Abstract:
Provided are a phase shifter with a photonic band gap (PBG) structure using a ferroelectric thin film. The phase shifter includes a microstrip transmission line acting as a microwave input/output line and a plurality of tunable capacitors arranged in the microstrip transmission line at regular intervals. Electrodes disposed on a substrate apply DC voltages to the plurality of tunable capacitors. Radio frequency (RF) chokes and quarter wavelength radial-stubs are connected between the electrodes and the microstrip transmission line in order to prevent high frequency signals from flowing into a DC bias terminal. A plurality of PBGS are periodically arrayed on a ground plane of the substrate.
Abstract:
Provided are a temperature sensor using a metal-insulator transition (MIT) device subject to abrupt MIT at a specific temperature and an alarm including the temperature sensor. The abrupt MIT device includes an abrupt MIT thin film and at least two electrode thin films that contacts the abrupt MIT thin film. The abrupt MIT device generates abrupt metal-insulator transition at a specific transition temperature. The alarm includes a temperature sensor comprising an abrupt MIT device, and an alarm signaling device serially connected to the temperature sensor. Accordingly, the alarm can be manufactured to have a simple circuit and be of a small size by including the temperature sensor using an abrupt MIT device.
Abstract:
Provided is a field emission display (FED) capable of driving on the basis of current and preventing leakage current caused by thin film transistors (TFTs). The FED includes: a plurality of unit pixels including an emission element in which cathode luminescence of a phosphor occurs and a TFT for driving the emission element; a current source for applying a scan signal to each unit pixel; and a voltage source for applying a data signal to each unit pixel. Here, the on-current of the current source is high enough to take care of the load resistance and capacitance of a scan row within a given writing time, and the off-current of the current source is so low that the electron emission of each pixel can be ignored. In addition, the pulse amplitude or pulse width of the data signal applied from the voltage source is changed, and thereby the gray scale of the display is represented.
Abstract:
Provided are an abrupt metal-insulator transition (MIT) device for bypassing super-high voltage noise to protect an electric and/or electronic system, such as, a high-voltage switch, from a super-high voltage, a high-voltage noise removing circuit for bypassing the super-high voltage noise using the abrupt MIT device, and an electric and/or electronic system including the high-voltage noise removing circuit. The abrupt MIT device includes a substrate, a first abrupt MIT structure, and a second abrupt MIT structure. The first and second abrupt MIT structures are formed on an upper surface and a lower surface, respectively, of the substrate. The high-voltage noise removing circuit includes an abrupt MIT device chain connected in parallel to the electric and/or electronic system to be protected. The abrupt MIT device chain includes at least two abrupt MIT devices serially connected to each other.
Abstract:
A current-jump-control circuit including an abrupt metal-insulator phase transition device is proposed, and includes a source, the abrupt metal-insulator phase transition device and a resistive element. The abrupt metal-insulator phase transition device includes first and second electrodes connected to the source, and shows an abrupt metal-insulator phase transition characteristic of a current jump when an electric field is applied between the first electrode and the second electrode. The resistive element is connected between the source and the abrupt metal-insulator phase transition device to control a jump current flowing through the abrupt metal-insulator phase transition device. According to the above current control circuit, the abrupt metal-insulator phase transition device can be prevented from being failed due to a large amount of current and thus the current-jump-control circuit can be applied in various application fields.
Abstract:
A terahertz continuous wave generator includes: an optical intensity modulator configured to modulate an optical signal into DSB optical signals; a local oscillator configured to generate a modulation signal for modulating the optical signal inputted to the optical intensity modulator into DSB optical signals; a notch filter configured to filter an optical signal with a specific frequency; an optical fiber amplifier configured to amplify an output signal of the optical intensity modulator; an optical circulator configured to transmit the optical signal inputted to the optical fiber amplifier to the notch filter and transmit the optical signal reflected from the notch filter to an input of the optical intensity modulator; an optical coupler configured to apply the optical signal to the optical intensity modulator; and an OE converter configured to photomix the DSB signals outputted through the notch filter.
Abstract:
A field emission pixel includes a cathode on which a field emitter emitting electrons is formed, an anode on which a phosphor absorbing electrons from the field emitter is formed, and a thin film transistor (TFT) having a source connected to a current source in response to a scan signal, a gate receiving a data signal, and a drain connected to the field emitter. The field emitter is made of carbon material such as diamond, diamond like carbon, carbon nanotube or carbon nanofiber. The cathode may include multiple field emitters, and the TFT may include multiple transistors having gates to which the same signal is applied, sources to which the same signal is applied, and drains respectively connected to the field emitters. An active layer of the TFT is made of a semiconductor film such as amorphous silicon, micro-crystalline silicon, polycrystalline silicon, wide-band gap material like ZnO, or an organic semiconductor.
Abstract:
A switching field effect transistor includes a substrate; a Mott-Brinkman-Rice insulator formed on the substrate, the Mott-Brinkman-Rice insulator undergoing abrupt metal-insulator transition when holes added therein; a dielectric layer formed on the Mott-Brinkman-Rice insulator, the dielectric layer adding holes into the Mott-Brinkman-Rice insulator when a predetermined voltage is applied thereto; a gate electrode formed on the dielectric layer, the gate electrode applying the predetermined voltage to the dielectric layer; a source electrode formed to be electrically connected to a first portion of the Mott-Brinkman-Rice insulator; and a drain electrode formed to be electrically connected to a second portion of the Mott-Brinkman-Rice insulator.
Abstract:
Provided is an optical disk drive adapter comprising: a first rotating portion disposed at the center of an optical disk drive and installing a turntable on which a standard optical disk is mounted; a second rotating portion disposed beside the first rotating portion and installing a turntable on which a subminiature optical disk is mounted; a force transmitting portion disposed between the first rotating portion and the second rotating portion and transmitting a rotary force between the first rotating portion and the second rotating portion; and a housing supporting the entire optical disk drive adapter so that the first rotating portion, the second rotating portion, and the force transmitting portions can be rotated on their axes while maintaining their overall shape. Accordingly, without an additional subminiature optical disk drive, a subminiature optical disk can be driven using a conventional standard optical disk drive.
Abstract:
There is provided a packaging apparatus of a terahertz device, the apparatus including: a terahertz device having an active region at which terahertz wave is radiated or detected; a device substrate mounting the terahertz device whose active region is positioned at an opening region formed at the center of the device substrate, and electrically connecting the terahertz device and an external terminal to each other; a ball lens block arranged and fixed to an upper part of the terahertz device; and upper and lower cases receiving the device substrate mounted with the terahertz device therein and opening region vertical upper and lower portions of the active region of the terahertz device.