Abstract: The reflection loss characteristic of a dielectric filter provided with a plurality of stages of resonators is measured, pole frequencies and a balance of heights of peaks in the reflection loss characteristic are sought, and, based on the pole frequencies and the balance of peaks, the part of the filter to be adjusted and the degree of adjustment are determined with reference to a database constructed in advance.

Abstract: A dielectric filter and a dielectric duplexer have structures for coupling between resonators, in which a range for determining the coupling strength between the resonators can be broadened and the polarity of the coupling can be changed. In addition, a communication apparatus incorporating the dielectric filter or the dielectric duplexer can be provided. Inside a dielectric member, resonance line holes having resonance lines formed on the inner surfaces thereof are disposed. Both ends of each of the resonance line holes are open-circuited. The inner diameter of each of the resonance line holes is changed at some point in the longitudinal direction of each resonance line to form a stepped part.

Abstract: There is disclosed a dielectric filter, comprising: a dielectric block; a plurality of inner conductor formed holes provided in the dielectric block; inner conductors provided on the inner walls of the inner conductor formed holes; and outer conductor provided on the outer surface of the dielectric block so as to have one opening-face as an open-face of the inner conductor formed holes, and have the other opening-face thereof as a short-circuiting-face; wherein the sectional shape of the inner conductor formed holes are substantially constant in the range from the open-face to the short-circuiting-face, and a step is provided in the intermediate portion of the center axis of at least one inner conductor formed hole.

Abstract: An optical semiconductor device module includes an optical semiconductor device package, an optical semiconductor device such as a laser diode accommodated in the package, and a cooling area on an inner face of a metal bottom plate of the package and operable to cool the optical semiconductor device. A groove permitting molten solder to flow therein is formed in at least part of the solder joint area on the inner face of the metal bottom plate.

Abstract: A filter unit comprises a wideband bandpass filter; at least one band-elimination filter having a stop band within the passband of the bandpass filter, so that the passband is divided into a plurality of pass bands by the stop band; and the wideband bandpass filter and the band-elimination filter being disposed in a single dielectric member. Since the passband of a wideband bandpass filter is divided into a plurality of pass bands by stop bands of one or more band-elimination filters, signals having frequencies corresponding to these divided pass bands are able to pass through the filter unit simultaneously.

Abstract: A semiconductor laser module is packaged on a mounting substrate through a thermal diffusion sheet member. The thermal diffusion sheet member is that having thermal conductivity where thermal conductivity in the surface direction is greater than that in the thickness direction. Specifically, the thermal diffusion sheet member is graphite, for example, and has a thermal conductivity of 300 W/m.K or greater in the surface direction.

Abstract: In a dielectric filter, from the top surface to the bottom surface of a substantially rectangular dielectric block, inner-conductor holes are formed. On the inner surfaces of the inner-conductor holes, inner conductors are formed except where non-conductor portions are formed in proximity to one of the top and bottom surfaces, in which the apertures of the inner-conductor holes are formed. On the outer surface of the dielectric block, an outer conductor is formed substantially over the entire outer surface, and input and output electrodes isolated from the outer conductor are coupled with the non-conductor portions in the respective inner-conductor holes at the ends of the dielectric block in the direction of array of the inner-conductor holes.

Abstract: An intermediate frequency signal of an OFDM signal received by a tuner (2) is multiplied by a carrier wave by a multiplier (3) and a multiplier (4) to thereby generate an OFDM signal in a base band. The OFDM signal in the base band is FFT processed by an FFT circuit (5) and a resultant signal is outputted to a dividing circuit (10) and a pilot signal extracting circuit (8) in an equalizing circuit (13). A pilot signal extracted by the pilot signal extracting circuit (8) is supplied to an interpolating filter (9) and subjected to an interpolating process. An amplitude component and a phase component in the pilot signal are supplied to the dividing circuit (10). The dividing circuit (10) divides the signal input from the FFT circuit (5) by the amplitude and phase supplied from the interpolating filter (9) and a resultant signal is output to a demapping circuit (11).

Abstract: An optical semiconductor element package including a housing, electric signal input and output wiring boards, and external leads. The housing has a metal frame and a metal bottom plate, for storing optical semiconductor elements. The electric signal input and output wiring boards are arranged in the housing at positions so that the optical semiconductor elements are not existent right above and right below the boards. The external leads are drawn to the outside through the side wall of the metal frame. The wiring boards are connected to the external leads and to the optical semiconductor elements by bonding wires. The input and output of an electric signal between the outside and the optical semiconductor elements are carried out through the bonding wires, the wiring boards and the external leads.

Abstract: The present invention provides a process for preparing a phospholipid in an aqueous system in which hydrolysis is extremely controlled, and the synthetic yield is improved.

Abstract: A dielectric duplexer includes a substantially rectangular dielectric block. The dielectric block includes inner-conductor-containing holes each having an inner conductor on the inner surfaces thereof, and inner-conductor-unformed portions on which the inner conductors are not formed are formed in the vicinity of first ends of the inner-conductor-containing holes. The dielectric block further includes an outer conductor and input/output electrodes which are formed on the outer surface thereof, and the input/output electrodes are separated from the outer conductor. A through-hole having a short circuited electrode formed on the inner surface thereof is provided between two of the inner-conductor-containing holes so as to run from the mounting surface to the surface opposite thereto.

Abstract: The reflection loss characteristic of a dielectric filter provided with a plurality of stages of resonators is measured, pole frequencies and a balance of heights of peaks in the reflection loss characteristic are sought, and, based on the pole frequencies and the balance of peaks, the part of the filter to be adjusted and the degree of adjustment are determined with reference to a database constructed in advance.

Abstract: The invention provides a composite dielectric filter device that can easily improve the isolation characteristics between mutually adjacent filters, even when using a compact dielectric block to miniaturize the entire configuration of the device. The invention also provides a communication apparatus incorporating the filter device. In the filter device, inner conductor holes are arranged inside a single dielectric block, and an outer conductor is formed on outer faces of the dielectric block. Additionally, an outer-conductor-free portion is formed at the boundary between a transmission filter and a reception filter formed by the inner conductor holes.

Abstract: The time required for switch the channel can be remarkably curtailed. When broadcasting signals through a plurality of information channels with an OFDM system, the plurality of information channels are multiplexed in the sense of frequency and collectively subjected to IFFT modulation for connected transmission instead of subjecting the plurality of information channels independently to OFDM modulation for transmission. With this arrangement, the efficiency of exploitation of frequencies is improved. According to the invention, the OFDM frames are synchronized for each information channel for the purpose of connected transmission. Then, the OFDM receiver can switch the information channel for signal reception, maintaining the frame synchronizing signals.

Abstract: An optical semiconductor device module includes an optical semiconductor device package, an optical semiconductor device such as a laser diode accommodated in the package, and a cooling device such as a Peltier device solder-joined to a solder joint area on an inner face of a metal bottom plate of the package and operable to cool the optical semiconductor device. A groove permitting molten solder to flow therein is formed in at least part of the solder joint area on the inner face of the metal bottom plate.

Abstract: A method of adjusting characteristics of an electronic part such as a dielectric filter. Values of predetermined characteristics of the electronic part are measured. An electromagnetic field simulation is performed to determine characteristic values of the electronic part which would be obtained when a plurality of structural parameters, corresponding to dimensions of selected portions of the electronic part are varied. Amounts of variations of the parameter values from the design parameter values which have to be made to make the difference between the measured characteristic values and the design characteristic values fall within a predetermined range of allowable error are determined based on the results of the simulation. The selected portions of the electronic part corresponding to the structural parameters are adjusted by the amounts of variations.

Abstract: A dielectric filter capable of easily obtaining desired filter characteristics by strongly coupling mutually adjacent resonators with high accuracy even when reducing the height of the entire filter. In this filter, inside a dielectric block, there are disposed inner-conductor-formed holes in which inner conductors are formed on the inner surfaces of the holes. Coupling electrodes are arranged on an outer surface of the dielectric block and are electrically connected to the inner conductors. Additionally, the coupling electrodes are extended, for example, from the edge of an opening surface of the dielectric block which contains the open ends of the inner-conductor-formed holes, onto a side surface which is disposed parallel to a direction in which the inner-conductor-formed holes are aligned. The invention also provides a duplexer and a communication apparatus using the dielectric filter.

Abstract: A demodulation method and apparatus applicable to e.g., digital broadcast in accordance with the orthogonal frequency division multiplexing system (OFDM), in which synchronization of carrier frequency correction control of OFDM signals can be maintained in stability. Based on the information indicating the demodulation reliability, such as the result of cumulative addition of CP values, supplied from the wide range fc error—CPE calculating circuit (10), or the transmission control signal detection information, supplied from the transmission control information demodulating communication (17), a holding circuit (14) verifies whether or not the wide range fc error—CPE calculating circuit (10) is making an erroneous detection operation. If the wide range fc error—CPE calculating circuit (10) is making an erroneous detection operation, the holding circuit (14) outputs the wide range fc error output in the previous symbol, without updating the information on the wide range fc error.

Abstract: The time required for switch the channel can be remarkably curtailed. When broadcasting signals through a plurality of information channels with an OFDM system, the plurality of information channels are multiplexed in the sense of frequency and collectively subjected to IFFT modulation for connected transmission instead of subjecting the plurality of information channels independently to OFDM modulation for transmission. With this arrangement, the efficiency of exploitation of frequencies is improved. According to the invention, the OFDM frames are synchronized for each information channel for the purpose of connected transmission. Then, the OFDM receiver can switch the information channel for signal reception, maintaining the frame synchronizing signals.

Abstract: A reception apparatus for OFDM signals having a short initial rise time since start of reception until outputting the sound and/or a picture. An OFDM reception apparatus 1 of the ISDB-T standard presets the TMCC information at the outset in a memory 19 in association with each broadcasting station. This TMCC information contains the information on the RF frequency and the guard interval length, time interleaving pattern information, the information on the carrier modulation scheme and the information on the code rate of the convolutional code. When a user selects a broadcasting station, a control circuit 18 reads out the TMCC information associated with the broadcasting station from the memory 19. The control circuit 18 affords the read-out TMCC information to each circuit to set e.g., the guard interval or the carrier modulation scheme.