Won-il Chang

Daejeon University, Daiden, Daejeon, South Korea

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Publications (6)2.23 Total impact

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    ABSTRACT: In this paper, we propose a low loss 60GHz Radio AiP (Antenna-in-Package) solution for mobile applications. To achieve this low loss AiP, essential passive elements such as transmission lines, transitions, filters and antennas are developed using low temperature co-fired ceramic (LTCC). In order to make packages power efficient, air cavities are inserted; insertion loss is improved by up to 58% for stripline (SL). In order for them to be integrated into mobile devices, planar patch array antennas are developed as 2×1, 2×2, and 4×4 configurations. They show relative gains of 7 dBi, 7 dBi and 14 dBi, and 3 dB beam width of 30°, 36°, and 19°. We deal with interconnection issues with the wire-bonding technique. In conjunction with proper compensation circuits, 0.64dB of insertion loss is realized over the wide bandwidth (53∼67GHz). In order to realize low power 60GHz radio for mobile applications, an OOK modulator and demodulator are developed in CMOS technology. These can handle the data at Gbps (2Gbps and 5Gbps, respectively) speed with low power dissipation (14.4mW and 14.7mW, respectively). In the end, we demonstrate a low power 60GHz Radio AiP solution for video streaming in mobile applications.
    01/2011;
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    ABSTRACT: This paper proposes a simple low-temperature co-fired ceramic (LTCC) integrated transmitter using sub-harmonic amplitude shift-keying modulation for 60-GHz wireless communications applications. The transmitter system-on-package (SoP) has been monolithically implemented with a six-layer LTCC block embedding a resonator, modulator, and antenna and two active circuits, including a negative resistance generator and frequency doubler on the block. The transmitter SoP integrating whole millimeter-wave circuitry is as small as 26 times 18 times 0.6 mm<sup>3</sup>, which needs external interfaces only for supplying dc power and digital input signal. The fabricated transmitter SoP reveals a bit error rate of 10<sup>-11</sup> and good eye pattern through a 2.5-m transmission of 800-Mb/s data.
    IEEE Transactions on Microwave Theory and Techniques 09/2007; · 2.23 Impact Factor
  • Won-il Chang, Dong Yun Jung, Chul Soon Park
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    ABSTRACT: An SMD type balun with a frequency range from 10 GHz to 25 GHz in a low temperature co-fired ceramic (LTCC) substrate is designed and measured. To reduce the effect of misalignment in the multilayer coupler, we propose a novel multilayer coupler structure which is insensitive to misalignment. The package has ports on the ground plane for the SMT, and a cover on top of the circuit to protect the circuit. Every transmission line is simulated as an embedded micro-strip line to account for the cover effect. All the internal ports are connected to the output ports at ground plane through via transition. The total number of LTCC layers is 5 including the cover layer. The overall dimension is as small as 5.5 mm × 5.5 mm × 0.5 mm.
    Radio and Wireless Symposium, 2006 IEEE; 02/2006
  • Won-il Chang, Dong Yun Jung, Chul Soon Park
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    ABSTRACT: A 60GHz surface wave reduced type antenna is presented which can be used in a 3D system in package (SiP) with a low temperature co-fired ceramic (LTCC) substrate. Using a simple magnetic current model, we derive the surface wave reduction condition of our design and show that the LTCC substrate has a very similar condition to the derived condition. Using the result, we design a very simply structured surface wave reduced circular patch antenna. The conventional rectangular patch array antenna is also designed and measured for the purpose of comparison with the designed surface wave reduction type antenna.
    Microwave Conference Proceedings, 2005. APMC 2005. Asia-Pacific Conference Proceedings; 01/2006
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    ABSTRACT: We demonstrate a 36 times 12 times 0.9mm<sup>3</sup> sized compact monolithic LTCC SiP transmitter (Tx) for 60GHz-band wireless communication terminal applications. Five GaAs MMICs including mixer, driver amplifier, power amplifier and two of frequency doublers have been integrated onto LTCC multilayer circuit which embeds a stripline BPF and a microstrip patch antenna. A novel CPW-to-stripline transition has been devised integrating air-cavities to minimize the associated attenuation. The fabricated transmitter achieves an output of 9dBm at a RF frequency of 60.4GHz, an IF frequency of 2.4GHz, and a LO frequency of 58GHz. The up-conversion gain is 11.2dB; while the LO signal is suppressed below 33.4dBc, and the spurious signal is also suppressed below 27.4dBc. This is the first report on the LTCC SiP transmitter integrating both a BPF and an antenna. A 60 GHz communication was demonstrated
    Microwave Symposium Digest, 2005 IEEE MTT-S International; 07/2005
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    ABSTRACT: A 60GHz-band transmitter system-in-package (SiP) has been developed for future wireless communications applications. GaAs MMIC chipsets including a power amplifier, a driver amplifier, a mixer, and multipliers have been integrated on a LTCC multi-layer circuit for the heterodyne transmitter. The size of the whole transmitter LTCC module is 10mm × 21mm × 1mm. With an IF frequency of 2.4GHz and a LO frequency of 58GHz, 60.4GHz output of 11dBm is achieved, and the total gain is 12 dB. The link test for a 60GHz wireless communication shows that the transmitter communicates well with the receiver without any signal distortion.
    Compound Semiconductor Integrated Circuit Symposium, 2004. IEEE; 11/2004