Abstract: A radio-frequency filter device is provided with: a dielectric layer, a pair of conductive layers on both surfaces of the dielectric layer, shielding via conductors short-circuiting the conductive layers, a waveguide resonator portion formed by the shielding via conductors, another conductive layer on a surface of the dielectric layer, a pair of strip conductors on the dielectric layer, a pair of input and output coupling via conductors. The coupling via conductors pass through the conductive layer and the waveguide resonator portion without contacting with the conductive layer. One end of each coupling via conductor is short-circuited to the conductive layer, and the other end is connected to one strip conductor. By inputting a radio-frequency signal, fundamental and second-order resonant modes are excited in the waveguide resonator portion.

Abstract: An optical signal to electrical signal converter of the present invention comprises an optical waveguide propagating a modulated optical signal therethrough; a pair of electrodes disposed at positions opposite to each other sandwiching the optical waveguide with in a region where an electric field reaches that is generated in the optical waveguide when the optical signal propagates through the optical waveguide; and a resonator coupled to the pair of electrodes, the resonator receiving for excitation an electrical signal induced at the pair of electrodes by the electric field.

Abstract: An optical waveguide device has: photonic crystal regions 305, each having holes 304 arranged in a periodic array; and an optical waveguide 302. Within the waveguide 302, high refractive index portions 303 are arranged along the waveguiding direction. Each of the high refractive index portions 303 is generally interposed between a pair of holes 304 which are in symmetric positions with respect to the center axis. The center of gravity of every high refractive index portion 303 is shifted along the waveguiding direction from a midpoint of a line interconnecting centers of the pair of holes 304, and is located between a position which is 0.45 r away from the midpoint in the waveguiding direction and a position which is 0.25 r away from the midpoint in the opposite direction, where r is a radius of each hole 304.

Abstract: A photonic crystal device according to the present invention includes: a substrate 201; a periodic structure portion 206 formed in or on the substrate 201, the periodic structure portion 206 having a plurality of holes 2050 and 2051 arranged in a periodic array; at least one optical waveguide 202 formed in or on the substrate 201, the at least one optical waveguide 202 being adjacent to the periodic structure portion 206; and at least one optical resonator 203 formed in or on the substrate 201, the at least one optical resonator 203 being formed in a position away from the optical waveguide 202, with at least one hole 2051 among the plurality of holes 2050 and 2051 of the periodic structure portion 206 being interposed between the optical resonator 203 and the optical waveguide 202.

Abstract: An optical waveguide device has: photonic crystal regions 305, each having holes 304 arranged in a periodic array; and an optical waveguide 302. Within the waveguide 302, high refractive index portions 303 are arranged along the waveguiding direction. Each of the high refractive index portions 303 is generally interposed between a pair of holes 304 which are in symmetric positions with respect to the center axis. The center of gravity of every high refractive index portion 303 is shifted along the waveguiding direction from a midpoint of a line interconnecting centers of the pair of holes 304, and is located between a position which is 0.45 r away from the midpoint in the waveguiding direction and a position which is 0.25 r away from the midpoint in the opposite direction, where r is a radius of each hole 304.

Abstract: An RF circuit component according to the present invention includes a substrate with a principal surface and a plurality of resonators, including a first resonator, a second resonator and a third resonator, which are arranged on the principal surface of the substrate so as to be coupled in series together. Each of the first, second and third resonators is made of a conductor supported on the substrate. The resonant modes of each of the first, second and third resonators include two fundamental resonant modes that oscillate perpendicularly to each other within a plane that is defined parallel to the principal surface of the substrate. The second resonator is arranged between the first and third resonators, and the oscillation direction of one of the fundamental resonant modes of the second resonator defines an angle greater than 0 degrees but smaller than 90 degrees with respect to that of its associated fundamental resonant mode of the first resonator and/or the third resonator.

Abstract: A dielectric filter is provided with a dielectric multilayer structure formed by layering two or more dielectric layers which have different relative permittivities, at least one feeding electrode formed between any dielectric layers or formed inside of any dielectric layers of the dielectric multilayer structure, and a shield portion that covers the outer surface of the dielectric multilayer structure and is made of a conductive material placed so as to fit on the outer surface without any gap.

Abstract: A high-frequency circuit device includes a dielectric member 1, a shielding conductor 2 surrounding the dielectric member 1, a support member 3 for fixing and supporting the dielectric member 1, and a pair of transmission lines 4 each of which is formed of a microstrip-line. Each of the transmission lines includes a substrate 6 formed of a dielectric material, a strip conductor 5, and an earth conductor layer 9. An end portion of the strip conductor 5 faces part of the dielectric member 1 and functions as a coupling probe for input/output coupling. Each of the transmission lines 4 is formed of a strip line, a mictostrip line, a coplanar line or the like, and has low-loss when connected to a circuit board.

Abstract: A photonic crystal device according to the present invention includes: a substrate 201; a periodic structure portion 206 formed in or on the substrate 201, the periodic structure portion 206 having a plurality of holes 2050 and 2051 arranged in a periodic array; at least one optical waveguide 202 formed in or on the substrate 201, the at least one optical waveguide 202 being adjacent to the periodic structure portion 206; and at least one optical resonator 203 formed in or on the substrate 201, the at least one optical resonator 203 being formed in a position away from the optical waveguide 202, with at least one hole 2051 among the plurality of holes 2050 and 2051 of the periodic structure portion 206 being interposed between the optical resonator 203 and the optical waveguide 202.

Abstract: An RF circuit component according to the present invention includes a substrate with a principal surface and a plurality of resonators, including a first resonator, a second resonator and a third resonator, which are arranged on the principal surface of the substrate so as to be coupled in series together. Each of the first, second and third resonators is made of a conductor supported on the substrate. The resonant modes of each of the first, second and third resonators include two fundamental resonant modes that oscillate perpendicularly to each other within a plane that is defined parallel to the principal surface of the substrate. The second resonator is arranged between the first and third resonators, and the oscillation direction of one of the fundamental resonant modes of the second resonator defines an angle greater than 0 degrees but smaller than 90 degrees with respect to that of its associated fundamental resonant mode of the first resonator and/or the third resonator.

Abstract: A high-frequency circuit device includes a dielectric member 1, a shielding conductor 2 surrounding the dielectric member 1, a support member 3 for fixing and supporting the dielectric member 1, and a pair of transmission lines 4 each of which is formed of a microstrip-line. Each of the transmission lines includes a substrate 6 formed of a dielectric material, a strip conductor 5, and an earth conductor layer 9. An end portion of the strip conductor 5 faces part of the dielectric member 1 and functions as a coupling probe for input/output coupling. Each of the transmission lines 4 is formed of a strip line, a mictostrip line, a coplanar line or the like, and has low-loss when connected to a circuit board.

Abstract: A dielectric filter is provided with a dielectric multilayer structure formed by layering two or more dielectric layers which have different relative permittivities, at least one feeding electrode formed between any dielectric layers or formed inside of any dielectric layers of the dielectric multilayer structure, and a shield portion that covers the outer surface of the dielectric multilayer structure and is made of a conductive material placed so as to fit on the outer surface without any gap.

Abstract: An optical signal to electrical signal converter of the present invention comprises an optical waveguide propagating a modulated optical signal therethrough; a pair of electrodes disposed at positions opposite to each other sandwiching the optical waveguide with in a region where an electric field reaches that is generated in the optical waveguide when the optical signal propagates through the optical waveguide; and a resonator coupled to the pair of electrodes, the resonator receiving for excitation an electrical signal induced at the pair of electrodes by the electric field.

Abstract: A high-frequency circuit device includes a dielectric member 1, a shielding conductor 2 surrounding the dielectric member 1, a support member 3 for fixing and supporting the dielectric member 1, and a pair of transmission lines 4 each of which is formed of a microstrip-line. Each of the transmission lines includes a substrate 6 formed of a dielectric material, a strip conductor 5, and an earth conductor layer 9. An end portion of the strip conductor 5 faces part of the dielectric member 1 and functions as a coupling probe for input/output coupling. Each of the transmission lines 4 is formed of a strip line, a mictostrip line, a coplanar line or the like, and has low-loss when connected to a circuit board.

Abstract: An optical modulator according to the present invention includes an optical waveguide 2a to 2d made of a material with an electro-optic effect and a modulating electrode 3 for applying a modulating electric signal to light propagating through the optical waveguide 2a to 2d. The modulator further includes a periodic structure, of which the equivalent refractive index changes periodically in a light propagation direction and which can reduce the group velocity of the light propagating through the optical waveguide 2a, 2b.

Abstract: The resonator of the present invention includes a cylindrical dielectric and a conductor film covering the surface of the dielectric in close contact therewith. The conductor film is constructed of a cylindrical portion and two flat portions, and is formed by subjecting the surface of the dielectric to metallization or the like. With the conductor film formed in close contact with the dielectric, deterioration of the Q value and the like caused by instability of connection at the corners can be suppressed even when a radio frequency induced current flows from the cylindrical portion over the two flat portions.

Abstract: A dielectric resonator filter comprises dielectric resonators, an enclosure having a main body, a lid, and partition walls, interstage-coupling tuning windows, interstage-coupling tuning bolts, input/output terminals, and input/output coupling probes. Resonance-frequency tuning members each composed of a conductor plate and a bolt coupled integrally thereto are attached to the enclosure lid. Undesired-mode suppressing means such as rings attached to the bolts of the resonance-frequency tuning members or bolts attached to the conductor plates or to the enclosure lid are disposed in an undesired-mode excitation space, whereby the occurrence of a disturbed characteristic in the pass band (or stop band) is suppressed.

Abstract: An optical modulator includes an optical waveguide, a modulating electrode, a conductive layer, an electric signal input section, and connector members. At least a portion of the optical waveguide is made of an electro-optic material. The modulating electrode includes a first conductor line and a second conductor line, which are coupled together electromagnetically, and applies a modulating electric field to a portion of the optical waveguide. The conductive layer forms a first microstrip line with the first conductor line and a second microstrip line with the second conductor line, respectively. Through the electric signal input section, an RF modulating signal is supplied to the modulating electrode. The connector members connect the first and second conductor lines together at both ends. In this optical modulator, the first and second conductor lines function as an odd-mode resonator for the RF modulating signal.

Abstract: The resonator of the present invention includes a cylindrical dielectric and a conductor film covering the surface of the dielectric in close contact therewith. The conductor film is constructed of a cylindrical portion and two flat portions, and is formed by subjecting the surface of the dielectric to metallization or the like. With the conductor film formed in close contact with the dielectric, deterioration of the Q value and the like caused by instability of connection at the corners can be suppressed even when a radio frequency induced current flows from the cylindrical portion over the two flat portions.

Abstract: A dielectric resonator filter comprises dielectric resonators, an enclosure having a main body, a lid, and partition walls, interstage-coupling tuning windows, interstage-coupling tuning bolts, input/output terminals, and input/output coupling probes. Resonance-frequency tuning members each composed of a conductor plate and a bolt coupled integrally thereto are attached to the enclosure lid. Undesired-mode suppressing means such as rings attached to the bolts of the resonance-frequency tuning members or bolts attached to the conductor plates or to the enclosure lid are disposed in an undesired-mode excitation space, whereby the occurrence of a disturbed characteristic in the pass band (or stop band) is suppressed.