• Proceedings of the IEEK Conference
• /
• 2008.06a
• /
• pp.435-436
• /
• 2008

This paper presents a dual band frequency synthesizer for GSM and Wideband CDMA which is designed in a standard 0.13um CMOS 1P6M process. The shared components include phase frequency detector (PFD), charge pump (CP), loop filter, integer frequency divider(128/129 DMP, 4bit PC, 3bit SC) and Low noise Ring-VCO. A high-speed low power dual modulus prescaler is proposed to operate up to 2.1GHz at 3.3V supply voltage with 2mW power consumption by simulation. The simulated phase noise of VCO is -101dBc/Hz at 200kHz offset frequency from 1.9GHz.

• 한국ITS학회:학술대회논문집
• /
• 2003.11a
• /
• pp.320-323
• /
• 2003

• 한국ITS학회:학술대회논문집
• /
• 2004.11a
• /
• pp.111-114
• /
• 2004

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.18 no.12
• /
• pp.1337-1344
• /
• 2007

It is shown that inverted ${\pi}$ feeder affects the gain improvement for the internal antenna of mobile phone. Generation of current on the inverted ${\pi}$ feeder, by the modification of conventional feeding structure for the PIFA and IFA, can apply T matching theory to the new feeder. Therefore, inverted ${\pi}$ feeder based on the T matching theory makes higher radiation resistance, and also increases the gain. To verify inverted ${\pi}$ feeding effect, feeder is applied to GSM/DCS dual band conventional PIFA, and measured return loss and patterns. By measurement, it's shown that this new feeding antenna has $0.23{\sim}0.84$ dB higher average gain for GSM band and $0.01{\sim}1.74$ dB higher average gain for DCS band than conventional fed PIFA without resonant frequency change.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.13 no.2
• /
• pp.42-49
• /
• 2014

A broadband antenna using a main and a sub antenna for the mobile communication terminal such as mobile phone and ITS terminal is designed. Two antennas are based on the hybrid antenna that is operating both a monopole and a IFA(Inverted F Antenna). It's applied the transmission line to connect both antennas. Sub antenna located in small space of the terminal allows space usability for the terminal design. Antenna for the hexa-frequency band of LTE700, CDMA, GSM, DCS, PCS and WCDMA is designed and implemented on the bare PC board that is same size of the mobile phone. This antenna was measured 3 : 1 VSWR over the whole design band. And average gains and efficiencies were-3.78 ~ -2.62dBi and 41.9 ~ 54.73% for LTE700/CDMA/GSM frequency band, -3.75 ~ -1.84dBi and 42.19 ~ 65.46% for DCS/PCS/WCDMA frequency band.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.7 no.4
• /
• pp.71-75
• /
• 2008

A folded monopole antenna is proposed for mobile communication applications. The proposed antenna covers CDMA and GSM at low frequency band, and it has a wide bandwidth (6.85 GHz) at high frequency band to cover GPS, DCS, USPCS, UHfS, WLAN (2.4, 5.2, 5.8 GHz), and the future application of IEEE 802.16e mobile WiMAX.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.06a
• /
• pp.572-575
• /
• 2007

In this paper, we proposed a internal antenna for Quad band for GSM/DCS/USPCS/WCDMA Handset. Antenna Structure is designed to PIFA type. Antenna planed two independence patterns to reduce the size for efficiency and used shoting pin and inverse seven_type slit. Also they miniaturized the antenna construction electronic length for duty. furthermore, they designed and producted the antena height for 5w and ground term for 40*80mm. It is because they have wondered the thickness of terminal. used of for reduce size efficiently. The radiation pattern characteristic of antenna is compared and analyzed E-plane and H-plane at 920MHz, 1800MHz.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.6
• /
• pp.213-218
• /
• 2007

We propose a compact internal quard-band antenna with sufficient impedance bandwidths and gains for the GSM(Global Systems for Mobile), GPS(Global Positing System). DCS(Digital Codeless System), PCS (Personal Communication System) operation. The proposed antenna on a substrate. which is small enough to be installed in practical mobile phones, has heights of only 6mm from the substrate. In addition, the proposed antenna decreases the construction complex on the substrate. The GSM ($880MHz{\sim}960MHz$) GPS(1575MHz) DCS($1710MHz{\sim}1880MHz$). PCS($1750MHz{\sim}1870MHz$) bands. Details of the design and analysis of the proposed antenna are described and the experimental results of the constructed prototype are presented.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.2
• /
• pp.136-142
• /
• 2010

In this paper, the microstrip antenna for penta-band service is proposed. It is designed for a wide band characteristic based on a monopole line combined with a triangular patch structure which has two slits. Total antenna size is $35\;mm{\times}20\;mm$ and it was fabricated on FR-4 substrate($\varepsilon_r=4.4$) which has $35\;mm{\times}75\;mm{\times}1\;mm$ size and a microstrip line with impedance 50 ohm is used. Experimental result shows the impedance bandwidth($VSWR{\leq}3$) of the proposed antenna operated within GSM/DCS/USPCS/UMTS/Bluetooth frequency band. The resonance frequency of the proposed antenna is 0.92, 1.97, 2.45 GHz and the average gain is -2.18, -0.66, -0.58 dBi. Also, the radiation efficiency is 60, 85, 87%. The fabricated antenna is satisfied with the aimed impedance bandwidth ($VSWR{\leq}3$) in GSM/DCS/ USPCS/UMTS/Bluetooth frequency band.

• Journal of the Korea Society of Computer and Information
• /
• v.15 no.8
• /
• pp.59-66
• /
• 2010

In this paper, the internal antenna for mobile communication handset which is able to control both coupling coefficient and resonant frequency without any major modification of radiator and ground plane of antenna. 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($1,575{\pm}10MHz$), DCS(1,710~1,880MHz), US-PCS(1,850~1,990 MHz), and W-CDMA(1,920~2,170 MHz). The proposed antenna is realized by combination of a half wavelength loaded line antenna and PIFA(Planner Inverted F Antenna). A single shorting and feeding points are used and they are common to both antenna structures. One of two inductors which is placed at each shorting post, one inductor is for adjusts amount of coupling, and the other controlling the resonant frequency in DCS/US-PCS/WCDMA bands. The inductance range for control of input impedance is between 0nH and 6.8nH, and each of gain variation in GSM, GPS and DCS/US-PCS/WCDMA band is under 0.15dBi, 0.73dBi and 0.29dBi. The inductance range for control of the resonant frequency is between 1640MHz and 2500MHz, and each of gain variation in GSM, GPS and DCS/US-PCS/WCDMA band is under 0.46dBi, 0.53dBi and 0.8dBi.