Electronics and Telecommunications Research Institute

Korea Telecom

Seong-Su Park

Min-Kyu Song

Jeen Hur

Hoo-Sung Lee

Dong-Goo Kim

Seung-Goo Kang

Byoung Gun Choi

Hyung-Moo Park

Seok-bong Hyun

Nam Hwang

Byung-Jo Kim

Hyung-Jin Yoon

Hee-Tae Lee

Sung-Rae Cho

Geum-Young Tak

Young-Ho Kim

Kyung Hwan Park

Seok Bong Hyun

Chul Soon Park

Byung Jo Kim

Kyu-Ha Baek

Hee Tae Lee

Kyung-Hwan Park

Sun-hee Kim

Sang-Hwan Lee

Jong-Tae Moon

June-Young Chang

Tae-Young Kang

Seok-Bong Hyun

Sangbaek Han

Geum Young Tak

A wide viewing angle holographic image display method and apparatus are disclosed. The wide viewing angle holographic image display apparatus includes a scan line unit and a control unit. The scan line unit includes a plurality of lateral scan lines that represent different angles, respectively. The control unit performs control so that different data are output at the respective different angles, represented by the lateral scan lines, using the plurality of lateral scan lines.

Wide viewing angle holographic image display method and apparatus

Provided is a method for controlling a low-power state in a mobile handset. The method includes shifting from an active state to a low-power idle state by blocking power of modules for a mobile communication function and decreasing a frequency of a control clock when an inactive request of the mobile communication function is received; shifting from the low-power idle state to a low-power access state by increasing the frequency of the control clock when an additional service request is received; shifting from the low-power access state to the low-power idle state if an additional service request is not received any more; shifting from the low-power idle state to a suspension state by suspending the control clock when request is not received for predetermined time; and shifting from the suspension state to the low-power idle state when the input interrupt and the timer interrupt occur.

Method for controlling low-power state in mobile handset

there is provided a spreading apparatus using a child orthogonal variable spreading factor (OVSF) code pair, including: a channel condition information receiving unit for receiving channel condition information including a channel condition metric; a switch controlling unit for receiving the channel condition information from the channel condition information receiving unit and transferring data stream according to the received channel station information; a first spreading unit for receiving the data stream from the switching controlling unit, and spreading the data stream using a single OVSF code; and a second spreading unit for receiving the data stream from the switching controlling unit, and spreading the data stream using a child OVSF code pair.

Apparatus and method for spreading/de-spreading data using pair of child orthogonal variable spreading factor codes

Provided is a driving voltage control module capable of minimizing current consumption and time taken to return from a standby state to a normal state by controlling driving voltages for electronic circuits and systems for communication when a mobile communication transceiving circuit or a communication system is in a standby state in which there is no busy signal. The driving voltage control module includes a regulator for converting an input power voltage into a predetermined level of DC voltage, and supplying the converted DC voltage to an external circuit module as a driving voltage; and a voltage controller for controlling an output voltage level of the regulator, wherein, under control of the voltage controller, a level of the driving voltage is adjusted to be a standby voltage level lower than a turn-on voltage level of a switching device constituting the external circuit module. With the driving voltage control module, the transceiving circuit and the RF circuit of the RF mobile communication terminal can be supplied with distinct power voltages each corresponding to the cut-off state, the standby state, and the normal operation state, thereby reducing current consumption and the time taken to reach the normal state from the standby state. This can increase the battery lifetime and embody a high-speed RF mobile communication terminal.

Driving voltage control module

The present invention provides an efficient data transmission method in BLUETOOTH broadcasting. The method of BLUETOOTH broadcasting generates a first broadcast packet and determines whether a slot is included in an access window. In a case where the slot is not included in the access window, a service interface (SI) information value is set to the assignment information of the slot. The first broadcast packet is then transmitted. A second broadcast packet is then generated and it is determined whether a slot is included in the access window. If the slot is not included in the access window, the SI information value is set to zero. The second broadcast packet is then transmitted. A slave receives the broadcast packets and obtains the SI information values. It is then determined whether the slave transmits data at the next odd numbered slot.

Bluetooth broadcasting method

Provided is a direct-conversion frequency mixer for down converting a radio frequency (RF) signal into a baseband signal, in which a single phase RF signal and a quadrature location oscillation (quadrature LO) signal are used to generate the baseband signal, the frequency mixer comprising a first frequency mixing unit that uses quadrature LO signals having respective phases of 0 degrees and 180 degrees to directly down-convert the single phase RF signal into the in-phase baseband signal, and a second frequency mixing unit that uses quadrature LO signals having respective phases of 90 degrees and 270 degrees to directly down-convert the single phase RF signal into the quadrature-phase baseband signal, whereby drains and sources of the transistor for receiving the quadrature LO signal and the transistor for receiving the RF signal are connected in common, thus enabling low power source voltage driving.

Direct-conversion frequency mixer

Provided are a pulse signal generator for UWB radio transception and a radio transceiver having the same. The pulse signal generator includes: an envelope generator generating a plurality of envelope signals; a local oscillator array composed of a plurality of high frequency oscillators, each outputting two oscillation signals having a phase difference from each other; a multiplier array receiving the envelope signals and the oscillation signals and outputting signals obtained by respectively multiplying the envelope signals by the oscillation signals; and an I channel adder and a Q channel adder outputting an I channel pulse signal and a Q channel pulse signal by adding output signals having the same phase components among the signals output from the multiplier array, respectively.

Pulse signal generator for ultra-wideband radio transception and radio transceiver having the same

Provided is a linearization apparatus of a triode region type operational transconductance amplifier that can provide a wide linear input range even when a differential pair input transistor having a short channel length is used at a low power supply voltage. The linearization apparatus of the triode region type operational transconductance amplifier includes: a first transconductor unit for receiving differential pair input voltages through differential pair input transistors and generating a basic transconductance; and a second transconductor unit for receiving the same differential pair input voltages, generating distortion transconductances, and overlapping the basic transconductace with the distortion transconductance for extending a linear range of a final transconductance.

Linearization apparatus of triode region type operational transconductance amplifier

Provided is a phase frequency detector for use in a phase locked loop (PLL) or a delay locked loop (DLL), the phase frequency detector including: an UP signal output unit having a first stage operated according to a reference clock delayed by a predetermined time and a reset signal, a second stage operated according to the reference clock and an output of the first stage, and an inverter for inverting an output of the second stage; a DOWN signal output unit having: a first stage operated according to an outer clock delayed by a predetermined time and the reset signal, a second stage operated according to the outer clock and an output of the first stage, and an inverter for inverting an output of the second stage; and a logic gate logically combining the output of the second stage of the UP signal output unit and the output of the second stage of the DOWN signal output unit to generate the reset signal, thereby a phase range of the input signal with which an effective control signal can be obtained is wide so that low power consumption and low noise characteristics can be obtained due to fast phase lock, low power consumption of a dynamic logic, and fast signal transmission.

Phase frequency detector

In the adaptive wireless network system having a central optimizer and a method thereof, and in the record medium capable of being read through a computer having a writing of a program to realize the inventive method, in which information for a use wave environment of a corresponding subnet is gained from an access point regardless of a sort of wireless communication instruments so as to apply an optimum transmission/reception type of the corresponding subnet thereto; the system includes an optimizing unit for selecting optimum transmission/reception types of sub networks and transmitting them; an access point determining unit for providing node activity representative data and activity representative data of access point itself, to the optimizing unit, and determining it as the optimum transmission/reception type; and a communication node determining unit for re-determining its own transmission/reception type according to a requirement of the access point determining unit.

Adaptive wireless network system comprising central optimizer and method thereof

An improved optical module having lenses aligned on a lens-positioning V-groove and a fabrication method thereof which includes a silicon substrate, which defines a light transfer path below a surface thereof, including light transferring V-grooves and a light receiving V-groove, and lens-positioning V-groove for determining the position of a lens, wherein two lens-positioning V-grooves are formed therein, an optical transmitter module including a laser which is a light source and is flip-chip-bonded to the substrate by a solder bump after an optical waveguide is previously aligned with the V-groove by using an alignment mark behind the vertical portion of the light transferring v-groove. A light transferring lens attached on one lens-positioning V-groove for condensing the light from the laser, and a laser monitoring optical detector arranged on a side wall opposite the laser of the light transferring V-groove, wherein an active region is flip-chip-bonded toward the substrate, for monitoring the laser, and an optical receiver module including a light receiving lens attached on the lens-positioning V-groove of the silicon substrate for condensing beam externally transferred thereto, and a light receiving optical detector attached to the light receiving lens for detecting beam externally transferred thereto, wherein the optical transmitter module and the optical receiver module are arranged in the same silicon substrate.

Optical module having lenses aligned on lens-positioning V-groove and

The present invention relates to an accurate method using laser welding for mounting an optical focusing lens utilized in a semi-conductor laser module for optical transmission and optical amplification through an optical fiber and a laser module so produced. The laser module includes an aligned laser diode, a lens fixture mounting the laser diode, a focusing lens mounted within a lens housing which in turn is mounted by a lens ring to the lens fixture. In the method, the steps include aligning mutual positions between the laser diode and the optical focusing lens in the vertical and horizontal directions so that the magnitude of the optical signal output from the optical fiber is maximized after the distance between the optical focusing lens and the optical fiber is adjusted and fixed to obtain a maximum optical coupling efficiency between the laser diode and the optical fiber. Next a laser-welding step is performed at an interval between the lens housing and the lens ring. The mutual positions between the laser diode and the optical focusing lens are aligned in the vertical and horizontal directions so that the magnitude of the optical signal output from the optical fiber is maximized. Finally a laser-welding step is performed at an interval between the lens fixture and the lens ring.

Laser module with focusing lens and fixing method of the focusing lens

A package for a power semiconductor device is made using the method comprising the steps of preparing a lead frame including a blade or paddle for providing a semiconductor chip on a top surface thereof, tie bars for supporting said paddle, wherein said paddle being provided lower in horizontal surface than the leads; attaching a heat radiating plate on a bottom surface of the paddle by cladding; attaching a Kovar plate on the top surface of the paddle by soldering, said Kovar plate having similar heat expansion coefficient to that of the chip; providing the chip on the Kovar plate by soldering; wire-bonding terminals of said semiconductor chip to the corresponding leads of the lead frame, respectively; coating polyimide over the semiconductor chip by spin-coating; curing the polyimide coated thus; forming a metal cap above the said paddle by soldering, and injecting a molding material into a molder for enclosing the paddle and curing the molding material injected thus. The method can be applied to produce a plastic package of a power semiconductor device at low cost. The metal cap is grounded through the tie bars as a source electrode to shield a noise.

Package for a power semiconductor device

A method of packaging a power semiconductor device is disclosed, comprising the steps of preparing a lead frame including a paddle for providing a semiconductor chip on a top surface thereof, tie bars for supporting said paddle, wherein said paddle being provided lower in horizontal surface than the leads; attaching a heat radiating plate on a bottom surface of the paddle by cladding; attaching a Kovar plate on the top surface of the paddle by soldering, said Kovar plate having similar heat expansion coefficient to that of the chip; providing the chip on the Kovar plate by soldering; wire-bonding terminals of said semiconductor chip to the corresponding leads of the lead frame, respectively; coating polyimide over the semiconductor chip by spin-coating; curing the polyimide coated thus; forming a metal cap above the said paddle by soldering, and injecting a molding material into a molder for enclosing the paddle and curing the molding material injected thus the method can be applied to produce a plastic package of a power semiconductor device at low cost. The metal cap is grounded through the tie bars as a source electrode to shield a noise.

Growing community of inventors

Daejeon, South Korea

Seong-Su Park