• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.7
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• pp.18-22
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• 2010

In this paper, we propose and analyze the two way ranging (TWR) positioning technique using ultra wideband (UWB) for indoor environment. We employed IEEE 802.15.3a channel as a simulation environment and used to time of arrival (TOA) algorithm. UWB technology in a low transmission power the less the effect of interfering with the existing system, the frequency can be shared so that it can improve the spectral efficiency. And, positioning technique based on UWB with a very narrow pulse width has high accuracy in indoor environment. From the simulation results, it is analyzed the probability of error and positioning performance for channel effects and confirmed usefulness of the proposed scheme.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.3 s.94
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• pp.235-245
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• 2005

In this paper, a novel Ultra-Wideband(UWB) antenna fed by CPW is designed, fabricated, and measured for UWB communications. We have used the Microwave Studio of CST to simulate the proposed antenna. It is designed to work on a substrate TMM4 of thickness 0.762 mm and relative permittivity 4.5. The proposed antenna is satisfied with Ultra-Wideband communication band from 3.1 GHz to 11.5 GHz, for VSWR$\leq$2, and isolated IEEE 802.1la frequency band(5.15 GHz$\~$5.825 GHz) using a rectangular slot. Measured group delay variation is less than 1 ns, thus indicating the proposed antenna a good candidate for UWB applications.

• Journal of Advanced Navigation Technology
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• v.14 no.5
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• pp.745-751
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• 2010

In this paper, the proposed a narrowband interference cancellation techniques for the frequence sharing of Ultra wideband Impulse Radio communication system and narrowband communication system. In this system, the narrowband communication signals can cause intolerant interferences to Impulse Radio signals. In this paper, Ultra wideband Impulse Radio system have been analyzed in AWGN, MAI and NI(Narrowband Interference) environment. Also, performance improvement has been obtained by adopting an adaptive notch filtering scheme using Complex Filter Bank and CCI canceller. The results show that there is a substantial enhancement in performance by employing the adaptive notch filtering and/or CCI canceller.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.7C
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• pp.475-480
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• 2011

Ultra-wideband (UWB) signal energy spreads over multiple correlator outputs due to rich multipaths, making the output of each correlator have only a small portion of the total energy. Thus, in the proposed two-stage UWB signal detection scheme for cognitive radio communication systems, the decision variable is formed by combining multiple correlator outputs, making it possible to collect the signal energy spread by the multipaths, Simulation results show that the proposed scheme can provide a gain of about 0.6 dB over the conventional schemes in various UWB channel environments.

• ETRI Journal
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• v.41 no.6
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• pp.715-730
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• 2019

We propose a switched beam-forming antenna that satisfies not only ultra-wideband characteristics but also beam-forming in the WLAN frequency band using an ultra-wideband antenna and passive parasitic elements applying a broadband optimal reactance load algorithm. We design a power and phase estimation function and an error correction function by re-analyzing and normalizing all the components of the parasitic array using control system engineering. The proposed antenna is compared with an antenna with a pin diode and reactance load value, respectively. The pin diode is located between the passive parasitic elements and ground plane. An antenna beam can be formed in eight directions according to the pin diode ON (reflector)/OFF (director) state. The antenna with a reactance load value achieves a better VSWR and gain than the antenna with a pin diode. We confirm that a beam is formed in eight directions owing to the RF switch operation, and the measured peak gain is 7 dBi at 2.45 GHz and 10 dBi at 5.8 GHz.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.11
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• pp.36-40
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• 2013

A novel design method of ultra wideband bandpass filter using CRLH transmission line with Dumbell type DGS is presented in this paper. Defected Ground Structure and microstrip interdigital capacitor are used to design the ultra wideband (UWB) filter. CRLH transmission line has composite characteristics of low pass and high pass filter. As control of cutoff frequency of low pass and high pass response on CRLH transmission line, we can get characteristic of UWB filter. We designed and simulated for CRLH transmission lines with one, two, four, and eight cells. A UWB filter using four cells CRLH is designed and fabricated to verify the results. The characteristics of designed filter have center frequency of 5GHz and relative bandwidth of 88%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.307-308
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• 2006

In this paper, we propose an ultra wideband pass filter of ring type with embedded stripline stub. The fractional bandwidth was 98 % at the center frequency of 8 GHz and insertion loss was below 1 dB in passband. Two kinds of dielectric materials with the permittivity of 7.8 and 40, respectively were adopted in evaluating the suggested filter structure. As the permittivity of material became larger, the size of filter smaller as expected without any sacrifice in filter performance. In summary, the suggested filter structure has smaller size due to the embedded stripline stub and can be minimized by adopting dielectric material with higher permittivity again.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.447-450
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• 2009

In this paper, binary pulse-antipodal modulation (2PAM) direct-sequence (DS) ultra-wideband (UWB) system is applied to multiple input multiple output (MIMO) system using vertical bell lab layered space-time (V-BLAST) structure to achieve high-data-rate communications over indoor wireless channels. The relationship between antenna dimension and BER performance of 2PAM DS UWB MIMO system is discussed. In the receiver of UWB-MIMO system, various MIMO detection algorithms such as zero-forcing (ZF), ZF-ordered successive interference cancellation (OSIC), minimum-mean-square-error (MMSE), MMSE-OSIC and maximum likelihood (ML) are comparatively studied.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.309-310
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• 2008

In this paper, we propose a novel D-ATR (Differential-Average Transmitted Reference) scheme for UWB (Ultra Wide Band) based on impulse radio. The proposed scheme utilizing differential coding at transceiver, does not cause half loss of data rate unlike the conventional TR (Transmitted Reference) and ATR (Average TR) systems which transmit additional reference signals. In addition, the proposed scheme may provide improved BER (Bit Error Rate) performance by averaging the received reference signals like the conventional ATR. The proposed D-ATR receiver produces the averaged reference template by considering both the detected data bit and the differential coding rule.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.313-317
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• 2003

In this paper, ultra-wideband frequency synthesizer which operates at S-band ($2{\sim}4GHz$) is designed. Designed frequency synthesizer shows the frequency range of $2.2{\sim}4.0GHz$ and output power of $-2{\sim}3dBm$. Phase noise characteristics are measured below -92.0dBc/hz at 100kHz offset frequency in entire sweep range and lock time is measured below 3.55ms. Spurious level is below -62.33dBc at comparison frequency of 1MHz.