Mitsubishi Electric Corporation

Mizuki Shirao

Keita Mochizuki

Nobuo Ohata

Yoshiya Sato

Kiyotomo Hasegawa

Hiroshi Aruga

Nobuyuki Yasui

Yuto Ueno

Fumio Shoda

Seiki Nakamura

Hayato Sano

Kei Masuyama

A high-frequency circuit is configured so as to include a printed circuit board and a flexible circuit board connected to the printed circuit board, wherein the printed circuit board includes: a first dielectric layer having a first surface and a second surface, a first ground conductor being formed on the first surface; a second dielectric layer having a third surface and a fourth surface, a second ground conductor being formed on the fourth surface; and first signal lines wired between the second surface and the third surface, the flexible circuit board includes: a third dielectric layer having a fifth surface and a sixth surface, a third ground conductor being formed on the fifth surface; a fourth dielectric layer having a seventh surface and an eighth surface, a fourth ground conductor being formed on the eighth surface; and second signal lines wired between the sixth surface and the seventh surface.

High-frequency circuit and communication module

A metal stem includes a cylindrical portion in which an FPC inserting portion is formed, and a base standing upright from one plane of the cylindrical portion. A tubular lens cap with one open end is fixed to a peripheral portion of the one plane of the cylindrical portion, and has a lens mounted on a bottomed portion. A substrate mounted on one plane of the base includes a signal wiring layer and a ground wiring layer. An optical semiconductor element is mounted on the substrate and has a signal terminal connected to the signal wiring layer of the substrate, and a ground terminal connected to the ground wiring layer of the substrate. An FPC substrate is disposed so as to pass through the FPC inserting portion and to face the one plane of the base. The FPC substrate includes a signal wiring layer connected to the signal wiring layer of the substrate with a metal wire.

Optical module

Included are a transmitter and a receiver caused to have a constant temperature. The transmitter includes: a semiconductor optical amplifier having a reflection mirror at a first end thereof; an optical waveguide having a first end coupled to a second end of the semiconductor optical amplifier; a wavelength demultiplexing filter having an input port coupled to a second end of the optical waveguide and a plurality of output ports having constant transmission wavelength intervals; reflection structures to reflect part of light output from the output ports, the reflection structures provided for the respective output ports of the wavelength demultiplexing filter; modulators to modulate light transmitted through the reflection structures, the modulators provided for the respective reflection structures; and a wavelength multiplexing filter having input ports coupled to the respective output ends of the modulators, transmission wavelength intervals of the input ports being identical to the transmission wavelength intervals of the wavelength demultiplexing filter, and having the output port coupled to a first end of an optical fiber. The receiver includes: a wavelength demultiplexing filter having an input port coupled to a second end of the optical fiber and a plurality of output ports having the same transmission wavelength intervals as the transmission wavelength intervals of the wavelength demultiplexing filter and an FSR obtained by multiplying the transmission wavelength interval by the number of the output ports; light receivers to receive light output from the output ports, the light receivers provided for the respective output ports of the wavelength demultiplexing filter; and a temperature controller to control the temperature of the wavelength demultiplexing filter.

Wavelength division multiplexing communication system and adjustment method of wavelength division multiplexing communication system

An optical module includes: a first lens and a second lens provided between a light emitter and a light receiver; and a base member on which the light emitter and the light receiver are placed, and each of the first lens and the second lens is fixed via an adhesive resin. A first bonding direction in which a first bonding surface of the first lens is bonded and fixed via an adhesive resin, and a second bonding direction in which a second bonding surface of the second lens is bonded and fixed via an adhesive resin are respectively perpendicular to an optical axis direction of light, and an orientation of the first bonding surface and an orientation of the second bonding surface make are different from each other.

An optical transmission apparatus () includes an optical transmitter () including an optical modulator () and an observation optical modulator () that attenuate optical power of input continuous wave light by an electro-absorption effect and output the continuous wave light. The optical modulator () performs pulse amplitude modulation on the continuous wave light and outputs the optical signal. The apparatus also includes: a bias voltage generation unit () that generates a direct-current bias voltage and outputs the direct-current bias voltage to the optical modulator () and the observation optical modulator (); a modulation signal generation unit () that generates an electrical signal for pulse amplitude modulation and outputs the electrical signal to the optical modulator (); and a bias voltage control unit () that instructs the bias voltage generation unit () to adjust the direct-current bias voltage on the basis of an absorption amount of optical power in the optical modulator () and an absorption amount of optical power in the observation optical modulator ().

Optical transmission apparatus, optical transmission method, control circuit of the optical transmission apparatus, and storage medium of the optical transmission apparatus

A terminal portion configured to obtain electrical connection with a printed circuit board includes a first signal pad that is formed in a first conductor layer and is electrically separated from a ground layer, a pair of first ground pads that is formed in the first conductor layer to sandwich the first signal pad and is connected to the ground layer, a second signal pad that is formed in a second conductor layer and is connected to a signal line, a pair of second ground pads that is formed in the second conductor layer to sandwich the second signal pad and is electrically separated from the signal line, a third signal pad formed in a third conductor layer, and a pair of third ground pads formed in the third conductor layer to sandwich the third signal pad. The second signal pad is wider than the third signal pad.

Flexible printed circuit board and circuit-board connection structure

An optical receiver is provided with a photoelectric converter that outputs an electrical signal according to light that is received by a light-receiving region. The optical receiver is provided with a condensing lens and optical filter that are located in an optical path from where signal light enters towards the light-receiving region. The condensing lens condenses the signal light onto the light-receiving region. The optical filter reflects light having a first wavelength that is included in the signal light using a front surface thereof and reflects light having a second wavelength that is included in the signal light using a rear surface thereof that faces the front surface so that the light is emitted through the front surface.

Growing community of inventors

Tokyo, Japan

Mizuki Shirao