摘要:
A method and device for adequately controlling the DC bias of each of the optical modulating sections of an optical modulator even while the optical modulator is operating in normal mode and even with a simple structure. An optical modulator bias controller (B) for controlling the DC bias of each optical modulating section of an optical modulator (1) is characterized by comprising DC bias application means (3) for applying a DC bias to each of the optical modulating sections, a low-frequency signal superimposing circuit (2) for superimposing a low-frequency signal fB with a specific frequency on a modulating signal b applied to each optical modulating section, optical sensing means (9) for sensing a change of the intensity of the light wave passing through the combining section, and bias control means (4) for extracting the change of the intensity of light corresponding to the low-frequency signal from the optical sensing means and controlling the DC bias application means according to the extracted change of the intensity of light.
摘要:
An optical modulator is provided which includes: an optical splitting part that splits an input light wave into two light waves; two optical waveguides that propagate the two light waves into which the input light wave is split, respectively; a first SSB modulating part that is provided in one of the two optical waveguides and modulates a light wave, which propagates into the first SSB modulating part, with a carrier frequency so that the light wave is converted into a different light wave having a single side band; a second SSB modulating part that is provided in the other of the two optical waveguides and modulates a light wave, which propagates into the second SSB modulating part, with a data signal in order to generate a signal light wave having a different single side band; and an optical combining part that combines the light wave modulated by the first SSB modulating part with the signal light wave generated by the second SSB modulating part.
摘要:
In a radio optical fusion communication system with the integration of an optical fiber transmission path and a radio propagation path, wherein by first and second light sources, an intermediate-frequency signal generating means for generating a modulating signal at an intermediate frequency band, a modulator for modulating an optical signal from the first light source into an SSB modulated optical signal using the intermediate-frequency signal, and an optical mixer for mixing the modulated optical signal with the optical signal from the second light source to obtain an optical transmission signal in a base station, the frequency of either of the optical signals is controlled such that the difference in frequency between the optical signals is a desired frequency of a modulated radio signal, thus switching the frequency channel of the modulated radio signal in the radio propagation path.
摘要:
A method, computer, and recording medium storing a program are provided which, based on local optimal solutions, more efficiently calculate an optimal global optimal solution in a global operating area. System calculates the global optimal solution by solving, using a genetic algorithm based on the local optimal solutions and the initial values, an equation, which should be satisfied by the plurality of design variables, by obtaining the plurality of combinations of design variables composing local optimal solutions for each design variable respectively calculated for each of a plurality of combinations of a plurality of operating states, and by obtaining initial values for the plurality of combinations of design variables used for calculating the global optimal solution.
摘要:
Microorganism sensors used in environment assessment technologies and the like, instead of being used to detect environmental components and determine their concentrations, were used as tools to evaluate the ability of target soil microorganisms to adapt to various field soil environments, and comparative studies were performed. As a result, the present inventors found that by using the microorganism sensors to examine the growth potential of general soil microorganisms and pathogenic microorganisms in ecosystems, the balance in the soil ecosystems could be monitored, and further, the risk of disease occurrence and the bio-controlling effect of general soil microorganisms could also be determined.
摘要:
There is provided a semiconductor testing apparatus comprising a current measuring portion which converts a load current quantity at the time of application of a relatively high test voltage to a DUT to fall within a low-voltage range, and then subjects the low-voltage range to quantization conversion with a predetermined measurement resolution even when the relatively high test voltage is applied to the DUT. This is a differential voltage measuring apparatus comprising: an applied voltage source which applies a predetermined constant voltage to a load device; current/voltage converting means for directly inserting a predetermined resistance between an output end of the applied voltage source and the load device, and converts a quantity of a current flowing through the load device into a voltage; and current measuring means which switches and receives a common mode voltage and a detection voltage in time series, shifts the received voltages to predetermined low voltages, and outputs low-voltage measurement data obtained by receiving each of the shifted voltages and subjecting this voltage to quantization conversion.
摘要:
A power supply device for supplying source current to an electronic device comprises: a current output unit for outputting output current including at least the source current as a component of the current thereof; a connection resistor which electrically connects the current output unit and the electronic device for supplying the source current to the electronic device; a low-pass filter for allowing the output voltage of the current output unit to pass through; a differential detection unit for detecting the electric potential difference between the output voltage of the low-pass filter and the electric potential at the device-side terminal of the connection resistor; and a parallel load unit which is connected to the output terminal of the current output unit in parallel with the connection resistor, and which has a function of consuming a partial current which is a part of the output current of the current output unit in a case that the electric potential difference detected by the differential detection unit is smaller than a predetermined value, and which has a function of stopping reception of the partial current in a case that the electric potential difference detected by the differential detection unit has become greater than a predetermined value.
摘要:
There is provided a semiconductor testing apparatus comprising a current measuring portion which converts a load current quantity at the time of application of a relatively high test voltage to a DUT to fall within a low-voltage range, and then subjects the low-voltage range to quantization conversion with a predetermined measurement resolution even when the relatively high test voltage is applied to the DUT. This is a differential voltage measuring apparatus comprising: an applied voltage source which applies a predetermined constant voltage to a load device; current/voltage converting means for directly inserting a predetermined resistance between an output end of the applied voltage source and the load device, and converts a quantity of a current flowing through the load device into a voltage; and current measuring means which switches and receives a common mode voltage and a detection voltage in time series, shifts the received voltages to predetermined low voltages, and outputs low-voltage measurement data obtained by receiving each of the shifted voltages and subjecting this voltage to quantization conversion.
摘要:
A testing device that tests an electronic device includes a detection-voltage outputting unit operable to output a current detection voltage based on a power source current that the electronic device receives from a power source, a transmission line operable to transmit the current detection voltage, a detection amplifier operable to output an amplifier output voltage based on the current detection voltage received through the transmission line, a switching unit operable to select whether the current detection voltage is supplied to the detection amplifier, an integrator operable to output an integral value that is obtained by integrating values based on the amplifier output voltage, and a decision unit operable to decide whether the electronic device is good or bad based on the integral value.
摘要:
An optical waveguide modulator 40 has a substrate 1 made of a material with an electrooptic effect, an optical waveguide 2 to guide a lightwave 2, a travelling wave-type signal electrode 3 and the ground electrodes 4 to control the lightwave. Moreover, it has a buffer layer 6, at least a part thereof being embedded in the superficial layer of the substrate 1, having a larger width “W” than a width “&ohgr;” of the travelling wave-type signal electrode 3 only under the signal electrode 3 and its nearby part.