摘要:
Disclosed is a micromirror for a hybrid optoelectronic integrated circuit, a method for manufacturing the same, a micromirror-photodetector assembly and an assembly of hybrid optoelectronic integrated circuit for receiving light. The micromirror the present invention comprises a silicon substrate and at least one V-shaped groove formed in the silicon substrate and the V-shaped groove has an inclined surface reflecting light emitted from an optical waveguide to a photodetector. The alignment of the photodetector and the optical fibers is achieved without an additional attachment equipment, by inserting the optical fibers into the V-groove.
摘要:
A method of forming a gate electrode of a compound semiconductor device includes forming a first insulating film pattern having a first aperture, forming a second insulating film pattern having a second aperture consisting of inverse V-type on the first insulating film pattern, forming a T-type gate electrode by depositing a conductivity film on the entire structure, removing a second insulating film pattern, forming a insulating spacer on a pole sidewall by etching a first insulating film pattern, and forming an ohmic electrode of the source and drain by self-aligning method using T-type gate electrode as a mask. Thereby T-type gate electrode of materials such as refractory metals can be prevented to be deteriorate because of high annealing, as well as it is stably formed, by using an insulating film. Ohmic metal and gate electrodes formed by self-aligning method can be prevented an interconnection by forming an insulating film spacer between these electrodes.
摘要:
The present invention relates to a bias stabilization circuit, specifically to a bias stabilization circuit for minimizing the current variations of amplification transistors caused by variations of device parameters which occur during the manufacturing of high-frequency integrated circuits using field-effect transistors, and caused by variations of supply voltage and temperature. In the present invention, the above problem is solved by configuring a level shifter circuit between the drain node and the gate node of the reference voltage generation transistor. Further, by using a constant current source utilizing a depletion transistor and series feedback resistors as a reference current, this circuit becomes stable against the variations of the device parameters as well as the variations of the temperature and supply voltage.
摘要:
The present invention relates to a gain control circuit for a low-noise amplifier. A gain control circuit of a 2-stage low-noise amplifier comprising an input stage noise matching circuit, an intermediate impedance matching circuit, a gain control circuit, and an output stage impedance matching circuit, said gain control circuit including: a feedback circuit connected to a transistor of second stage of the 2-stage low-noise amplifier, said feedback circuit detecting the amplified signal through the first stage and the second stage, and feeding the signal back through a switch circuit; and an attenuation circuit for compensating the harmonics of the input signal.
摘要:
The present invention relates to an equivalent circuit of a package ground terminal paddle which is used to mount a microwave integrated circuit, and more particularly, to an approximate equivalent circuit of the package ground terminal paddle by which the expressions of parasitic components can be easily expanded according to the number of gold wires that are down-bonded to the paddle, by introducing an equivalent circuit structure which takes the impedance component output from each terminal as one common impedance component and grounds the common impedance.
摘要:
The present invention relates to a gain controlled amplifier, and more particularly, to a gain controlled amplifier using active feedback and variable resistance. It is an object of the present invention to provide a gain controlled amplifier minimizing the gain and the degradation of power characteristics generated when adjusting gain in a variable gain amplifier which receives signals having different power levels, amplifies them in accordance with each power level and outputs output signals in a constant power level. In order to achieve the above object, a gain controlled amplifier in accordance with the present invention comprises an amplifier and an active feedback means for negative feedbacking the output of the amplifier to the input of the amplifier, and further has a feedback amount controller inputting the controlled feedback signal to the amplifier by controlling the feedback amount of said active feedback means.
摘要:
A method for correcting a high frequency measurement error which can exactly correct the high frequency measurement error even with the use of a standard devices of which characteristic have not been verified by calculating the characteristic impedance of the correction device from the characteristics of an auxiliary measuring device calculated by using a general error correction method, and calculating again the once calculated characteristics of the auxiliary measuring device. The method in accordance with the present invention comprises the steps of modelling an auxiliary measuring device used for measuring a high frequency charateristics of the device under test by two transmission lines connected in series between two terminals and a parasitic component connected in parallel between a junction of the two transmission lines and a ground; and moving a reference measurement point to the junction of the two transmission lines by using a phase angle of each transmission line and calculating a reference impedance at the terminal of the auxiliary measuring device to which an object to be measured is connected by using the difference of the resultant reflection coefficients of each port.
摘要:
There is disclosed a photodetector having two or more avalanche-gain layered structures and multi-terminals. The avalanche photodetector includes an emitter light absorption layer structure located between a collector layer and an emitter layer (top contact layer) stacked on a substrate. The photodetector further comprises multiple avalanche-gain layered structures consisting of a charge layer, a multiplication layer and a contact layer between the light absorption layer and said collector layer.
摘要:
The present invention relates to an electrical field absorbing semiconductor optical modulator, more particularly, to a high speed semiconductor optical modulator and a fabricating method thereof. The present invention includes a high speed semiconductor optical modulator, the optical modulator formed by stacking an n-type light-wave guiding layer, a light absorbing layer, a p-type light-wave guiding layer, a p-type clad layer, and a p-type ohmic contact layer on a substrate successively, the optical modulator having a ridge structure wherein the optical modulator is an electric-field absorbing type, and wherein width W3 of the light absorbing layer is less than the width W1 of the p-type ohmic contact layer. Accordingly, the present invention enables to provide high speed optical modulation of tens of giga rate of which modulating characteristics are excellent by reducing contact resistance and capacitance, which are the major problems of ruining the characteristics of an optical modulator, simultaneously.
摘要:
Disclosed is a method for manufacturing a vertical channel transistor comprising the steps of: selectively implanting a dopant of high concentration into a semiconductor substrate to form a source region; firstly etching the semiconductor substrate using an insulator and a first photoresist pattern as a mask; secondly etching the substrate using a second photoresist pattern having a shape corresponding to said source region as a mask; implanting a dopant of low concentration into the exposed substrate using said second photoresist pattern as a mask to form a vertical channel layer; implanting a dopant of high concentration into the exposed substrate using same mask to form a drain region; activating said dopants, and forming an ohmic contact layer on said drain region; thirdly etching using a third photoresist pattern for exposing the firstly etched portion of the substrate as a mask; depositing a gate metal on the substrate exposed by the thirdly etching; and wiring a metal, respectively. This invention can be easily manufactured a vertical channel transistor having a low parasitic resistance and an extremely small gate length without sophicated complex processes.