Author
Zhi Ning Chen
Other affiliations: Agency for Science, Technology and Research, University of Tsukuba, National University of Singapore
Bio: Zhi Ning Chen is an academic researcher from Institute for Infocomm Research Singapore. The author has contributed to research in topics: Antenna (radio) & Dipole antenna. The author has an hindex of 21, co-authored 59 publications receiving 1600 citations. Previous affiliations of Zhi Ning Chen include Agency for Science, Technology and Research & University of Tsukuba.
Papers published on a yearly basis
Papers
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TL;DR: The planar monopole antenna is shown to provide extremely wideband impedance characteristics and the radiation performance is also shown to be acceptable over a wide frequency range.
Abstract: The planar monopole antenna is shown to provide extremely wideband impedance characteristics. Recently, many techniques to tailor and optimize the impedance bandwidth of these antennas have been investigated. These include the use of bevels, slots and shorting posts. These antennas are becoming popular, and have been proposed for modern and future wideband wireless applications. The radiation performance is also shown to be acceptable over a wide frequency range.
382 citations
TL;DR: In this article, a wideband shorted planar monopole with a bevel was proposed and demonstrated to increase the impedance bandwidth by combining bevelling and a shorting technique.
Abstract: A new wide-band shorted planar monopole with a bevel is presented The numerical simulations and measurements demonstrate that the impedance bandwidth of a wide-band planar square monopole is shown to increase dramatically by combining bevelling and a shorting technique The radiation pattern stability is also discussed
233 citations
TL;DR: In this paper, a probe-fed halfwavelength strip was used to suppress the high cross-polarization levels of the suspended plate antenna, which result mainly from the undesired excitation of higher-order modes.
Abstract: A new feeding scheme for enhancing the radiation performance of a suspended plate antenna with a broad bandwidth is presented experimentally. By means of a probe-fed half-wavelength strip, the high cross-polarization levels of the suspended plate antenna are suppressed effectively, which result mainly from the undesired excitation of higher-order modes. Measurements on the antenna with the proposed feeding structure have demonstrated the good performances with a high ratio of co- to cross-polarization levels and stable radiation patterns across a 20% bandwidth for VSWR/spl les/2 : 1.
101 citations
TL;DR: In this article, the use of an asymmetrical feed probe is shown to significantly increase the impedance bandwidth of a square planar monopole antenna, and the effect of the asymmetry on radiation patterns is also shown.
Abstract: The use of an asymmetrical feed probe is shown to significantly increase the impedance bandwidth of a square planar monopole antenna. The feed probe is offset from the center of the planar element. The optimum location of the feed probe is shown to increase the impedance bandwidth by a factor of 3.4. The effect of the asymmetry on radiation patterns is also shown. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 156–158, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11313
76 citations
TL;DR: In this article, the authors proposed a wideband single-feed, circularly polarized, stacked, square, slotted microstrip patch antenna for radio-frequency identification-reader applications, which consists of an upper square asymmetric slotted patch, stacked over a lower square uneven slotted radiating patch and a microstrip stub, along with a coaxial feed.
Abstract: A wideband, single-feed, circularly polarized, stacked, square, slotted microstrip patch antenna is proposed for radio-frequency-identification-reader applications. The proposed antenna consists of an upper square asymmetric slotted patch, stacked over a lower square asymmetric slotted radiating patch and a microstrip stub, along with a coaxial feed. The wideband circularly polarized radiation of the antenna is achieved using a microstrip stub in the lower patch and a stacked slotted square patch. The proposed antenna is designed using a combination of low-cost FR4 substrate and foam. The measured 10 dB return-loss bandwidth of the antenna was around 21% (833 MHz to 1033 MHz), and the 3 dB axial-ratio bandwidth of the antenna was around 13.4% (835 MHz to 955 MHz). The gain was around 7.0 dBic over the 3 dB axial-ratio bandwidth. The overall antenna volume was 0.601?0 × 0.601?0 × 0.895?0 (where ?0 is the free-space wavelength at 900 MHz).
63 citations
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TL;DR: In this article, a planar circular disc monopole has been demonstrated to provide an ultra wide 10 dB return loss bandwidth with satisfactory radiation properties, and the parameters which affect the performance of the antenna in terms of its frequency domain characteristics are investigated.
Abstract: This paper presents a study of a novel monopole antenna for ultrawide-band (UWB) applications. Printed on a dielectric substrate and fed by a 50 /spl Omega/ microstrip line, a planar circular disc monopole has been demonstrated to provide an ultra wide 10 dB return loss bandwidth with satisfactory radiation properties. The parameters which affect the performance of the antenna in terms of its frequency domain characteristics are investigated. A good agreement is achieved between the simulation and the experiment. In addition, the time domain performance of the proposed antenna is also evaluated in simulations.
948 citations
TL;DR: In this paper, a small printed antenna with a reduced groundplane effect for ultrawideband (UWB) applications is described, where a notch is cut from the radiator while a strip is asymmetrically attached to the radiator.
Abstract: A small printed antenna is described with a reduced ground-plane effect for ultrawideband (UWB) applications. The radiator and ground plane of the antenna are etched onto a piece of printed circuit board (PCB) with an overall size of 25mmtimes25 mmtimes1.5 mm. A notch is cut from the radiator while a strip is asymmetrically attached to the radiator. The simulation and measurement show that the miniaturized antenna achieves a broad operating bandwidth of 2.9-11.6 GHz for a 10-dB return loss. In particular, the ground-plane effect on impedance performance is greatly reduced by cutting the notch from the radiator because the electric currents on the ground plane are significantly suppressed at the lower edge operating frequencies. The antenna features three-dimensional omni-directional radiation with high radiation efficiency of 79%-95% across the UWB bandwidth. In addition, a parametric study of the geometric and electric parameters of the proposed antenna will be able to provide antenna engineers with more design information
420 citations
TL;DR: The planar monopole antenna is shown to provide extremely wideband impedance characteristics and the radiation performance is also shown to be acceptable over a wide frequency range.
Abstract: The planar monopole antenna is shown to provide extremely wideband impedance characteristics. Recently, many techniques to tailor and optimize the impedance bandwidth of these antennas have been investigated. These include the use of bevels, slots and shorting posts. These antennas are becoming popular, and have been proposed for modern and future wideband wireless applications. The radiation performance is also shown to be acceptable over a wide frequency range.
382 citations
TL;DR: The planar inverted cone antenna (PICA) as mentioned in this paper provides ultrawideband (UWB) performance with a radiation pattern similar to monopole disk antennas, but is smaller in size.
Abstract: A new antenna, the planar inverted cone antenna (PICA), provides ultrawideband (UWB) performance with a radiation pattern similar to monopole disk antennas , but is smaller in size. Extensive simulations and experiments demonstrate that the PICA antenna provides more than a 10:1 impedance bandwidth (for VSWR<2) and supports a monopole type omnidirectional pattern over 4:1 bandwidth. A second version of the PICA with two circular holes changes the current flow on the metal disk and extends the high end of the operating frequency range, improving the pattern bandwidth to 7:1.
319 citations
TL;DR: Measured return loss and radiation pattern characteristics of textile UWB antennas agree well with simulations and measured transfer functions show that these textile antennas possess excellent transient characteristics, when operating in free space as well as on the human body.
Abstract: A new ultrawideband (UWB) textile antenna designed for UWB wireless body area network (WBAN) applications is presented. Unlike previous textile antennas, these antennas offer a direct integration into clothing due to a very small thickness (0.5 mm) and flexibility. We have realized two different designs of textile antennas: coplanar waveguide fed printed UWB disc monopole and UWB annular slot antenna. To our knowledge, these are the first textile UWB antennas reported in the open literature. Measured return loss and radiation pattern characteristics of textile UWB antennas agree well with simulations. Moreover, measured transfer functions show that these textile antennas possess excellent transient characteristics, when operating in free space as well as on the human body. They can operate in the entire UWB band approved by the Federal Communications Commission (3.1-10.6 GHz)
317 citations