepiped shape, having a pair of opposite parallel end-faces and plural sides extending between the paired opposite end-faces, one of the plural sides being a mounting face; plural resonator holes elongating through the inside of the dielectric block across the paired opposite end-faces; inner conductors provided on the inner walls of the plural resonator holes, respectively; an outer conductor provided on the outside of the dielectric block; input-output electrodes provided only on one of the paired opposite end-faces, separated from the outer conductor, and capacitance-coupled to the predetermined inner conductors, respectively; and conductive terminals for external connection, connected to the input-output electrodes, having at least portions thereof lying substantially in the same plane as the mounting face.

Abstract: A dielectric filter having a dielectric body made of dielectric material and having an outer surface including first and second end faces; an external conductor disposed on the outer surface of the dielectric body; at least one hole extending through the dielectric body between the two end faces, the at least one hole having a respective inner surface; the at least one hole having a pair of internal conductors respectively provided in the corresponding hole and conductively connected to the external conductor at respective ends of the corresponding hole, a respective non-conductive portion at the inner surface of the corresponding hole being spaced from both ends of the respective hole and thereby separating the corresponding pair of internal conductors and defining a capacitance between the corresponding pair of internal conductors; the first end face of said dielectric body being closer to the non-conductive portion at the inner surface of the corresponding hole than the second end face; the first end face

Abstract: A &lgr;/2 resonator comprises an inner conductor formed hole having an inner conductor with both open-ends, formed therein, and &lgr;/4 resonators comprise inner conductor formed holes having inner conductors with one short-circuited ends and the other open ends, respectively. The resonators are coupled, whereby a terminal electrode connected to the vicinity of the one open end of one of the &lgr;/4 resonators functions as an unbalanced terminal, and terminal electrodes connected to both open ends of the &lgr;/2 resonator function as balanced terminals.

Abstract: Grooves are formed on the connection faces of the dielectric basic plates as a dielectric resonator, and also, an internal conductor is provided on the inside face, and coupling electrodes are formed on the other dielectric basic plate. These three dielectric basic plates are connected so that the coupling electrode effects capacity connection between internal conductors and the coupling electrode effects capacity connection between the internal conductors, whereby an earth electrode (external conductor) can be formed on almost full face on the reverse face side of the dielectric basic plate and the reduction of Qo of the resonator and the electromagnetic field leakage can be prevented.

Abstract: A dielectric filter, having a dielectric block with an outer surface including first and second end surfaces and a side surface extending between the first and second end surfaces; an external conductor disposed on the outer surface of the dielectric block, the external conductor substantially completely covering the outer surface; at least one hole extending through the dielectric body between the first and second end surfaces, the at least one hole having an inner surface; the at least one hole having a respective pair of internal conductors disposed on the corresponding inner surface thereof and conductively connected to the external conductor respectively at the first and second end surfaces, a respective non-conductive portion at the corresponding inner surface being spaced from both of the end surfaces and thereby separating the corresponding pair of internal conductors and defining a respective capacitance between the corresponding pair of internal conductors; a predetermined portion of the side surfac

Abstract: A dielectric filter, having a dielectric block with an outer surface including first and second end surfaces and a side surface extending between the first and second end surfaces; an external conductor disposed on the outer surface of the dielectric block, the external conductor substantially completely covering the outer surface; at least one hole extending through the dielectric body between the first and second end surfaces, the at least one hole having an inner surface; the at least one hole having a respective pair of internal conductors disposed on its corresponding inner surface and conductively connected to the external conductor respectively at the first and second end surfaces, a respective non-conductive portion at the corresponding inner surface being spaced from both of the end surfaces and thereby separating the corresponding pair of internal conductors and defining a respective capacitance between the corresponding pair of internal conductors; a predetermined portion of one of the first and se

Abstract: A dielectric antenna including a filter, comprising: a dielectric substrate; an antenna portion, comprising a radiation electrode having one short-circuited end and one open end and provided on or within the dielectric substrate; a filter portion comprising; at least one resonance electrode provided on or within the dielectric substrate, and a external coupling electrode in association with the resonance electrode; and the radiation electrode and the resonance electrode being coupled to each other.

Abstract: There is provided a dielectric filter, comprising: a plurality of resonance lines aligned in a dielectric block, in a dielectric subtrate or on a dielectric substrate; a plurality of input-output units respectively coupled to the plurality of resonance lines; at least one of the input-output units comprising a first external terminal capacitively coupled to one of the plurality of resonance lines, an external coupling line coupled to the one of the plurality of resonance lines to which the first external terminal is capacitively coupled, and a second external extending from an end of the external coupling line. In the above dielectric filter, input and output of signals are performed in a two-terminal type or a balance type, without using a balun.

Abstract: A method of adjusting characteristics of a dielectric filter including the following steps: forming a dielectric filter having a dielectric body, the dielectric body having an outer surface; forming an external conductor on the outer surface of the dielectric body; and forming at least one hole extending through the dielectric body, the at least one hole having a respective inner surface, and a respective internal conductor and a respective non-conductive portion at the inner surface; the outer surface of the dielectric body comprising first and second end surfaces and a side surface extending between the first and second end surfaces; the at least one hole extending through the dielectric body between the first and second end surfaces; the respective inner conductor being formed as a respective pair of internal conductors conductively connected to the external conductor at respective ends of the at least one hole, the respective non-conductive portion at the inner surface of the at least one hole being space

Abstract: A compact LED module capable of preventing electrostatic destruction is provided. This LED module has first, second, and third terminals; first and second light emitting diodes connected between the first and second terminals and also connected in inverse parallel to each other; and a third light emitting diode connected between the first or second terminal and the third terminal. The first light emitting diode is a green light emitting diode, the second light emitting diode is a blue light emitting diode, and the third light emitting diode is a red light emitting diode.

Abstract: A biaxially oriented polyester film comprising silica particles (A) having an average secondary particle size of 50-200 nm, an average primary particle size ratio (length/breadth) of 1.25-3.0 and the ratio of average primary particle size/standard deviation of primary particle size (d/&sgr;) of 0.5-5.0 in a proportion of 0.01-1% by weight, and inactive particles (B) having an average particle size of 300-1500 nm in a proportion of 0.01-1% by weight. The polyester film of the present invention can be adapted to a high speed feeding of a film or tape in the production line and stand the use of economical parts in an attempt to achieve decreasing the costs of tapes.

Abstract: The invention provides a dielectric filter, comprising: a dielectric block having substantially rectangular shape, said dielectric block including a first and a second opposed to each other and a third and a fourth opposed to each other and extending between said first and second surfaces; a plurality of through holes extending between said first and second surfaces; an inner conductor provided on an inner surface of said through holes except for a non-conductive portion, said non-conductive portion being disposed on said inner surface of said through holes in the vicinity of said first surface of said dielectric block; an outer conductor provided on said third and fourth surfaces of said dielectric block; and a line conductor provided on said first surface of said dielectric block, a part of said outer conductor provided on said third surface of said dielectric block and a part of said outer conductor provided on said fourth surface of said dielectric block being connected to each other via said line conduct

Abstract: A ?/2 resonator comprises an inner conductor formed hole having an inner conductor with both open-ends, formed therein, and ?/4 resonators comprise inner conductor formed holes having inner conductors with one short-circuited ends and the other open ends, respectively. The resonators are coupled, whereby a terminal electrode connected to the vicinity of the one open end of one of the ?/4 resonators functions as an unbalanced terminal, and terminal electrodes connected to both open ends of the ?/2 resonator function as balanced terminals.