Abstract:
PURPOSE: A method for integrating an active optical device and a passive optical device, and an integrated device thereby are provided to form the active optical device and the passive optical device on one substrate by changing a buried ridge waveguide into a strip loaded waveguide. CONSTITUTION: A taper is formed at an end of a passive waveguide connected to a buried ridge waveguide of an active device in order to change the taper into the strip loaded taper when a center of the buried ridge waveguide of the active device is etched. The taper is covered by a re-growth process. The taper is arranged to the taper formed at an end of the buried ridge waveguide. The strip-loaded waveguide is formed by performing an etching process. An etch-stop layer is inserted in the process for growing the passive waveguide layer in order to form constantly the etching depth.
Abstract:
PURPOSE: A method for manufacturing an optical integrated circuit is provided to automatically align two optical devices with each other by defining a waveguide of a passive device and an active device by using only one mask. CONSTITUTION: A method for manufacturing an optical integrated circuit includes the steps of: forming a core layer(101) and a buffer layer(102) of a mode size converter on a substrate(100) provided with an active region(A) and a passive region(B); forming a first guide layer, the core layer(101), a second guide layer and a clad layer on the buffer layer(102) of the active region(A); forming the core layer(101) and the clad layer on the buffer layer(102) of the passive region(B); forming a first mask pattern so as to define the width of the upper waveguide of the mode size converter; etching the clad layer, the second guide layer, the core layer(101) of the active region(A), the first guide layer and the buffer layer(102) of the passive region(B) by using the first mask; after forming the second mask, removing the buffer layer(102), the core layer(101) and the portion of the substrate; forming a current blocking layer on the exposed substrate; and forming the clad layer on the entire top surface by removing the second mask pattern of the active region(A).
Abstract:
PURPOSE: An integrated inductor is provided to reduce a substrate loss according to a magnetic field which directs to a substrate and restrain a generation of a counter electromotive force due to an interference between adjacent metal lines. CONSTITUTION: A metal line includes the first spiral line(21) and the second spiral line(22). The second spiral line(22) is connected to the first spiral line(21) through a contact point(21a). The first spiral line(21) and the second spiral line(22) are arranged in various shapes such as a square, a circle, and a hexagon. The metal line uses a metal film which is laminated by a single layer or a multiple layer. A protective film(32) is formed on the metal line. The first interlayer dielectric(31) is formed on a silicon substrate(30). A metal film is deposited on the first interlayer dielectric(31), and is selectively etched to form the metal line having the first and second spiral lines(21,22).
Abstract:
Disclosed is an operational transconductance amplifier (OTA) for an ultra-wideband (UWB) filter which is a core block enabling processing of UWB signals among RF blocks constituting a coherent UWB receiver corresponding with IEEE 802.15.4a UWB standards. A Nauta-operational transconductance amplifier for the UWB filter in a UWB based indoor positioning system, according to the present invention comprises: two first g_m cells which receive an input positive voltage and an input negative voltage, respectively; and two second g_m cells, each of which has an input terminal connected to an output terminal of any one among the first g_m cells and an output terminal connected to an output terminal of the other among the first g_m cells. The Nauta-operational transconductance amplifier for the UWB filter outputs a first output current and a second output current having a current difference proportional to a voltage difference between the input positive voltage and the input negative voltage.