• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.61-62
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• 2018

In this paper, we studied a wideband double-sided dipole antenna operating at 3.5 GHz (WiMAX) band. The each printed dipoles are placed on the both sides of the substrate. It can be easily implemented and is suitable for connection with an active circuit. In order to obtain wideband printed dipole characteristics, thick rectangular shaped dipole is adopted. Feeding Circuit for dipole array and balun were designed for impedance matching with a $50{\Omega}$ microstrip feed line. The antenna is designed by simulation for an operation in the frequency range of 3.4~3.7 GHz Simulation results show that the maximum gain in the 3.5 GHz band is 5.5 dBi and the bandwidth with VSWR less than 2 is about 1 GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.1
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• pp.27-35
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• 2013

In this paper, a compact, broadband quasi-Yagi antenna utilizing balance analysis of the ultra-wideband microstrip-to-coplanar stripline(MS-to-CPS) balun is proposed. The antenna size was reduced by removing the reflector on bottom layer and ground plane is used as a reflector. A planar balun that transforms from microstrip(MS) to balanced coplanar stripline(CPS) is characterized in the amplitude and phase imbalances at CPS output ports are investigated and discussed. As compared with the conventional balun, the proposed MS-to-CPS balun demonstrated very wideband performance from 7 to over 20 GHz. From the simulation study, amplitude and phase imbalances are within 1 dB and ${\pm}5^{\circ}$, respectively. The implemented antenna provides very wide bandwidth from 6.9 to 15.1 GHz(74.5 %). The gain of the antenna is from 3.7 to 5.5 dBi, the front-to-back ratio is more than 10 dB, and the nominal radiation efficiency is about 94 %.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.11
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• pp.1414-1416
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• 2016

In this paper, a SWB (Super-WideBand) dipole antenna with self-complementary structure is proposed for signal intelligence. The proposed antenna consists of a self-complementary dipole antenna and a tapered balun for balanced feeding. The measured -10 dB reflection bandwidth of the proposed antenna is more than 28:1 (0.73-20 GHz) and 3 dB axial ratio bandwidth is 3.25:1 (1.91-6.22 GHz) with RHCP (Right Hand Circular Polarization) at +z direction. The measured radiation patterns are omni-directional in lower frequency band and bi-directional in higher frequency band. The measured peak gain within -10 dB reflection bandwidth varies from 2.83 dBi to 7.66 dBi.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.1
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• pp.76-80
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• 2011

This paper has proposed a 3~5 GHz low-power and wideband LNA(Low Noise Amplifier), which has been implemented in a 0.18-${\mu}m$ CMOS technology. The proposed LNA has basically the noise-cancelling topology to achieve a balun-function, wideband input matching, and relative low noise figure. In addition, it has utilized a 2nd-order LC-band-pass filter(BPF) as its output load to achieve higher power gain and lower noise figure with the lowest dc power consumption among previously reported works. The proposed amplifier consumes only 3.94 mA from a 1.8 V supply voltage. The simulation results show a power gain of more than +17 dB, a noise figure of less than +4 dB, and an input IP3 of -15.5 dBm.

• Journal of IKEEE
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• v.24 no.2
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• pp.536-542
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• 2020

This paper presents a nature-inspired wideband sprout-leaf shaped antenna with end-fire radiation pattern. A sprout-leaf shape angled-radiator was designed for wide beamwidth radiation patterns for motion detection sensors. An extended and truncated ground plane was used as a reflector for end-fire radiation patterns. To feed the balanced radiator, a broadband microstrip (MS) to coplanar stripline (CPS) balun was utilized with excellent amplitude and phase balance. The proposed antenna demonstrates wide frequency bandwidth from 8.5 to 14.5 GHz with wide beamwidth and the radiation efficiency of 90%. The measured gain is from 4 to 5 dBi and front-to-back ratio was 10 to 20 dB. It has been shown that the proposed antenna can be used for imaging sensors, phased array systems, and radars that require a wide bandwidth and a directional radiation pattern.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.12
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• pp.52-58
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• 2009

We propose a folded monopole antenna with loads, and analyze the roles of design parameters which affect the return loss of the proposed antenna. VSWR < 3 bandwidth of the antenna is 30 ~ 2000 MHz, ranging from the HF/VHF/UHF bands. For operating travelling antenna, we connect six loads at the end of the antenna. The reflected wave is drastically reduced due to the six loads. For improved return loss properties, we use Klopfenstein tape that determine positions and values of six loads. The propose antenna has omni-directional radiational patterns like that of conventional monopole antennas. For wideband impedance transformation, we use the balun which operating frequency region is 10 ~ 1900 MHz. We expect the proposed antenna has important role for the wideband and multi-rold multi-functional communication systems.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.10
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• pp.1166-1174
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• 2008

In this paper, design of a $2{\sim}18$ GHz wideband cavity-backed spiral antenna is investigated. Firstly, an arm pattern and a backing cavity of a cavity-backed spiral antenna are designed based on the design theory of an Archimedean spiral antenna as well as by using CST's MWS. VSWR, axial ratio, and HPBW(Half Power Beam Width) characteristics are considered in the simulation. Secondly, a Marchand coaxial balun is designed to meet the required VSWR within the frequency band of operation. Finally, the validity of these approaches is verified by comparing the simulated results with measured ones.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.9
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• pp.886-894
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• 2014

A wideband bow-tie antenna fed by wideband microstrip-coplanar stripline(CPS) balun and band notch structures that can be applied to bow-tie antenna are proposed in this paper. In order to increase bandwidth, bow-tie radiators are reshaped so that the surface current flows continuously, and wideband impedance matching is achieved by adjusting strip width and spacing of CPS feeding line. The VSWR is measured as 2:1 over the wide frequency range of 2.3~12 GHz. The fabricated antenna size is $60mm{\times}60mm$. In order to achieve the band-notch function at WLAN(5.8 GHz), ${\lambda}/4$ folded-slits located ${\lambda}/4$ away from feeding point are utilized. To minimize the slit size, folded-slit type is adopted. The measured VSWR is 7:1 and gain attenuation is 14 dB at 5.8 GHz.

• Journal of Advanced Navigation Technology
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• v.22 no.2
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• pp.141-147
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• 2018

We propose a wideband 4-way quadrature divider for global navigation satellite system (GNSS). The proposed divider consists of one balun and two 2-way quadrature dividers. In the balun, the input power is divided by a wilkinson divider and the out of phase characteristic is achieved by ${\pm}90^{\circ}$ metamaterial transmission line phase shifters applied two output ports. The structures of two quadrature dividers is similar to that of the balun, but the phase shifters of two output ports are exchanged by ${\pm}90^{\circ}$ metamaterial transmission line. Metamaterial transmission lines are designed by using five LC loaded transmission line (LCL-TL) unit cells. The fabricated 4 way quadrature divider has the phase characteristic of $90^{\circ}{\pm}10^{\circ}$ in 1.165 - 1.61 GHz.

• Journal of IKEEE
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• v.17 no.2
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• pp.176-181
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• 2013

This paper presents a CMOS impulse radio ultra-wideband (IR-UWB) receiver implemented using IBM 0.13um CMOS technology for inner/inter-chip wireless interconnection. The IR-UWB receiver is based on the non-coherent architecture which removes the complexity of RF architecture (such as DLL or PLL) and reduces power consumption. The receiver consists of three blocks: a low noise amplifier (LNA) with active balun, a correlator, and a comparator. Simulation results show the die area of the IR-UWB receiver of 0.2mm2, a power gain (S21) of 12.5dB, a noise figure (NF) of 3.05dB, an input return loss (S11) of less than -16.5dB, a conversion gain of 18dB, a NFDSB of 22. The receiver exhibits a third order intercept point (IIP3) of -1.3dBm and consumes 22.9mW of power on the 1.4V power supply.