Abstract: To provide a catalyst capable of hydrotreating a hydrocarbon oil with high desulfurization activity. A hydrotreating catalyst for a hydrocarbon oil includes: an inorganic composite oxide carrier including alumina as a main component; and an active metal component supported on the carrier, the active metal component including, as active metal species, a first metal which is at least one of molybdenum and tungsten, and a second metal which is at least one of cobalt and nickel, the hydrotreating catalyst for having a Lewis acid amount and a Brönsted acid amount per unit surface area of 0.80 ?mol/m2 or more and 0.03 ?mol/m2 or less, respectively, as measured by pyridine desorption at 250° C. and a BET single-point method.

Abstract: An object is to avoid a deadlock in a PLL. A PLL synthesizer includes a PLL circuit that includes a voltage control oscillation circuit configured to control an oscillation frequency according to a control voltage, an oscillation frequency storage unit configured to previously store the oscillation frequency at a first temperature, a control voltage setting unit configured to set a control voltage based on a difference between the oscillation frequency at a second temperature and the stored oscillation frequency, and a calibration processing unit configured to calibrate the voltage control oscillation circuit in a state in which the control voltage is set so that the oscillation frequency will become a predetermined frequency.

Abstract: A quadrature modulator includes a local oscillator oscillating at an oscillation frequency equal to 4/(2N+1) times a carrier frequency where N is a natural number, a frequency conversion block for multiplying the oscillation frequency by a factor of (2N+1)/2, a divider for dividing the multiplied oscillation frequency to output a pair of orthogonal carrier waves, first and second multipliers for modulating the carrier waves with a digital baseband signal, and an adder for adding the modulated carrier waves to output a carrier signal having the carrier frequency. The frequency conversion block includes a divider for dividing the oscillation frequency, N frequency mixers cascaded from one another and a band-pass-filter, which are cascaded in this order.

Abstract: There is disclosed a phase shifter using a polyphase filter, which achieves a broad band, suppresses errors in both amplitude and phase, and achieves low power consumption. A driving section includes a voltage-to-current conversion circuit for converting a voltage value of an input signal Si into a current value, and outputting an input current signal Ci. An RC polyphase filter 2 outputs a corresponding polyphase phase-shifted current signal Co according to supplying of the input current signal Ci. A load circuit 3 includes a polyphase current-to-voltage conversion circuit for converting a current value of the polyphase phase-shifted current signal Co into a voltage value, and outputting an output signal Vo.

Abstract: The differential amplifier circuit of the invention comprises operational amplifiers 3 and 4 having the negative inputs connected to input terminals 1 and 2 respectively, transistors 21 and 22 having the bases connected to each of the outputs of the operational amplifiers 3 and 4 respectively, constant current sources 41 and 42 connected between each emitter of the transistors 21 and 22 and a ground terminal 8 respectively, constant current sources 43 and 44 connected between each collector of the transistors 21 and 22 and a power supply terminal 7 respectively, a resistor 31 connected between the collectors of the transistors 21 and 22, transistors 23 and 24 having the emitters connected to each emitter of the transistors 21 and 22 respectively and the bases commonly connected to each other, and load resistors 32 and 33 connected between each collector of the transistors 23 and 24 and the power supply terminal 7 respectively.

Abstract: There is disclosed a phase shifter using a polyphase filter, which achieves a broad band, suppresses errors in both amplitude and phase, and achieves low power consumption. A driving section includes a voltage-to-current conversion circuit for converting a voltage value of an input signal Si into a current value, and outputting an input current signal Ci. An RC polyphase filter 2 outputs a corresponding polyphase phase-shifted current signal Co according to supplying of the input current signal Ci. A load circuit 3 includes a polyphase current-to-voltage conversion circuit for converting a current value of the polyphase phase-shifted current signal Co into a voltage value, and outputting an output signal Vo.

Abstract: A quadrature modulator includes a local oscillator oscillating at an oscillation frequency equal to 4/(2N+1) times a carrier frequency where N is a natural number, a frequency conversion block for multiplying the oscillation frequency by a factor of (2N+1)/2, a divider for dividing the multiplied oscillation frequency to output a pair of orthogonal carrier waves, first and second multipliers for modulating the carrier waves with a digital baseband signal, and an adder for adding the modulated carrier waves to output a carrier signal having the carrier frequency. The frequency conversion block includes a divider for dividing the oscillation frequency, N frequency mixers cascaded from one another and a band-pass-filter, which are cascaded in this order.

Abstract: A variable gain amplifier circuit enables the minimum gain to be established easily without changing DC voltage of output terminal at the time when the gain is to be variable. The variable gain amplifier circuit is provided with an input differential circuit consisting of a first and a second transistors whose respective bases are connected to input terminals, and whose respective emitters are connected to constant-current source, and a gain control differential circuit consisting of a third to an eighth transistors 9, 14, 10, 11, 12, and 13 which are connected mutually such that base, collector, and emitter become required relationship. Further, the variable gain amplifier circuit is provided with a first load resistor connected between collector of the third, fifth, and seventh transistors 9, 10, and 12, and a first power supply terminal, and a second load resistor connected between collector of the sixth, eighth, and fourth transistors 11, 13, and 14.

Abstract: A phase shift circuit includes a CR phase shifter for receiving an input signal to output a pair of first signals having a 90.degree. phase difference therebetween, a pair of variable-gain amplifiers for receiving the first signals to output a pair of second signals, an adder for adding both the second signals to output a sum signal, a subtracter for outputting a difference signal between the second signals, and a phase error detector for detecting the phase difference between the outputs from the adder and the subtracter to output a pair of gain control signal based on the phase difference. The gain control signal is fed-back to the variable-gain amplifier to control the ratio between the gains of the variable-gain amplifiers.