Chih-Ming Su

National Sun Yat-sen University, Kaohsiung, Kaohsiung, Taiwan

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Publications (23)14.21 Total impact

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    ABSTRACT: A simplified hand model for the study of internal mobile phone antenna for analyzing its impedance and radiation characteristics with the presence of the user's hand is proposed. The antenna in this study is a compact internal antenna having two separate resonant strips capable of generating two wide bandwidths for GSM and DCS operations. For the simplified hand model, it is a one-layer hand model including the user's forearm with a relative permittivity of 35 and a conductivity of 0.5 S/m. With this simplified hand model, efficient and reliable simulation study of the mobile phone antenna with the user's hand can be obtained. Detailed effects of the user's hand on the impedance and radiation characteristics of the internal mobile phone antenna are analyzed in this study. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2202–2205, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21935
    Microwave and Optical Technology Letters 08/2006; 48(11):2202 - 2205. · 0.59 Impact Factor
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    ABSTRACT: This paper proposes a one-layer simplified hand model incorporating the use of 3D FDTD simulation software, SPEAG SEMCAD-X (simulation platform for EMC, antenna design, and dosimetry) for achieving efficient simulation for hand-held device antennas. The case of the GSM/DCS internal mobile phone antenna with the proposed hand model is first presented. Effects of the proposed hand model including the user's forearm on the impedance and radiation characteristics of the internal antenna are analyzed. A second case of the DTV antenna in the PMP device with proposed hand model is also studied
    Antennas and Propagation Society International Symposium 2006, IEEE; 08/2006
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    ABSTRACT: The user's hand effects on the EMC GSM/DCS antenna embedded in the mobile phone have been presented. Although the EMC antenna is easy to be integrated into a mobile phone with nearby electronic components or conducting elements, the performance of the antenna is still greatly affected when a user's hand holds the mobile phone. Even when the phone was hand-held at the bottom, large efficiency drops have been observed, especially for the GSM operation
    Antennas and Propagation Society International Symposium 2006, IEEE; 08/2006
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    ABSTRACT: User's hand effects on an electromagnetic-compatible (EMC) internal dual-band mobile phone antenna for GSM/DCS operation are studied. The EMC internal antenna can be placed in direct contact with nearby conducting elements, without degradation in the antenna performances. Experimental and simulation studies are conducted to analyze the user's hand effects on this EMC antenna. Obtained results indicate that the user's hand affects not only the impedance matching of the antenna, but also the radiation characteristics including radiation patterns and efficiency. Effects of different positions of the user's hand holding the mobile phone are also analyzed and discussed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1563–1569, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21699
    Microwave and Optical Technology Letters 07/2006; 48(8):1563 - 1569. · 0.59 Impact Factor
  • Chih-Ming Su, Kin-Lu Wong, Brian Chen, Sam Yang
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    ABSTRACT: A novel integration design of a shorted patch antenna and a U-shaped shielding metal case for application in a mobile communication device is presented. The shorted patch antenna is mounted within the dented portion of the U-shaped shielding metal case, which can provide a coupling-free space for accommodating electronic components such as the RF modules/circuitry and battery in the mobile device. Thus, in this case, the shorted patch antenna can operate as an internal antenna having an electromagnetic compatibility (EMC) property with nearby electronic components. In addition, with the proposed integration design, the shorted patch antenna is isolated from the two side edges of the system ground plane of the mobile device. Hence, it can be expected that the effects of the user's hand on the performances of the antenna will be suppressed. The proposed integration design applied to a smart phone for Universal Mobile Telecommunications System (UMTS, 1920–2170 MHz) operation is studied. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1157–1161, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21552
    Microwave and Optical Technology Letters 05/2006; 48(6):1157 - 1161. · 0.59 Impact Factor
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    ABSTRACT: A novel patch antenna suitable to be applied in a mobile device as an internal antenna having an electromagnetic compatibility (EMC) property with nearby conducting elements is presented. The antenna is easily fabricated from a single metal plate and mainly comprises a top patch and an inverted-L vertical ground wall. Due to the presence of the inverted-L ground wall, which is perpendicular to the system ground plane of the mobile device, the possible fringing EM fields in the surrounding region of the antenna are suppressed. In this case possible coupling between the antenna and the nearby conducting elements is expected to be small, and thus degrading effects on the performance of the antenna are eliminated. A design example of the proposed antenna for Universal Mobile Telecommunication System (UMTS) 1920-2170 MHz operation in a mobile device is demonstrated and discussed.
    IEEE Transactions on Antennas and Propagation 12/2005; · 2.33 Impact Factor
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    ABSTRACT: A novel embedded DTV antenna for application in laptops has been proposed and studied. The proposed antenna can provide a wide operating bandwidth for DTV signal reception in the UHF band. In addition, the proposed antenna has a narrow width of 10 mm only, thereby making it very promising to be embedded within the spacing between the display and the casing of the laptop to operate as an embedded antenna. The proposed antenna also shows good radiation characteristics for frequencies across the operating band.
    Antennas and Propagation Society International Symposium, 2005 IEEE; 08/2005
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    ABSTRACT: Experimental and simulation studies for achieving optimized isolation between two internal UMTS and WLAN antennas for a dual-network wireless device are presented. Results indicate that the isolation of the two antennas is strongly affected by their relative position, and that isolation less than -30 dB is possible for the two antennas. It has also been observed that the isolation is strongly related to the excited surface current distributions in the system ground plane of the wireless device.
    Antennas and Propagation Society International Symposium, 2005 IEEE; 08/2005
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    ABSTRACT: An internal planar mobile phone antenna with a small vertical ground plane electrically connected to the system ground plane of the mobile phone is presented. The vertical ground plane can function as an effective shielding wall between the antenna and the nearby RF-shielding metal case or other associated elements in a mobile phone. In this case, the internal antenna can be compactly integrated within the mobile phone without degradation of the antenna performances. This vertical-ground design concept applied to an internal PIFA with a hollow shorting cylinder for a UMTS mobile phone is studied. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 597–599, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21061
    Microwave and Optical Technology Letters 07/2005; 46(6):597 - 599. · 0.59 Impact Factor
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    ABSTRACT: By embedding a simple arc-shaped slot in a circular-disk monopole antenna, an ultra-wideband (UWB, 3.1–10.6 GHz) operation with a controlled notched frequency band can be obtained. The arc-shaped slot is placed close to the boundary of the circular-disk monopole and has a length of about one-half wavelength of the desired notched frequency. The proposed slotted circular-disk monopole antenna showing UWB operation with a notched frequency band for rejecting the 5.8-GHz WLAN band is demonstrated. The effects of the dimensions of the arc-shaped slot on the notched frequency band are also analyzed. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 188–191, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20766
    Microwave and Optical Technology Letters 05/2005; 45(3):188 - 191. · 0.59 Impact Factor
  • Kin-Lu Wong, Liang-Che Chou, Chih-Ming Su
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    ABSTRACT: A novel dual-band flat-plate antenna with a shorted parasitic element for an internal laptop antenna for WLAN operation is presented. The proposed antenna is suitable to be integrated with the supporting metal frame for the display of the laptop and shows a low profile of 5 mm above the metal frame, thus making it easily embedded within the casing of the laptop as an internal antenna. Moreover, the proposed antenna can provide two separate impedance bandwidths of 190 MHz (about 8% centered at 2.4 GHz) and 2140 MHz (about 39% centered at 5.5 GHz), making it easily cover the required bandwidths for WLAN operation in the 2.4 GHz band (about 3.4% bandwidth required) and 5.2/5.8 GHz bands (about 13% bandwidth required). The proposed antenna is studied in detail in this study, and experimental and simulation results are presented.
    IEEE Transactions on Antennas and Propagation 02/2005; · 2.33 Impact Factor
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    ABSTRACT: A novel internal GSM/DCS planar antenna excited through a small printed circuit board (PCB) arranged perpendicular to the main PCB of the mobile phone is presented. The planar antenna including its feeding and shorting strips is parallel to the main PCB of the mobile phone, different from the configuration of the conventional internal patch antennas in which the shorting and feeding pins are both perpendicular to the main PCB. The antenna occupies a volume of about 7 × 20 × 40 mm3 and can provide two operating bands at about 900 and 1800 MHz for GSM/DCS operation. In addition, owing to the presence of the small PCB as a shielding wall, the GSM/DCS module or the battery can be place in close proximity to the antenna with very small or negligible effects on the antenna performances. The proposed antenna are presented and studied.
    01/2005;
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    ABSTRACT: A printed inverted-F monopole antenna excited using a microstrip-coupled feed is presented. The monopole antenna and the microstrip-coupled feed are printed on two sides of a dielectric substrate. The microstrip-coupled feed comprises a 50Ω microstrip feed-line and an open-ended microstrip section for coupling the signal to the monopole antenna. Two promising arrangements of the microstrip-coupled feed using a simple microstrip section and an L-shaped microstrip section are demonstrated. The experimental results of the constructed prototypes for operating in the 2.4-GHz WLAN band are presented. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 470–472, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20504
    Microwave and Optical Technology Letters 10/2004; 43(6):470 - 472. · 0.59 Impact Factor
  • Chih-Ming Su, Wen-Shyang Chen, Kin-Lu Wong
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    ABSTRACT: A T-shaped monopole antenna is a planar top-loaded monopole antenna and has the attractive feature of a low profile. We propose a novel dual-frequency metal-plate shorted T-shaped monopole antenna suitable for WLAN operation in the 2.4 GHz (2400-2484 MHz) and 5 GHz (5150-5350 and 5725-5875 MHz) bands. A prototype with a low profile of 4 mm only has been constructed. It is suitable for embedding within the narrow space between the top edge of the display and the housing of a laptop computer to operate as an internal antenna. Details of the proposed antenna and the experimental results are presented.
    Antennas and Propagation Society International Symposium, 2004. IEEE; 07/2004
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    ABSTRACT: Planar inverted-F antennas (PIFAs) have been very popular as an internal antenna in small handheld wireless communication devices. Recently, in many wireless devices, a digital camera is embedded and is in competition with the PIFA internal antenna for the very limited space on the system circuit board. We propose a novel design of the PIFA with a large hollow shorting cylinder for application in a mobile phone with an embedded digital camera. The hollow shorting cylinder has a large diameter (8 mm in this case), and it is easy to fit the lens of a practical embedded digital camera inside it. In this case the proposed PIFA and the embedded digital camera together occupy a minimum space, and very small or negligible coupling effects of the embedded camera with the PIFA are expected. A design example of the proposed PIFA for application in a UMTS (Universal Mobile Telecommunication System, 1920-2170 MHz) mobile phone is demonstrated. The experimental results obtained are also presented.
    Antennas and Propagation Society International Symposium, 2004. IEEE; 07/2004
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    ABSTRACT: A novel dual-frequency shorted T-shaped monopole antenna is proposed. The T-shaped monopole is comprised of two horizontal arms of different lengths, which generate two separate resonant modes for the desired dual-frequency operation, and one vertical arm is short-circuited to a ground plane through an inverted-L strip for good impedance matching. A prototype suited for WLAN operation in the 2.4- and 5-GHz bands for a laptop as an internal antenna is constructed and tested. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 202–203, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20093
    Microwave and Optical Technology Letters 03/2004; 41(3):202 - 203. · 0.59 Impact Factor
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    ABSTRACT: A printed linear array antenna comprising three half-wave folded dipole elements with the first two elements operating in the 5 GHz band and the third one operating in the 2.4 GHz band for WLAN operation is presented. The array antenna provides directional radiation patterns with vertical polarisation for frequencies across both the 2.4 and 5 GHz WLAN bands, and the measured antenna gain is 3.5-3.7 dBi for the 2.4 GHz band and 4.5-5.0 dBi for the 5 GHz band.
    Electronics Letters 12/2003; · 1.04 Impact Factor
  • Chih-Ming Su, Wen-Shyang Chen, Kin-Lu Wong
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    ABSTRACT: A novel two-element metal-plate antenna arranged in a compact geometry and easily constructed from a single metal plate is presented. The antenna shows a high antenna-gain level (> 4.0 dBi) and is suitable for WLAN operation in the 5.2/5.8-GHz bands (5150–5350 MHz/5725–5875 MHz). The antenna-gain level obtained can even be larger than 5.0 dBi for practical applications where the antenna is required to be placed in close proximity to a large metal plate, such as the metal plate or metal frame used to support the display of a laptop. Details of the proposed antenna design and obtained experimental results are presented. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 246–249, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11182
    Microwave and Optical Technology Letters 08/2003; 39(3):246 - 249. · 0.59 Impact Factor
  • Chih-Ming Su, Wen-Shyang Chen, Kin-Lu Wong
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    ABSTRACT: A novel compact dual-band metal-plate antenna is presented. The antenna is easily constructed by bending a metal plate, which consists of a longer arm as the grounding portion and two shorter arms as the major radiating portions for controlling the resonant modes at about 2.4 and 5.2 GHz, into a structure having a compact cross section of 1 × 3 mm2 and a length of 60 mm. The antenna is easily fed by using a 50Ω mini coaxial line, and is suitable to fit in possible narrow spaces within a communication device. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 113–115, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10987
    Microwave and Optical Technology Letters 05/2003; 38(2):113 - 115. · 0.59 Impact Factor
  • Chih-Ming Su, Hong-Twu Chen, Kin-Lu Wong
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    ABSTRACT: An inverted-L slot antenna for wireless local area network (WLAN) operation in the 2.4-GHz band (2400–2484 MHz) is presented. The inverted-L slot antenna is obtained by transforming a linear slot into an inverted-L shaped, which makes it very suitable to be placed at the corners of the display panel of a notebook computer. A prototype has been constructed and tested, and good antenna gain and dual-polarization radiation characteristics for WLAN operations are observed. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 315–316, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10905
    Microwave and Optical Technology Letters 04/2003; 37(5):315 - 316. · 0.59 Impact Factor