Nippon Telegraph and Telephone Corporation

Ntt Electronics Corporation

Hideyuki Nosaka

Munehiko Nagatani

Teruo Jo

Hiroshi Hamada

Hiroyuki Fukuyama

Koichi Murata

Naoki Miura

Hiroshi Yamazaki

Yutaka Miyamoto

Makoto Nakamura

Kenji Tanaka

Yasushi Takatori

Koichi Ishihara

Riichi Kudo

Takayuki Kobayashi

Munehiro Matsui

Naoki Fujiwara

Masanori Nakamura

Masato Mizoguchi

Etsushi Yamazaki

Masahiro Suzuki

Hiroshi Koizumi

Kimikazu Sano

Shinsuke Nakano

Naoki Terao

Hiroaki Katsurai

Akihide Sano

Shogo Yamanaka

Masafumi Nogawa

Toshiki Kishi

Masatoshi Tobayashi

Go Itami

Takatomo Enoki

Kiyomitsu Onodera

Eisuke Tsuchiya

Il-Min Yi

Hiroyuki Uzawa

Eiji Yoshida

Takashi Saida

Shin Kamei

Kengo Horikoshi

Hiroto Kawakami

Nobuhiro Kikuchi

Tadao Nakagawa

Toshihiro Itoh

Tomoyoshi Kataoka

Shigeki Aisawa

Akihiro Yamagishi

Eiichi Yamada

Mikio Yoneyama

Hideki Kamitsuna

Hitoshi Wakita

Yo Yamaguchi

Yasunobu Inabe

Yves Bouvier

Miwa Mutoh

Akira Minakawa

An embodiment includes an output circuit with transistors and a withstand voltage protection circuit. The withstand voltage protection circuit includes resistors connected between an output signal terminal on the positive phase side and an output signal terminal on the negative phase side. A switch includes an NMOS transistor having a gate terminal connected to the connection point of the resistors, a drain terminal connected to the bias voltage, and a source terminal connected to the base terminal of the transistor.

Driver circuit

A delta sigma modulator includes: an integrator that integrates differences between input signals and output signals of the delta sigma modulator; and a clocked comparator that outputs the output signals that are results of comparison between an output of the integrator and a threshold, at a timing synchronized with a clock signal. The integrator includes an operational amplifier, input resistors, feedback capacitors, and compensation inductors.

Delta sigma modulator

The driver circuit includes DC cut capacitors, an input buffer, input termination resistors connected in series between differential input signal terminals and an ESD protection circuit connected to a connection point of the input terminal resistors. The ESD protection circuit includes diodes.

Arranged on a surface of a substrate are a patch conductor that radiates an electromagnetic field having been fed, a feed line that feeds the patch conductor with the electromagnetic field having been input, two slits parallel to the feed line on both sides of a connection part of the feed line toward an inner side of the patch conductor, and a ring conductor at a space from the patch conductor with an interposition of a gap to surround an outer periphery of the patch conductor. Accordingly, an electric capacitance can be formed between the patch conductor and the ring conductor, and when achieving impedance matching with the feed line, adjustment can be performed using the size of the ring conductor and the gap.

Circuit integrated antenna

A distributed amplifier includes: a transmission line having an input end that an input signal is input to; a transmission line having an output end that an output signal is output from; an input termination resistor connected to an end terminal of the transmission line; a plurality of unit cells arranged along the transmission lines, and having input terminals connected to the transmission line and output terminals connected to the transmission line; and a variable current source having one end connected to the end terminal of the transmission line and another end connected to a power supply voltage, and capable of adjusting a current amount between the transmission line and the power supply voltage.

Distributed circuit

A voltage setting circuit includes a frequency comparator that compares the oscillation frequencies of a first distributed voltage-controlled oscillator and a second distributed voltage-controlled oscillator and a frequency determination circuit that determines the levels of the oscillation frequencies of the first distributed voltage-controlled oscillator and the second distributed voltage-controlled oscillator. The bias to be supplied to the first distributed voltage-controlled oscillator and the bias to be supplied to the second distributed voltage-controlled oscillator are determined in accordance with a result of the determination. The bias at a time when the levels of the oscillation frequencies are reversed is determined to be the optimum bias, and the optimum bias is supplied to the core circuit.

Voltage setting circuit, semiconductor integrated circuit and voltage setting method

An amplifier circuit comprises a variable degeneration circuit connected to emitter terminals of transistors, and a variable negative capacitance circuit connected to differential output signal terminals. The variable degeneration circuit includes a variable capacitor and a resistor. The variable negative capacitance circuit, which is a variable current source, includes a transistor, a capacitor, and a variable current source. The variable negative capacitance circuit includes transistors, a capacitor, and variable current sources.

Amplifier and driver circuit

A sampling circuit includes: a first transmission line that transmits an input signal; a second transmission line that transmits a clock signal; and a plurality of sample-hold circuits that are connected to the first and second transmission lines at a constant line distance, wherein the first transmission line transmits the input signal at a first propagation time for each of the line distances, and the second transmission line transmits the clock signal at a second propagation time that is a sum of a preset sampling interval and the first propagation time for each of the line distances.

Sampling circuit

A driver circuit includes a differential pair of transistors that amplify differential input signals and output the amplified differential input signals from signal output terminals, a current source that supplies a constant current to the differential pair of transistors, a switch that stops the current supply from the current source to the differential pair of transistors during a shutdown mode period, capacitors each having one end connected to the ground, a switch that connects the capacitor to the signal output terminal during the shutdown mode period and disconnects the capacitor from the signal output terminal during an amplification mode period, and a switch that connects the capacitor to the signal output terminal during the shutdown mode period and disconnects the capacitor from the signal output terminal during the amplification mode period.

Stub conductors are disposed so as to surround an outer periphery of a patch conductor and be spaced from the patch conductor with a gap positioned between the stub conductors and the patch conductor.

The DML driver includes: a post driver which supplies a driving current to the LD; and a pre-driver which drives the post driver in response to a modulated signal. The pre-driver has a transistor, a peaking inductor, a peaking inductor, a group delay inhibition inductor, and a peaking capacitor.

DML driver

A clock generation circuit includes a mode-locked laser that generates an optical pulse, a photodiode that photoelectrically converts the optical pulse generated by the mode-locked laser, and a filter that attenuates at least one of a DC component and a harmonic component of the mode-locked laser included in an electric signal output from the photodiode.

Clock generation circuit

A permittivity measuring method includes measuring a set of phases at sampling frequencies of at least three points in each of a first-half portion and a second-half portion of a phase characteristic of electromagnetic waves that passed through a measurement target, if the mode of the phase changes of both sets of phases belongs to a phase group in which change of the at least three points in the first half and change of at least three points in the second half are both monotonic change, maximal values, or minimal values, calculating the permittivity using the phase slope of the phases in the first-half portion and the phases in the second-half portion, and if the mode of the phase changes does not belong to the phase group, calculating the permittivity by fitting the phases of either the first half or the second half to a quadratic function.

Dielectric constant measurement method, dielectric measurement device and dielectric measurement program

An embodiment is a multiplexer including a first distributed amplifier with an impedance matched to 50Ω, the first distributed amplifier configured to receive a first signal and output a first amplified signal, a second distributed amplifier with an impedance matched to 50Ω, the second distributed amplifier configured to receive a second signal and output a second amplified signal, and a passive multiplexer configured to multiplex the first amplified signal and the second amplified signal, and output a multiplexed signal to a signal output terminal, the passive multiplexer including a first resistor having a first end to receive the first amplified signal, a second resistor having a first end to receive the second amplified signal, and a third resistor having a first end connected to second ends of the first and second resistors and a second end connected to the signal output terminal.

Multiplexer

A gain adjustment unit constituted by a distribution switch having a control terminal is provided in an input unit of an amplifier circuit. One end of a coupler is connected to an output line of the amplifier circuit, another end of the coupler is connected to an anode of a diode, and a monitor terminal is connected via a low-pass filter to a cathode of the diode. The anode of the diode is unbiased.

Variable gain amplifier

Growing community of inventors

Tokyo, Japan

Hideyuki Nosaka