• Journal of Advanced Navigation Technology
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• v.14 no.1
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• pp.11-19
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• 2010

In this paper, H-plane filtering-horn antenna operating at millimeter frequency band is proposed with embedded filter and three-layered dielectric lens for frequency selection and maintenance of main beam direction, respectively. The waveguide-typed filter and H-plane sectoral horn antenna are replaced with considerably size-reduced PCB substrate-typed filtering antenna using via fences and several posts. The waveguide-typed filter and H-plane sectoral horn antenna were designed in air-filled waveguide and then combined into size-reduced PCB substrate. For the control of the thickness of dielectric lens, single and multi dielectric lens have been employed. As a result of antenna gain, 8 and 13.5 dBi have been obtained at 41.5 GHz, respectively, from the simulations of single and multi-lens antennas.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.10
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• pp.103-108
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• 2004

In this paper, a compact patch antenna with four T-slits fed by crossed aperture coupling is proposed for miniaturized Portable GPS handsets. The mechanism for compact size antenna is investigated with the behavior of the currents on the radiating patch. The equivalent surface current path due to the slits is lengthened, reducing the resonant frequency at a fixed patch size. The results of embedded T-slits for compact antenna size show that the resonant frequency is significantly lowered from 2.545GHz to 1.575GHz, corresponding to a 44.65% antenna size reduction compared to reference design. Experimental results show that good CP radiation patterns are obtained and impedance bandwidth (VSWR $\leq$ 2), 3dB axial ratio are about 21MHz, 19MHz at the center resonant frequency, respectively.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.6
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• pp.1169-1176
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• 2018

The C-band omni-directional antenna for drone control is mounted on the top or bottom and used to configure the communication link. The communication link is affected by the LOS depending on the mounting position of the omni-directional antenna. In this paper, two kinds of embedded antennas were designed with a commercial simulation tool CST MWS, and EM analysis was performed to consider the mounting environment. Also, we propose the PTMP ground antenna to control a large number of drones. The ground antenna has a communication link of 30km, and it consists of four sector antennas in the horizontal direction and one directional antenna at the top.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.9
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• pp.1991-1998
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• 2015

This paper presents the antenna factor characteristics of a calculable dipole antenna with a hybrid balun, installed above ground plane vertically and horizontally, using Method of Moments (MoM). An expression for the antenna factor is formulated using the concept of power mismatch loss. The input impedance and effective length of the antenna, which are in the formula of the antenna factor, are calculated using the MoM. The results show that the antenna factors above a ground plane are agreed with the free space antenna factors within ± 0.14 dB. The horizontal antenna factors are varied more by 0.2 dB than the vertical antenna factors.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.3 s.118
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• pp.288-297
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• 2007

The novel internal monopole chip antenna of penta-band operation for GSM850/GSM900/DCS/USPCS/WCDMA bands for mobile phones is proposed. This antenna occupies a small volume $8\times3.2\times20mm^3$ and is suitable to be embedded in a mobile phone as an internal antenna. The minimization of the proposed antenna was realized by using spiral line structure and meander line structure on FR-4 of dielectric$(\varepsilon_r=4.4)$. The designed antenna has the wide-band operation in the upper band by overlapping high order resonances. The measured bandwidth of this antenna (VSWR>3) is 150MHz$(1,030\sim1,180\;MHz)$ in the lower band operation and 650 MHz$(1,760\sim2,410\;MHz)$ in higher band operation. The measured radiation efficiency within bandwidth(VSWR 3:1) is over 50 %. The antenna has been designed by a commercial software HFSS.

• Journal of Advanced Navigation Technology
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• v.13 no.5
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• pp.714-719
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• 2009

In this paper, a compact antenna with band-rejected characteristic for Ultra-Wideband(UWB) applications is proposed. The designed antenna not only shows sufficient impedance bandwidth but has band-rejected characteristic for the frequency band of 5.15~5.825GHz limited by IEEE 802.11a and HIPERLAN/2. To obtain both properties of wideband band rejection, the techniques of a partial ground plane and embedded thin U-slot into planar radiator are used respectively. A designed antenna satisfied a VSWR less than 2:1 for the frequency band of 3.1~10.3GHz with band rejection of 4.90~5.92GHz.

• The Journal of the Korea Contents Association
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• v.7 no.7
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• pp.24-30
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• 2007

This paper observed characteristics of a triangular microstrip patch antenna with T-slot. When a narrow horizontal slot or vertical slot is embedded in a triangular microstrip antenna, we investigated variations of dual resonant frequency according to slot lengths and then we could make a triangular microstrip antenna with T-type slot suitable to a very low dielectric substrate. The proposed antennas used a dielectric substrate which has relative dielectric constant ${\epsilon}_r=3.38$ and a height of 8 [mils] (=0.2032mm) and antenna characteristics of horizontal or vertical slot antennas are compared by a ensemble 8.0 simulator. Theoretical and experimental results of manufactured antennas are compared.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.25-31
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• 2014

In this paper, a modified Alford loop antenna for on-body communication system is proposed. The proposed antenna operating in the ISM band is designed with consideration of human body effect. One of advantages of the Alford loop antenna structure is low-profile, however the Alford loop antenna is not suitable for on-body devices since it does not have a ground plane for other electronic part of on-body system and requires balanced feeding structure. To be embedded on on-body devices, the proposed antenna is design with the unbalanced feed structure and ground. The performance of the proposed antenna is simulated and measured when it is placed on the human body phantom to consider the effect of the human body. The proposed antenna a 10 dB return loss bandwidth over the ISM band and monopole-like radiation pattern with low-profile. The antenna has the surface of appropriate for on-body communication environment.

• Journal of Advanced Navigation Technology
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• v.25 no.6
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• pp.523-529
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• 2021

This paper shows the design and fabrication of antenna embedded in marine buoy for marine IoT service, especially automatic identification system of fishing gears. Frequency band of proposed antenna has dual band of 433 MHz and 920 MHz considering marine IoT extension. Dual pattern monopole type for 920 MHz and meander type for 433 MHz are adopted in the proposed antenna. Voltage standing wave ratio is obtained 1.548 at 433 MHz and obtained 1.5 of mean value at 920 MHz band by measuring the fabricated antenna. The maximum antenna gain of 3.83 dBi is measured at 902 MHz among 920 MHz band, while antenna gain of 433 MHz is obtained 1.18 dBi. Although antenna gain of 433 MHz is low than 920 MHz band, this gain is larger than desired value of -5 dBi. And, it is confirmed that other measured values meet the performance criteria for archiving communication distance of 10 km between marine buoy and fishing ship in automatic identification system of fishing gears.

• ETRI Journal
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• v.35 no.1
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• pp.51-57
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• 2013

In this paper, a small internal antenna for a mobile handset is presented using multiband, wideband, and high-isolation multiple-input multiple-output techniques. The proposed antenna consists of three planar inverted-F antennas (PIFAs) that operate in the global system for mobile communication (GSM900), the digital communication system (DCS), the personal communication system (PCS), the universal mobile telecommunication system (UMTS), and wireless local area network (WLAN) bands with a physical size of $40mm{\times}10mm{\times}10mm$. A resonator attached to the folded PIFA creates dual resonances, achieving a wide bandwidth of approximately 460 MHz, covering the DCS, PCS, and UMTS bands; a meander shorting line is used to improve impedance matching. Additionally, a modified neutralization link is embedded between diversity antennas to enhance isolation, which results in a 6-dB improvement in the isolation and less than 0.1 in the envelope correlation coefficient evaluated from the far-field radiation patterns. Simulation and measurements demonstrate very similar results for S-parameters and radiation patterns. Peak gains show 3.73 dBi, 3.77 dBi, 3.28 dBi, 2.15 dBi, and 5.86 dBi, and antenna efficiencies show 56.15%, 72.15%, 68.59%, 52.92%, and 82.93% for GSM900, DCS, PCS, UMTS, and WLAN bands, respectively.