Abstract:
Provided is a high-speed optical interconnection device. The high-speed optical interconnection device includes a first semiconductor chip, light emitters, optical detectors, and a second semiconductor chip, which are disposed on a silicon-on-insulator (SOI) substrate. The light emitters receive electrical signals from the first semiconductor chip to output optical signals. The optical detectors detect the optical signals to convert the optical signals into electrical signals. The second semiconductor chip receives the electrical signals converted by the optical detectors.
Abstract:
Provided are an optoelectronic (OE) transmitter integrated circuit (IC) and method of fabricating the same using a selective growth process. In the OE transmitter IC, a driving circuit, which includes a double heterojunction bipolar transistor (DHBT) and amplifies received electric signals to drive an electroabsorption (EA) modulator, and the EA modulator with a multi-quantum well (MQW) absorption layer are integrated as a single chip on a semi-insulating substrate. The MQW absorption layer of the EA modulator and an MQW insertion layer of the DHBT are formed to different thicknesses from each other using a selective MOCVD growth process.
Abstract:
There is provided a millimeter wave band frequency optical oscillator predicted to be used as a millimeter wave oscillating frequency signal source in a base station of a millimeter wave wireless transmission system. The optical oscillator has a double resonator structure in which a pair of wavelength tunable fiber grating mirrors are inserted into a unilateral fiber-ring laser resonator in order to internally and additionally form a linear laser resonator. The double resonator structure composed of the two stable laser resonators can oscillate laser of two modes. Due to a beat phenomenon occurring between the two modes, received laser is modulated to an ultra-speed frequency of 60 GHz or greater. A variation in the gain within a resonator is induced by a polarization controller using the dependency of laser modes upon polarization. A modulation frequency is consecutively changed from 60 GHz to 80 GHz by controlling the wavelength of light reflected by the fiber grating mirrors.
Abstract:
Provided are vertical capacitors and methods of forming the same. The formation of the vertical capacitor may include forming input and output electrodes on a top surface of a substrate, etching a bottom surface of the substrate to form via electrodes, and then, forming a dielectric layer between the via electrodes. As a result, a vertical capacitor with high capacitance can be provided in a small region of the substrate.
Abstract:
Disclosed are a power semiconductor device and a method of fabricating the same which can increase a breakdown voltage of the device through a field plate formed between a gate electrode and a drain electrode and achieve an easier manufacturing process at the same time. The power semiconductor device according to an exemplary embodiment of the present disclosure includes a source electrode and a drain electrode formed on a substrate; a dielectric layer formed between the source electrode and the drain electrode to have a lower height than heights of the two electrodes and including an etched part exposing the substrate; a gate electrode formed on the etched part; a field plate formed on the dielectric layer between the gate electrode and the drain electrode; and a metal configured to connect the field plate and the source electrode.
Abstract:
Provided is a polarization division multiplexed optical OFDM transmitter. The polarization division multiplexed optical OFDM transmitter includes a data demultiplexer, a training symbol generation unit and an optical up-converter and polarization division multiplexing unit. The data demultiplexer divides a transmission signal into a plurality of groups. The training symbol generation unit allocates a plurality of training symbols for each OFDM data which is included in the respective multiplexed groups, and allocates repetitive data in a time domain for the respective training symbols for data of 0 to periodically appear for the respective training symbols in a frequency domain. The optical up-converter and polarization division multiplexing unit performs optical frequency band conversion and polarization division multiplexing on an output of the training symbol generation unit to output a polarization division multiplexed optical OFDM signal corresponding to a plurality of polarization components.
Abstract:
Provided is an optical OFDM receiver. The optical OFDM receiver receives an optical signal dependent on the nonlinearity of a transmitter. The optical OFDM receives includes an optical down converter, a nonlinearity compensator, and an OFDM demodulator. The optical down converter converts the optical signal into an electrical signal. The nonlinearity compensator filters the electrical signal, for compensating distortion which is added to the optical signal when the transmitter performs optical modulation. The OFDM demodulator demodulates the distortion-compensated electrical signal in an OFDM scheme.
Abstract:
Provided is a feedback amplifier including: an amplification circuit unit to generate an output voltage by amplifying an input voltage inputted through an input terminal; an output circuit unit to output the generated output voltage through an output terminal; a feedback circuit unit to control the gain of the amplification circuit unit by determining a total feedback resistance value using an external control signal and controlling an input current while the total feedback resistance value is determined; and a bias circuit unit to apply a bias voltage to the feedback circuit unit.
Abstract:
A method for fabricating a field effect transistor according to an exemplary embodiment of the present disclosure includes: forming an active layer, a cap layer, an ohmic metal layer and an insulating layer on a substrate; forming multilayered photoresists on the insulating layer; patterning the multilayered photoresists to form a photoresist pattern including a first opening for gate electrode and a second opening for field electrode; etching the insulating layer by using the photoresist pattern as an etching mask so that the insulating layer in the first opening is etched more deeply and the cap layer is exposed through the first opening; etching the cap layer exposed by etching the insulating layer through the first opening to form a gate recess region; and depositing a metal on the gate recess region and the etched insulating layer to form a gate-field electrode layer.
Abstract:
A semiconductor package is provided. The semiconductor package includes a package body, a plurality of semiconductor chips, and an external connection terminal. The package body is stacked with a plurality of sheets where conductive patterns and vias are disposed. The plurality of semiconductor chips are inserted into insert slots extending from one surface of the package body. The external connection terminal is provided on other surface opposite to the one surface of the package body. Here, the plurality of semiconductor chips are electrically connected to the external connection terminal.