Mitsubishi Electric Corporation

Hideyuki Ohashi

Hiroshi Aruga

Yuichi Sasaki

Yoshihiro Akeboshi

Koji Shibuya

Ayumi Sakai

Naoto Oka

Fujiyuki Nakamoto

Tetsuro Komura

A printed circuit board includes a line formation layer including a differential line having a first conductor and a second conductor, a first component for a countermeasure against a surge, a first connection conductor having one end connected to the first conductor and another end connected to the first component, a second component for a countermeasure against a surge, a second connection conductor having one end connected to the second conductor and another end connected to the second component, a ground layer, and a dielectric mounted between the line formation layer and the ground layer. Lengths of the first conductor and second conductor are adjusted based on a difference of capacitance values in the circuit board.

Printed circuit board to suppress deterioration of an electrical balance in a differential line

A transmission device that establishes efficient match with an impedance mismatch section of a differential transmission system. The transmission device includes: a differential driver; a differential receiver; a differential line that connects between the differential driver and the differential receiver, the differential line including in-phase signal wiring and inverted-phase signal wiring; a delay increasing structure interposed in the differential line at an upstream of the impedance mismatch section; and a delay increasing structure interposed at a downstream of the impedance mismatch section. The delay increasing structure is interposed only in one of the in-phase signal wiring and the inverted-phase signal wiring, and the delay increasing structure is interposed only in another of the in-phase signal wiring and the inverted-phase signal wiring.

Transmission device

Provided is an optical module in which wiring density may be reduced to ensure isolation between lines to reduce crosstalk. A flexible printed circuit includes: dielectric layers; a first pattern facing portion including a first ground conductor pattern and a first wiring pattern electrically connected to an electric terminal, which are facing each other through the dielectric layer; and a second pattern facing portion including a second ground conductor pattern and a second wiring pattern electrically connected to the electric terminal, which are facing each other through the dielectric layer, the second pattern facing portion facing the first pattern facing portion, in which when the dielectric layer is bent along a portion between the first pattern facing portion and the second pattern facing portion, at least one of the first ground conductor pattern and the second ground conductor pattern is located between the first wiring pattern and the second wiring pattern.

Optical module

Provided is a transmission system capable of improving the SN ratio for noise superimposed on a transmission line and extending the dynamic range. The transmission system transmits a signal between a transmitter () and a receiver (), which are connected to each other via a transmission line (). The transmitter () includes a transmission amplifier () for stepping up an amplitude of an input signal. The receiver () includes: an amplitude comparison circuit () for attenuating the amplitude of the signal, which is output from the transmission amplifier () and input via the transmission line (), and comparing the attenuated amplitude and a reference voltage; a variable attenuation circuit () for outputting, when the attenuated amplitude is larger than the reference voltage, the signal input to the receiver () after attenuating the amplitude of the signal, and for outputting, when the attenuated amplitude is smaller than the reference voltage, the signal input to the receiver () without attenuating the amplitude of the signal; and an amplitude limiting circuit () for clipping the amplitude of the signal output from the variable attenuation circuit () at a threshold voltage.

Growing community of inventors

Tokyo, Japan

Hideyuki Ohashi