• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.10
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• pp.1129-1136
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• 2008

In this paper, a dual polarized broadband antenna fed by L-shaped strip for the Korea PCS band and W-CDMA band is presented. To analyze the characteristics of the designed antenna, we used commercial simulation tool(HFSS). The designed antenna was fabricated and measured using HP8753D vector network analyzer. The measured impedance bandwidth(VSWR<1.5) is 560 MHz and the measured average gain is 6.56 dBi. The measured isolation characteristic between two ports is -14 dB(min.) $\sim$ -40 dB(max.). These results are proper for the mobile communication application and repeater antenna.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.12
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• pp.949-954
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• 2012

The K-PCS and W-CDMA dual band dielectric duplexer and bandpass filters have been designed and fabricated. The dual band duplexer consists of the separate monoblock K-PCS and W-CDMA duplexers using common antenna port. The coupling capacitance and I/O impedance matching have been designed to minimize the cross interference between the bands. Isolations of crosspoint between Tx and Rx in K-PCS and W-CDMA dualband were about 47 dB and 100 dB, respectively. On the other hand, isolations of Tx and Rx in K-PCS and W-CDMA were about 66 dB and 65 dB, respectively. The difference between 47 dB and 100 dB originated from the different center frequencies in Tx and Rx of K-PCS and W-CDMA bands. The coupling capacitance of the bandwidth, I/O capacitance of I/O matching and impedance matching, and various capacitances were important role to fabricate the dielectric duplexer and bandpass filters.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.12 s.103
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• pp.1179-1185
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• 2005

In this paper, novel internal antenna with its controllable resonant frequency is presented for triple-band or over mobile handsets. The operating range can include GSM(880${\~}$960 MHz), GPS(1,575$\pm$10 MHz), DCS(1,710${\~}$1,880 MHz), US-PCS(1,850${\~}$l,990 MHz), and W-CDMA(1,920${\~}$2,170 MHz). The proposed antenna is realized by combination of a half wavelength loaded line and a shorted monopole. A single shorting and feeding points are used and they are common to both antenna structures. By controlling a value of lumped inductance element between shorting point and ground plane, the antenna provides enough bandwidth to cover DCS, US-PCS, and W-CDMA respectively. When these higher bands are controlled by the values of inductance, resonant characteristics in GSM and GPS bands are maintained. In this work, maximum value of the inductor is limited within 3.3 nH to mitigate gain degradation from frequency tuning. As a result, measured maximum gain of antenna is -0.58${\~}$-0.30 dBi in the GSM band, -0.57${\~}$0.43 dBi in the GPS band and 0.38${\~}$1.15 dBi in the DCS/US-PCS/W-CDMA band. In higher band, the proposed antenna is certified that resonant frequency of about 240 MHz can be effectively controlled within gain variation of about 0.77 dB by simulation and measurement.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.2
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• pp.119-125
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• 2007

In this paper, a multi-band folded planar monopole internal antenna for mobile handset applications is proposed. The proposed antenna has multi-resonances, which is different from a conventional folded monopole antenna, and it provides a wide bandwidth at high frequency bands. The measured impedance bandwidth (VSWR < 3) is 180 MHz and 1880 MHz in lower and higher frequency bands, respectively. The proposed antenna can effectively cover most wireless communication bands including CDMA, GSM, GPS, DCS, PCS, and W-CDMA, WiBro and S-DMB.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.1
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• pp.7-13
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• 2007

In this paper, we have designed and fabricated a small size wide-band monopole antenna which can integrate the frequency of previous business mobile communication system by adding 4 PCS of post type parasitic element on top-loaded sleeve monopole antenna. We have observed the properties of return loss upon a parameter change of element, and we also examined radiation properties in the band of PCS, W-CDMA, WiBro, W-LAN and S-DMB in order to make sure the suggested antenna's wide-band properties. We have found that the proposed antenna has omni-direction in horizontal plane and figure eight-direction in vertical plane, and we could have good return loss($Return\;loss{\leq}-10\;dB$) and $1.14{\sim}3.66\;dBi$ gain in $1.67{\sim}3.55\;GHz$ of frequency range($B/W{\fallingdotsep}72%$).

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.4 no.1 s.6
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• pp.73-79
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• 2005

In this paper, a circuit for detecting a fine oscillation in an integrated PCS and W-CDMA receiver is presented. The advantages for this design are small size and flexible compatibility for system operation compared with the conventional method. The fine oscillation level can be detected by dB unit through selecting the receiver mode as PCS of 1.8 GHz range or W CDMA of 1.9 GHz range by a RF switch and monitoring the corresponding frequency band. Also, the circuit is designed to be flexible for other communication systems with the consideration of the required dynamic range of 75 dB.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.2
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• pp.50-55
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• 2008

In this paper, multi-band internal antenna which can adjust both resonant frequency and input impedance of antenna as using lumped inductor between shoring plate and ground plane is proposed. The structure of proposed antenna consists of PIFA (Planar Inverted F Antenna) structure and half-wavelength loaded line structure and has two shorting plates and one feeding plate. One shorting plate is shared. The operating frequency bands of designed antenna are GSM, GPS in the PIFA structure and DCS, US-PCS, W-CDMA in half-wave loaded line structure as varying the inductor value in 2.2nH, 3.3nH, and 4.7nH. As varying the inductor value in the shared shorting plate, input impedance of antenna is varied. To minimize the gain variation of antenna as adding lumped element, the inductor value is restricted at maximum of 6.8nH. The maximum gain of proposed antenna is measured as -1.60dBi in the GSM band, -1.16dBi in the GPS band, and 1.41dBi in the DCS/US-PCS/W-CDMA band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.10
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• pp.1103-1108
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• 2010

This paper proposes a new type of PIFA with a capacitor structure inserted into the feeding loop. It operates in GSM900, DCS, PCS, and W-CDMA frequency bands. By inserting the capacitor, it shows the effect of lowering the return loss from -2.73 dB to -6.26 dB at the parallel frequency, 2.01 GHz. The improvement of the poor radiation property near the parallel resonance frequency leads to a broadband operation in the upper band, DCS, PCS, and W-CDMA.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.9
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• pp.1642-1649
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• 2007

The lumped element isolators with temperature compensation magnetic circuits were designed in this paper. Isolators for mobile repeater at each band of K-PCS, GSM1900, W-CDMA, WiBro were fabricated by using optimum parameters of EM simulation, Form the results of this study, first of all, insertion loss at K-PCS band was below 0.2 dB and return loss was over 25dB. The bandwidth in isolation 23dB was found 30 MHz. Secondly, the figures of both losses at GSM1900 were 0.25dB and 23dB, respectively. The measured bandwidth in isolation 30dB was 60MHz. Thirdly, the losses at W-CDMA band were 0.15dB and 25dB. The bandwidth in isolation 24.8dB was found 60Mhz. Finally, the figures of both losses at Wibro band were 0.25dB and 23dB, respectively. The measured bandwidth in isolation 22.1dB was 100Mhz. In addition, the results of measured IMD were shown from 76.4dBc to 80.1dBc.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.4
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• pp.395-398
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• 2016

In this paper, a hybrid MIMO antenna for the mobile communication metal phone with auxiliary letter slot is designed and implemented. Auxiliary letter slot locates on the rear metal cover of the phone, and operates on LTE class 40 band. The slots of two letters are designed and operated with monopole+IFA hybrid antenna. Antenna satisfies under VSWR 3: 1 for LTE class 13 / LTE class 14 / CDMA / GSM / DCS / PCS / W-CDMA / LTE class 40 bands. Average gains and antenna efficiencies measured by the anechoic chamber were -5.57~-1.45 dBi and 27.75~71.6 %, respectively.