Xidong Wu - Academia.edu (original) (raw)
Papers by Xidong Wu
Materials Science and Engineering: C, 2016
IEEE Antennas and Propagation Society International Symposium. Transmitting Waves of Progress to the Next Millennium. 2000 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.00CH37118), 2000
ABSTRACT
2014 ISFMFE - 6th International Symposium on Fluid Machinery and Fluid Engineering, 2014
2014 IEEE MTT-S International Microwave Symposium (IMS2014), 2014
This paper presents a simple-layout antipodal finline structure integrated in a standard WR-28 wa... more This paper presents a simple-layout antipodal finline structure integrated in a standard WR-28 waveguide, also with the advantages of low insertion loss and broad band width. There are only four parameters in total which can define a unique layout; the influences of these factors on the performance is simulated with CST Microwave Studio and discussed in this paper. This paper offers a clear and simple design procedure for antipodal finline, which also has high fabrication tolerance besides the excellent performance. I. INTRODUCTION Mm-wave combines the advantages of microwave and infrared, because its wavelength is sandwiched between theirs. Along with the rapid development of microwave and mm-wave hybrid and monolithic integrated circuits, the transition between waveguide and microstrip plays a more and more important role in the performance of circuits. So there is an increasing demand for waveguide-to-microstrip transition which is of broad band width and low insertion loss. Of c...
This paper proposed a 360° azimuth scanning cylindrical dielectric lens antenna at mm-waves. The ... more This paper proposed a 360° azimuth scanning cylindrical dielectric lens antenna at mm-waves. The antenna system consists of Rexolite (ϵr=2.54) cylindrical lens, tapered slot antenna (TSA) array and circular parallel conductor plates. A combined ray-optics method and CST-MWS are used to analyze and optimize this cylindrical dielectric lens antenna at 30GHz. A total of 60 TSAs are used to launch 60 beams, each with 3dB beamwidth of 6° leading to a 360° scan coverage.
Progress In Electromagnetics Research Letters, 2012
This paper presents a tri-band Wilkinson power divider. The proposed structure is derived from th... more This paper presents a tri-band Wilkinson power divider. The proposed structure is derived from the conventional Wilkinson power divider by replacing the quarter-wavelength branch lines with the extended T-shaped short or open stubs. The first and the third operating frequencies of the proposed power divider can be flexibly controlled, while the second frequency is equal to the mean value of the other two frequencies. Both the power dividers using the extended T-shaped short and open stub structures are designed based on the derived equations and the frequency response characteristics are discussed. For verification, a short stub based tri-band Wilkinson power divider operating at 1.3, 3.0 and 4.7 GHz is fabricated and measured. The measurements are in good agreement with the simulations. The measured bandwidths of -20 dB isolation are 1.22 - 1.42 GHz, 2.92 - 3.18 GHz and 4.66 - 4.86 GHz, respectively. Over these three operating bandwidths, the measured return losses are better than ...
A new design of lens antenna at millimeter-wave frequencies is introduced with special focus on e... more A new design of lens antenna at millimeter-wave frequencies is introduced with special focus on ease of manufacturing and reliability. The system is composed of a modified Luneberg cylindrical lens and a feed antenna. The modified Luneberg cylindrical lens consists of two parallel plates with the space between plates only filled with air, thus free of dielectric loss. A planar linear tapered slot antenna (LTSA) is inserted into the air region between the parallel plates at the edge of the lens as a feed antenna. A combined ray-optics method and CST-MWS are used to analyze and design this cylindrical lens antenna at 30 GHz. Due to its spherical symmetry, the proposed lens can be used to launch multiple beams by implementing an arc array of planar LTSA elements at the periphery of the lens. The proposed antenna can be easily extended for higher mm-wave frequencies, and is well suitable for scanning fan-beam applications, such as aircraft landing systems.
2010 IEEE Antennas and Propagation Society International Symposium, 2010
31st European Microwave Conference, 2001, 2001
... Bernhard Schoenlinner and Gabriel Rebeiz are with the Radiation Laboratory, Department of Ele... more ... Bernhard Schoenlinner and Gabriel Rebeiz are with the Radiation Laboratory, Department of Electrical Engineering and Computer Sci-ence, University of ... measured using the standard-gain technique (with a calibrated transmitting horn an-tenna) and using the Friis formula. ...
2012 IEEE/MTT-S International Microwave Symposium Digest, 2012
ABSTRACT A new cylindrical modified Luneberg lens antenna at millimeter-wave frequencies is desig... more ABSTRACT A new cylindrical modified Luneberg lens antenna at millimeter-wave frequencies is designed using parallel plate techniques. The cylindrical modified Luneberg lens consists of two parallel plates which are filled with air. The plates spacing is continuously varied with the normalized radius to achieve a general Luneberg's variation of the effective index of refraction. A planar antipodal linearly-tapered slot antenna (ALTSA) is placed between the parallel plates at the focal position of the lens as a feed antenna. A ray-tracing method and CST-MWS are used to analyze and design this cylindrical lens antenna at 30 GHz. Measurements show good agreement with the simulations.
IEEE Antennas and Propagation Society Symposium, 2004., 2004
The wide angle scanning antenna is essential for many mm-wave applications such as broadband wire... more The wide angle scanning antenna is essential for many mm-wave applications such as broadband wireless communications, automobile radars and imaging radars. An excellent design is given in Schoenlinner et al. (2002) using a simple spherical lens antenna to launch 33 pencil-beams to achieve 180° scan coverage. This paper extends this design concept to launch scanning fan-beams by using cylindrical lens between two parallel conductor plates. The measurement agrees very well with the simulations, and a gain of 16.5 dB with E- and H-plane beamwidth of 6.0° and 60° is achieved at 30 GHz. The designed antenna can be easily extended to 94 GHz, and is well suited for either single or scanning fan-beam applications, such as aircraft landing systems.
2008 IEEE Antennas and Propagation Society International Symposium, 2008
ABSTRACT This paper demonstrated a broadband power combiner using hyperbolic thin lens inside a r... more ABSTRACT This paper demonstrated a broadband power combiner using hyperbolic thin lens inside a rectangular waveguide. Simulation results show that combining efficiencies of 61% - 92% can be achieved across the entire Ka-band. More results will be discussed on the conference.
2010 IEEE Antennas and Propagation Society International Symposium, 2010
ABSTRACT In this paper, a novel dual-band Wilkinson power divider with 6:1 power dividing ratio i... more ABSTRACT In this paper, a novel dual-band Wilkinson power divider with 6:1 power dividing ratio is presented. For this purpose, two sections of coupled lines terminated with shorted stub are employed to replace the quarter-wavelength transmission lines in the classical single-band unequal Wilkinson power divider. Based on the evenodd analysis, the design equations are given. As an example, a dual-band Wilkinson power divider with 6:1 power dividing ratio is designed at 1.0 GHz and 1.8 GHz.
Progress In Electromagnetics Research, 2011
ABSTRACT This paper presents dual-band equal/unequal Wilkinson power dividers based on a coupled-... more ABSTRACT This paper presents dual-band equal/unequal Wilkinson power dividers based on a coupled-line section with short-circuited stub (called as the "coupled-line section" for short), which consists of a pair of parallel coupled lines and a short-circuited stub. With the analyses of the phase shift and equivalent characteristic impedance, the coupled-line section is used to replace the quarter-wavelength branch line in the conventional equal/unequal Wilkinson power divider to obtain excellent dual-band operation. The closed-form equations and design procedures of dual-band Wilkinson power divider are given, where one degree of design freedom is obtained and design flexibility is shown. As two examples, a dual-band equal Wilkinson power divider with the frequency ratio of 1.8 : 1 and an unequal one with the high power dividing ratio of 7 : 1 and frequency ratio of 1.8 : 1 are designed, fabricated and measured. The measurements are in good agreement with the simulations. It is shown that the proposed power dividers have simple topologies, and can be easily fabricated with small frequency ratios and high power dividing ratios.
2010 IEEE Antennas and Propagation Society International Symposium, 2010
ABSTRACT This paper demonstrated a novel kind of two-dimensional elliptical lens antenna for mono... more ABSTRACT This paper demonstrated a novel kind of two-dimensional elliptical lens antenna for monopulse applications. Simulations show that the lens antenna exhibits a very clean and symmetrical pattern on both the sum and different ports. A very deep null is achieved in the difference pattern because of the circuit symmetry.
Progress In Electromagnetics Research Letters, 2010
2009 Asia Pacific Microwave Conference, 2009
ABSTRACT This paper presents a defected-ground coupled line section with two shorts (DGCL section... more ABSTRACT This paper presents a defected-ground coupled line section with two shorts (DGCL section) which consists of an offset dumb-bell-shaped defected ground structure (DGS) at the back of edge-coupled lines. An equivalent circuit model is given based on even-odd mode analysis, which shows that the characteristic impedance of coupled line section can be lowered and bandwidth can be improved by introducing a DGS at the back. A wideband balun, which consists of a quarter-wavelength microstrip line and a DGCL section, is then designed, fabricated and measured. Measurements show that the return loss at the unbalance port is better than -10 dB from 3 GHz to 9 GHz. The amplitude imbalance and phase difference between the two balance ports are within 1 dB and 180° ± 9° over the operation bandwidth, respectively.
2009 Asia Pacific Microwave Conference, 2009
ABSTRACT A two-dimensional waveguide thin lens is presented for mm-wave quasi-optical power combi... more ABSTRACT A two-dimensional waveguide thin lens is presented for mm-wave quasi-optical power combining. The proposed waveguide lens can be realized by air-filled parallel plate waveguides, thus free of dielectric loss. A ten-way power combiner using waveguide meniscus thin lens is given as a design example at 30 GHz. Simulations show the designed waveguide meniscus lens can achieve combining efficiencies of more than 93.2% across the entire Ka-band.
Materials Science and Engineering: C, 2016
IEEE Antennas and Propagation Society International Symposium. Transmitting Waves of Progress to the Next Millennium. 2000 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.00CH37118), 2000
ABSTRACT
2014 ISFMFE - 6th International Symposium on Fluid Machinery and Fluid Engineering, 2014
2014 IEEE MTT-S International Microwave Symposium (IMS2014), 2014
This paper presents a simple-layout antipodal finline structure integrated in a standard WR-28 wa... more This paper presents a simple-layout antipodal finline structure integrated in a standard WR-28 waveguide, also with the advantages of low insertion loss and broad band width. There are only four parameters in total which can define a unique layout; the influences of these factors on the performance is simulated with CST Microwave Studio and discussed in this paper. This paper offers a clear and simple design procedure for antipodal finline, which also has high fabrication tolerance besides the excellent performance. I. INTRODUCTION Mm-wave combines the advantages of microwave and infrared, because its wavelength is sandwiched between theirs. Along with the rapid development of microwave and mm-wave hybrid and monolithic integrated circuits, the transition between waveguide and microstrip plays a more and more important role in the performance of circuits. So there is an increasing demand for waveguide-to-microstrip transition which is of broad band width and low insertion loss. Of c...
This paper proposed a 360° azimuth scanning cylindrical dielectric lens antenna at mm-waves. The ... more This paper proposed a 360° azimuth scanning cylindrical dielectric lens antenna at mm-waves. The antenna system consists of Rexolite (ϵr=2.54) cylindrical lens, tapered slot antenna (TSA) array and circular parallel conductor plates. A combined ray-optics method and CST-MWS are used to analyze and optimize this cylindrical dielectric lens antenna at 30GHz. A total of 60 TSAs are used to launch 60 beams, each with 3dB beamwidth of 6° leading to a 360° scan coverage.
Progress In Electromagnetics Research Letters, 2012
This paper presents a tri-band Wilkinson power divider. The proposed structure is derived from th... more This paper presents a tri-band Wilkinson power divider. The proposed structure is derived from the conventional Wilkinson power divider by replacing the quarter-wavelength branch lines with the extended T-shaped short or open stubs. The first and the third operating frequencies of the proposed power divider can be flexibly controlled, while the second frequency is equal to the mean value of the other two frequencies. Both the power dividers using the extended T-shaped short and open stub structures are designed based on the derived equations and the frequency response characteristics are discussed. For verification, a short stub based tri-band Wilkinson power divider operating at 1.3, 3.0 and 4.7 GHz is fabricated and measured. The measurements are in good agreement with the simulations. The measured bandwidths of -20 dB isolation are 1.22 - 1.42 GHz, 2.92 - 3.18 GHz and 4.66 - 4.86 GHz, respectively. Over these three operating bandwidths, the measured return losses are better than ...
A new design of lens antenna at millimeter-wave frequencies is introduced with special focus on e... more A new design of lens antenna at millimeter-wave frequencies is introduced with special focus on ease of manufacturing and reliability. The system is composed of a modified Luneberg cylindrical lens and a feed antenna. The modified Luneberg cylindrical lens consists of two parallel plates with the space between plates only filled with air, thus free of dielectric loss. A planar linear tapered slot antenna (LTSA) is inserted into the air region between the parallel plates at the edge of the lens as a feed antenna. A combined ray-optics method and CST-MWS are used to analyze and design this cylindrical lens antenna at 30 GHz. Due to its spherical symmetry, the proposed lens can be used to launch multiple beams by implementing an arc array of planar LTSA elements at the periphery of the lens. The proposed antenna can be easily extended for higher mm-wave frequencies, and is well suitable for scanning fan-beam applications, such as aircraft landing systems.
2010 IEEE Antennas and Propagation Society International Symposium, 2010
31st European Microwave Conference, 2001, 2001
... Bernhard Schoenlinner and Gabriel Rebeiz are with the Radiation Laboratory, Department of Ele... more ... Bernhard Schoenlinner and Gabriel Rebeiz are with the Radiation Laboratory, Department of Electrical Engineering and Computer Sci-ence, University of ... measured using the standard-gain technique (with a calibrated transmitting horn an-tenna) and using the Friis formula. ...
2012 IEEE/MTT-S International Microwave Symposium Digest, 2012
ABSTRACT A new cylindrical modified Luneberg lens antenna at millimeter-wave frequencies is desig... more ABSTRACT A new cylindrical modified Luneberg lens antenna at millimeter-wave frequencies is designed using parallel plate techniques. The cylindrical modified Luneberg lens consists of two parallel plates which are filled with air. The plates spacing is continuously varied with the normalized radius to achieve a general Luneberg's variation of the effective index of refraction. A planar antipodal linearly-tapered slot antenna (ALTSA) is placed between the parallel plates at the focal position of the lens as a feed antenna. A ray-tracing method and CST-MWS are used to analyze and design this cylindrical lens antenna at 30 GHz. Measurements show good agreement with the simulations.
IEEE Antennas and Propagation Society Symposium, 2004., 2004
The wide angle scanning antenna is essential for many mm-wave applications such as broadband wire... more The wide angle scanning antenna is essential for many mm-wave applications such as broadband wireless communications, automobile radars and imaging radars. An excellent design is given in Schoenlinner et al. (2002) using a simple spherical lens antenna to launch 33 pencil-beams to achieve 180° scan coverage. This paper extends this design concept to launch scanning fan-beams by using cylindrical lens between two parallel conductor plates. The measurement agrees very well with the simulations, and a gain of 16.5 dB with E- and H-plane beamwidth of 6.0° and 60° is achieved at 30 GHz. The designed antenna can be easily extended to 94 GHz, and is well suited for either single or scanning fan-beam applications, such as aircraft landing systems.
2008 IEEE Antennas and Propagation Society International Symposium, 2008
ABSTRACT This paper demonstrated a broadband power combiner using hyperbolic thin lens inside a r... more ABSTRACT This paper demonstrated a broadband power combiner using hyperbolic thin lens inside a rectangular waveguide. Simulation results show that combining efficiencies of 61% - 92% can be achieved across the entire Ka-band. More results will be discussed on the conference.
2010 IEEE Antennas and Propagation Society International Symposium, 2010
ABSTRACT In this paper, a novel dual-band Wilkinson power divider with 6:1 power dividing ratio i... more ABSTRACT In this paper, a novel dual-band Wilkinson power divider with 6:1 power dividing ratio is presented. For this purpose, two sections of coupled lines terminated with shorted stub are employed to replace the quarter-wavelength transmission lines in the classical single-band unequal Wilkinson power divider. Based on the evenodd analysis, the design equations are given. As an example, a dual-band Wilkinson power divider with 6:1 power dividing ratio is designed at 1.0 GHz and 1.8 GHz.
Progress In Electromagnetics Research, 2011
ABSTRACT This paper presents dual-band equal/unequal Wilkinson power dividers based on a coupled-... more ABSTRACT This paper presents dual-band equal/unequal Wilkinson power dividers based on a coupled-line section with short-circuited stub (called as the "coupled-line section" for short), which consists of a pair of parallel coupled lines and a short-circuited stub. With the analyses of the phase shift and equivalent characteristic impedance, the coupled-line section is used to replace the quarter-wavelength branch line in the conventional equal/unequal Wilkinson power divider to obtain excellent dual-band operation. The closed-form equations and design procedures of dual-band Wilkinson power divider are given, where one degree of design freedom is obtained and design flexibility is shown. As two examples, a dual-band equal Wilkinson power divider with the frequency ratio of 1.8 : 1 and an unequal one with the high power dividing ratio of 7 : 1 and frequency ratio of 1.8 : 1 are designed, fabricated and measured. The measurements are in good agreement with the simulations. It is shown that the proposed power dividers have simple topologies, and can be easily fabricated with small frequency ratios and high power dividing ratios.
2010 IEEE Antennas and Propagation Society International Symposium, 2010
ABSTRACT This paper demonstrated a novel kind of two-dimensional elliptical lens antenna for mono... more ABSTRACT This paper demonstrated a novel kind of two-dimensional elliptical lens antenna for monopulse applications. Simulations show that the lens antenna exhibits a very clean and symmetrical pattern on both the sum and different ports. A very deep null is achieved in the difference pattern because of the circuit symmetry.
Progress In Electromagnetics Research Letters, 2010
2009 Asia Pacific Microwave Conference, 2009
ABSTRACT This paper presents a defected-ground coupled line section with two shorts (DGCL section... more ABSTRACT This paper presents a defected-ground coupled line section with two shorts (DGCL section) which consists of an offset dumb-bell-shaped defected ground structure (DGS) at the back of edge-coupled lines. An equivalent circuit model is given based on even-odd mode analysis, which shows that the characteristic impedance of coupled line section can be lowered and bandwidth can be improved by introducing a DGS at the back. A wideband balun, which consists of a quarter-wavelength microstrip line and a DGCL section, is then designed, fabricated and measured. Measurements show that the return loss at the unbalance port is better than -10 dB from 3 GHz to 9 GHz. The amplitude imbalance and phase difference between the two balance ports are within 1 dB and 180° ± 9° over the operation bandwidth, respectively.
2009 Asia Pacific Microwave Conference, 2009
ABSTRACT A two-dimensional waveguide thin lens is presented for mm-wave quasi-optical power combi... more ABSTRACT A two-dimensional waveguide thin lens is presented for mm-wave quasi-optical power combining. The proposed waveguide lens can be realized by air-filled parallel plate waveguides, thus free of dielectric loss. A ten-way power combiner using waveguide meniscus thin lens is given as a design example at 30 GHz. Simulations show the designed waveguide meniscus lens can achieve combining efficiencies of more than 93.2% across the entire Ka-band.