Research Fellow - SFI Starting Investigator
Ph.D. in Electromagnetic Field & Microwave Theory (Southeast University, Jiangsu Province, China)
Room 410, Kevin Street Campus
Dr. Xiulong Bao is a Senior Research Associate with the School of Electronic and Communications Engineering at the Dublin Institute of Technology. He received the B.Sc. in Physics from the Huaibei Coal Industry Teachers’ College, Anhui Province, China in July 1991. He was awarded a M.Sc. in Physics and a Ph.D. in "Electromagnetic Field & Microwave Technology" from Southeast University, Nanjing, China in April 1996 and April 2003, respectively.
From 1996 to 1998, he was a lecturer with the Nanjing Forestry University’s School of Information and Science Technology, where he taught general physics and microwave engineering. As a senior researcher undertaking his Ph.D. at the Key State Laboratory for Millimeter Waves, Southeast University, Nanjing, he joined two National Natural Science Foundation of China projects; The “Investigation on the Antenna and Microwave Circuit based on Photonic Band Gap (PBG) Structure” and “Computation of the RCS for Large Irregular Objects using Generalized Multipole Technique (GMT)/ Physical Optics (PO) hybrid Method”. In addition, he contributed to an international Chinese-Singaporean project with Prof. Le-Wei Li, National University of Singapore on the “Investigation of the Basic Theory of a Complex Medium PBG Structure”. Dr. Bao proposed and implemented numerical calculations with a Pseudospectral Time-Domain (PSTD) method and a non-Yee Higher Order Finite Different Time Domain (FDTD) method to calculate the dispersion characteristics of the structure. His contributions produced more effective performance analyses of complex medium PBG structures while reducing computational resources and times by over 50%.
He joined the Shanghai Jiaotong University, Shanghai, China, as a Post-Doctoral Research Associate in 2003 to work on a Chinese 863 National Plan project on “Design of 35GHz Radar System Based on Monolithic Microwave Integrated Circuit Technology”. The project was in collaboration with the Shanghai Institute of Microsystem and Information Technology within the Chinese Academy of Sciences. He led the initial system design and was responsible for the design and delivery of a compact 2×2 and 4×4 element 35 GHz antenna array. The principle innovations related to size reduction with enhanced gain using via pins in close proximity to the resonant patches. In addition, he co-supervised two M.Sc. students on a circularly polarized antenna for the Chinese Satellite Positioning System and a compact dual-frequency handset PIFA antenna. The outcomes were subsequently exploited in commercial handheld applications by two Chinese companies.
In 2005, he joined Dr Max Ammann and the DIT’s Antenna and High Frequency Research Centre as a Research Associate. The €550,000 research program was part of the SFI CSET Centre for Telecommunications Value-Chain Research (CTVR) which is a campus-industry partnership that facilitated DIT’s provision of antennas to Trinity College Dublin and the National University of Ireland (Maynooth) in conjunction with Alcatel-Lucent Bell Labs Innovations (Ireland). He received the CTVR 2006 Achievement Award for his contributions to the design of miniaturized antennas for various wireless communications systems and he was promoted to Senior Research Associate in 2007.
His broad research interests include analysis and design of various small and circularly polarized antennas, such as GPS antennas, multiple-band antennas, RFID antennas, a DTV antenna, handset antennas, Ultra Wideband (UWB) antennas and the design and application of metamaterial/EBG structures. He is also active in the study of electromagnetic scattering, electromagnetic numerical computation (FDTD, PSTD, FDFD and MOM methods) and the study of electromagnetic wave propagation and antenna theory.
His main research interests include analysis and design of various small and circularly polarized antennas, such as GPS/handset antennas, multiple-band antennas, handset antennas, Ultra-Wideband (UWB) antennas and metamaterial/EBG structures. He is also active in electromagnetic scattering, electromagnetic numerical computation (such as FDTD, PSTD, FDFD and MOM methods), study on the propagation of electromagnetic waves and the theory of antennas.
He is currently working on projects:
(1) The Design of Annular-Ring Patch Antenna Loaded Circular Patch
The research employs modal manipulation on compact probe-fed annular-ring microstrip patch antennas by using strips in the radiating elements and cross-slots into the ground planes. The designs function efficiently with smaller size dimensions and are easily matched to 50 Ω. The antennas are designed for single band circular-polarization, dual-band circular polarization, triple band, and wideband operation.
(2) A Novel Rectangle Monopole UWB Antenna with Notch-Band Function
A printed monopole antenna employs a slotted-plate, which is electromagnetically-coupled to the microstrip-fed planar element, to provide a frequency band suppression. This technique enables improved control of stopband characteristics and provides a greater reduction in stop-band gain, compared to placing the slot in the microstrip feed section.
(3) Analysis and Design of Electromagnetic Band Gap Structure and Its Application
The analysis and design of compact and multiple-bandstop Electromagnetic Band Gap structures, such fractal and S-shaped high-impedance surfaces. A fractal high-impedance surface has been applied to a Global Positioning System (GPS) antenna to provide an enhanced polarisation axial ratio in the upper hemisphere and a significant gain improvement of 1.5dBi. S-shaped high-impedance surface is also employed in slot antennas to achieve unidirectional radiation and improve antenna gain.
(4) Design of the Wideband Circularly Polarized Dipole-like Antennas
The design of two types of wideband CP printed dipole antennas are carried out. One comprises an asymmetrical dipole and a slot which are fed by an L-shaped microstrip feedline using a via pin, other is consist of two unequal arms located in both sides of substrate and with a narrow slot in the groundplane. The proposed antennas can provide above 20% axial ratio bandwidth.
(5) Design of the Broad Beam Wave GPS antennas
Two techniques are used to achieve broad beamwidth: one is to extend substrate size and is applied on the dual-frequency GPS antenna; Other, by two layer patches on the both sides, the omnidirectional GPS antenna which fed by CPW feedline is achieved.
Dr. Bao is a Member of IEEE and was Technical Program Committee member for the 65th IEEE Vehicular Technology Conference, Dublin, 2007. He is also a peer reviewer for the IEEE Transactions on Antenna and Propagation, IEEE Transactions on Biomedical Engineering, IEEE Transactions on Information Technology in Biomedicine, and Journal of Electromagnetic Waves and Applications.
SFI best paper award at the 2009 China Ireland International Conference on Information & Communication Technologies for the paper titled Design of Compact Annular-Ring Patch Antennas for Circular Polarization.