Soonchunhyang University Industry Academy Cooperation Foundation

Dal Ahn

Sang-Min Han

Jong-Sik Lim

Jongsik Lim

Young-Sik Kim

Sung-Min Kim

Won-Sang Yoon

Tae-Hoon Kang

You-Na Jang

Ji-Won Kim

Dae-Ung Lee

Ik-Soo Jang

Jun-Seok Oh

Kwan-Sun Choi

Seo Koo

Jong Im Park

The present invention relates to a Doherty combiner used in a Doherty power amplifier, the Doherty combiner comprising: a phase shift section connected to one end of a carrier amplifier so as to change a phase of an RF signal output from the carrier amplifier; a matching section connected to an output terminal of the Doherty power amplifier so as to impedance-match an output of the Doherty power amplifier; and a bandwidth improvement section connected to one end of a peaking amplifier so as to change at least one of a phase bandwidth and an amplitude bandwidth of the Doherty power amplifier.

Doherty combiner

Disclosed are a microstrip transmission line having a common defected ground structure (DGS) and a wireless circuit apparatus having the same. The microstrip transmission line realizes a common defected ground structure (DGS) and a double microstrip structure, and includes: a first dielectric layer; a first signal line pattern formed on a first surface of the first dielectric layer; a common ground conductive layer formed on a second surface of the first dielectric layer and having a defected ground structure, the first surface facing the second surface; a second dielectric layer having a first surface brought into contact with the common ground conductive layer, and facing the first dielectric layer while interposing the common ground conductive layer between the first dielectric layer and the second dielectric layer; and a second signal line pattern formed on a second surface of the second dielectric layer, the first surface facing the second surface.

Double microstrip transmission line having common defected ground structure and wireless circuit apparatus using the same

In an ultra-wideband (UWB) band-pass filter, an equivalent circuit of a band-pass filter for direct frequency conversion is configured to have a series LC resonator and a parallel LC resonator, the parallel LC resonator is implemented as a short stub and an open stub, and the series LC resonator is implemented by modeling an inductor and a capacitor as a distributed constant circuit. The series LC resonator is implemented to have a 3D structure for effective designing of the band-pass filter by a new method of implementing a series resonator circuit. In the UWB band-pass filter, a low-pass filter for improving band-stop characteristics is additionally connected.

Serial L-C resonator with three-dimensional structure and ultra-wide bandpass filter using the same

A system for performing a local wireless communication using a predetermined frequency band divided into a plurality of channels. The system includes a hub for scanning each channel to identify available one of the plurality of channels and transmitting data over the available channel. The system further includes a sensor set to start to operate when the sensor detects a signal within the predetermined frequency band. The sensor spectrum-senses the signal of the frequency band for each channel, and analyzes a header of packet data for each channel, and receives and processes the packet data if the signal is identified to have a designated code.

Local wireless communication system and method employing frequency-variable signal detection

Disclosed herein is a dual band high frequency amplifier using a composite right/left handed (CRLH) transmission line (TL). Accordingly, a CRLH TL structure having a dual band characteristic is inserted into an input matching circuit and/or an output matching circuit in the high frequency amplifier, and a matching circuit is designed so that impedance matching is performed at two frequencies, thereby obtaining both gain and matching characteristics at the two frequencies.

Dual band high frequency amplifier using composite right/left handed transmission line

Growing community of inventors

Chungcheongnam-do, South Korea

Dal Ahn