Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 21 of 21
Full-Text Articles in Engineering
Improvement For Mimo Systems By Increasing Antenna Isolation And Shaping Radiation Pattern Using Hybrid Network, Min Li, Yujie Zhang, Fan Jiang, Di Wu, Kwan Lawrence Yeung, Lijun Jiang, Ross Murch
Improvement For Mimo Systems By Increasing Antenna Isolation And Shaping Radiation Pattern Using Hybrid Network, Min Li, Yujie Zhang, Fan Jiang, Di Wu, Kwan Lawrence Yeung, Lijun Jiang, Ross Murch
Electrical and Computer Engineering Faculty Research & Creative Works
In this article, a novel method is proposed to design a hybrid network (HN) to increase isolation and shape radiation patterns for multiple-input multiple-output (MIMO) antenna systems. The HN is a combination of a decoupling feeding network and a defected ground network, which are populated by several surface-mounted reactive components whose reactances are determined by the N-ary optimization algorithm. Two decoupling examples are presented to validate the design methodology and elaborate on the design procedure. Measurement results show that the HN helps to realize impedance matching with reflection coefficients below -10 dB, isolation improvement from -5.4/-8.9 dB to below -20 …
A Planar Low-Profile Meander Antenna Design For Wireless Terminal Achieving Low Rf Interference And High Isolation In Multi-Antenna Systems, Yang Xiao, Yihong Qi, Wei Yu, Ye Hai Bi, Xiangrui Su, Chunyu Wu, Qiang Liu, Jun Fan
A Planar Low-Profile Meander Antenna Design For Wireless Terminal Achieving Low Rf Interference And High Isolation In Multi-Antenna Systems, Yang Xiao, Yihong Qi, Wei Yu, Ye Hai Bi, Xiangrui Su, Chunyu Wu, Qiang Liu, Jun Fan
Electrical and Computer Engineering Faculty Research & Creative Works
In this article, a meander line internal antenna used for wireless terminal is proposed. The current of this antenna is mostly distributed on the antenna radiator itself, rather than on the main board of the wireless device. As a result, the chance of having radiofrequency (RF) interference issues, which usually result in receiver desensitization in wireless radios, can be significantly reduced. The antenna has good radiation performance in the vertical polarization with a low physical profile, compared with the existing antenna designs for typical wireless terminals. The antenna has efficiency similar to the monopole antenna with much less reference/ground plane …
Design Of Wideband Decoupling Networks For Mimo Antennas Based On An N-Ary Optimization Algorithm, Min Li, Kwan Lawrence Yeung, Lijun Jiang, Ross Murch
Design Of Wideband Decoupling Networks For Mimo Antennas Based On An N-Ary Optimization Algorithm, Min Li, Kwan Lawrence Yeung, Lijun Jiang, Ross Murch
Electrical and Computer Engineering Faculty Research & Creative Works
Techniques for reducing the coupling between antenna elements in multiple-input multiple-output (MIMO) systems are important for achieving the full potential of MIMO. In this article, a general and systematic method is developed to design a wideband decoupling and matching network (DMN) for MIMO antenna arrays. The DMN is formed by grid-like transmission lines interconnected by lumped components, whose reactance can be obtained from an N-ary optimization algorithm. Four design benchmarks are performed for validating decoupling methodology, elaborating on design/implementation procedure, and demonstrating superiority of the proposed method. Results show that the DMN achieves broad isolation bandwidth while occupying a small …
Novel Cma Scheme To Design Self-Decoupled Mimo Dipole Pair For Base-Station Applications, Min Li, Bing Xiao, Changfei Zhou, Di Wu, Kwan Lawrence Yeung, Lijun Jiang, Ross Murch
Novel Cma Scheme To Design Self-Decoupled Mimo Dipole Pair For Base-Station Applications, Min Li, Bing Xiao, Changfei Zhou, Di Wu, Kwan Lawrence Yeung, Lijun Jiang, Ross Murch
Electrical and Computer Engineering Faculty Research & Creative Works
This article presents a novel method to design multiple-input-multiple-output (MIMO) antennas based on characteristic mode analysis (CMA), which is different from using individual excitation of each characteristic mode for high isolation. The CMA is performed to design a pair of symmetric slots on two connected dipole antennas (a MIMO dipole pair), so that two desired characteristic modes can be generated at the same frequency, one of which is in common mode and the other in differential mode. Hence, when one antenna element is excited, the two characteristic modes combine and cancel each other at the other antenna element, leading to …
Decoupling And Matching Network For Dual-Band Mimo Antennas, Min Li, Yujie Zhang, Di Wu, Kwan Lawrence Yeung, Lijun Jiang, Ross Murch
Decoupling And Matching Network For Dual-Band Mimo Antennas, Min Li, Yujie Zhang, Di Wu, Kwan Lawrence Yeung, Lijun Jiang, Ross Murch
Electrical and Computer Engineering Faculty Research & Creative Works
This article presents a novel method to design the decoupling and matching network (DMN) for dual-band multi-input-multioutput (MIMO) antennas. The DMN consists of a grid of metallic microstrip stubs, some of which are connected while others are not. The connecting condition in the DMN is the only unknown variable for realizing high antenna isolation. It is determined by rigorous design formulas upon scattering matrix and optimized by the binary optimization algorithm, e.g., genetic algorithm (GA). Thus, high isolation among antennas can be achieved without requiring the optimization process in the electromagnetic simulation tool. Three decoupling examples of two two-element symmetric …
Dual-Band Decoupling Network For Mimo Antennas, Min Li, Lijun Jiang, Kwan Lawrence Yeung
Dual-Band Decoupling Network For Mimo Antennas, Min Li, Lijun Jiang, Kwan Lawrence Yeung
Electrical and Computer Engineering Faculty Research & Creative Works
This paper presents a novel method to design a decoupling network (DN) to increase isolation between dual-band antennas. The DN design is based on the scattering matrix and optimized by the Genetic Algorithm (GA). The decoupling example shows that the DN offers impedance matching and high isolation within desired bands, verifying the concept.
Isolation Enhancement For Mimo Patch Antennas Sharing A Common Thick Substrate: Using A Dielectric Block To Control Space-Wave Coupling To Cancel Surface-Wave Coupling, Min Li, Muhammad Yasir Jamal, Lijun Jiang, Kwan Lawrence Yeung
Isolation Enhancement For Mimo Patch Antennas Sharing A Common Thick Substrate: Using A Dielectric Block To Control Space-Wave Coupling To Cancel Surface-Wave Coupling, Min Li, Muhammad Yasir Jamal, Lijun Jiang, Kwan Lawrence Yeung
Electrical and Computer Engineering Faculty Research & Creative Works
This article presents a novel and simple decoupling method to increase the isolation between two closely spaced patch antennas sharing a common thick substrate. The decoupling can be simply realized by adding a pure dielectric block (DB) above the coupled array. By means of DB to modify the space permittivity (propagation constant), the space-wave coupling can be controlled to cancel surface-wave coupling for isolation enhancement. Five benchmarks of combinations of two patch antennas with different positions or orientations are investigated to validate the decoupling concept and elaborate on the design procedure. The results show that the proposed method could provide …
A Cascaded Power Dividing Decoupling Network For Antennas With Distinct Frequency Bands, Min Li, Lijun Jiang, Kwan Lawrence Yeung
A Cascaded Power Dividing Decoupling Network For Antennas With Distinct Frequency Bands, Min Li, Lijun Jiang, Kwan Lawrence Yeung
Electrical and Computer Engineering Faculty Research & Creative Works
This paper proposes a novel decoupling method for two antennas operating in adjacent/contiguous frequency bands using a cascaded power dividing decoupling network (C- PDDN). An n-order C-PDDN can be designed to increase antenna isolation at n desired frequency points. Each PDDN is composed of two power dividers, two transmission lines, and one reactive component. Explicit design formulas are founded for determining design parameters. For illustration, a two-order C- PDDN is applied to a testing array. Results show that it could increase isolation by over 20 dB, verifying the effectiveness.
Decoupling Of Antennas With Adjacent Frequency Bands Using Cascaded Decoupling Network, Min Li, Min Wang, Lijun Jiang, Lawrence Kwan Yeung
Decoupling Of Antennas With Adjacent Frequency Bands Using Cascaded Decoupling Network, Min Li, Min Wang, Lijun Jiang, Lawrence Kwan Yeung
Electrical and Computer Engineering Faculty Research & Creative Works
This communication presents a novel decoupling device called a cascaded power dividing decoupling network (C-PDDN). It is cascaded with two antennas operating in adjacent or even contiguous frequency bands to reduce the mutual coupling. To achieve high isolations at n desired frequency points, an n -order C-PDDN can be accordingly designed. Each order PDDN consists of two power dividers (PDs), two sections of transmission lines, and one reactive component. Explicit design formulas are presented to calculate the design parameters of the C-PDDN to meet the required isolation criteria. To validate the decoupling concept, a two-order C-PDDN is designed and applied …
Decoupling Of Antennas With Adjacent Frequency Bands, Min Li, Lijun Jiang, Lawrence Kwan Yeung
Decoupling Of Antennas With Adjacent Frequency Bands, Min Li, Lijun Jiang, Lawrence Kwan Yeung
Electrical and Computer Engineering Faculty Research & Creative Works
A decoupling device called cascaded power dividing decoupling network (C-PDDN) is presented for two antennas operating in adjacent frequency bands. Design formulas are derived to determine parametrical variables for high isolation. A prototype of a testing array consisting of two base-station dipole antennas is realized on a Rogers PCB for demonstration purposes. Simulated and experimental results show that good impedance matching, and high isolation are achieved simultaneously after adopting the C-PDDN.
Applying Power Dividers To Decoupling Of Mimo Antennas With Wideband, Dual-Band Or Adjacent-Band Operations, Min Li, Lijun Jiang, Kwan Lawrence Yeung
Applying Power Dividers To Decoupling Of Mimo Antennas With Wideband, Dual-Band Or Adjacent-Band Operations, Min Li, Lijun Jiang, Kwan Lawrence Yeung
Electrical and Computer Engineering Faculty Research & Creative Works
This paper presents a novel decoupling method of applying power dividers to isolation enhancement of multiple-input multiple-output antennas with wideband, dual-band, or adjacent-band operations. The decoupling structure consists of the power dividers, transmission lines, and reactive components. Three benchmarks are used to elaborate on the design procedure and demonstrate the advantages of the proposed method. Results show that this method offers good impedance matching and high port isolation at the designated frequencies.
A Novel Dual-Band Decoupling Technique, Min Li, Jamal Muhammad Yasir, Kwan Lawrence Yeung, Lijun Jiang
A Novel Dual-Band Decoupling Technique, Min Li, Jamal Muhammad Yasir, Kwan Lawrence Yeung, Lijun Jiang
Electrical and Computer Engineering Faculty Research & Creative Works
This article presents a novel dual-band decoupling network (DN) to increase the isolation between two antennas. It is composed of two dual-band Wilkinson power dividers, four additional transmission lines (TLs), and two reactive components. The decoupling formulas are derived from systematic design procedures. Hence, the design parameters of the power divider, lengths of TLs, and reactance of reactive components can be precisely determined to realize high port isolation. Two benchmarks of the two-element symmetric and asymmetric monopole arrays are used to elaborate the design procedure and demonstrate the advantages of proposed DN. Results show that the proposed DN can offer …
A Novel Wideband Decoupling Network For Two Antennas Based On The Wilkinson Power Divider, Min Li, Lijun Jiang, Kwan Lawrence Yeung
A Novel Wideband Decoupling Network For Two Antennas Based On The Wilkinson Power Divider, Min Li, Lijun Jiang, Kwan Lawrence Yeung
Electrical and Computer Engineering Faculty Research & Creative Works
In this article, a wideband decoupling network (DN) is presented based on the Wilkinson power divider (WPD). The DN is composed of 2 two-way unequal WPDs, three transmission lines (TLs), and two reactive components. Two techniques are introduced for the wideband performance: 1) by using the WPD with high output isolation, the antenna matching becomes independent of antenna decoupling. So, the decoupled antennas with the proposed DN could perform broad impedance bandwidths without using matching networks and 2) the DN is designed to minimize antennas' coupling coefficients at two frequencies, which collectively contribute to a broader decoupling bandwidth. In addition, …
A General And Systematic Method To Design Neutralization Lines For Isolation Enhancement In Mimo Antenna Arrays, Min Li, Lijun Jiang, Kwan Lawrence Yeung
A General And Systematic Method To Design Neutralization Lines For Isolation Enhancement In Mimo Antenna Arrays, Min Li, Lijun Jiang, Kwan Lawrence Yeung
Electrical and Computer Engineering Faculty Research & Creative Works
A general and systematic approach is the first time proposed in this paper to design the neutralization line (NL) for isolation enhancement in multiple-input multiple-output (MIMO) antenna arrays. Each NL consists of a metal strip and a reactive component attached at its middle position. It is connected with every two antenna radiators to generate an additional coupling path against the original antenna coupling for isolation enhancement. A general network model that leads to a systematic design procedure is developed to meet the required isolation criteria. Three practical examples are presented and used to verify the proposed NL-based decoupling technique (DT). …
A Miniaturized Dual-Band Dual-Polarized Band-Notched Slot Antenna Array With High Isolation For Base Station Applications, Min Li, Rong Wang, Jamal Muhammad Yasir, Lijun Jiang
A Miniaturized Dual-Band Dual-Polarized Band-Notched Slot Antenna Array With High Isolation For Base Station Applications, Min Li, Rong Wang, Jamal Muhammad Yasir, Lijun Jiang
Electrical and Computer Engineering Faculty Research & Creative Works
In this article, a miniaturized dual-band dual-polarized slot antenna array is proposed for base station applications. It consists of two closely located $1\times 4$ subarrays for the digital cellular system (DCS) and wideband code division multiple access (WCDMA) operations. The band-notched slot antenna (BNSA) is designed and adopted as the subarray element with radiation-suppression characteristic at notch frequencies. The notch frequency for one subarray is designed at the center operating frequency of the other subarray. As a result, the radiation from DCS subarray could be effectively suppressed within the WCDMA band and vice versa, resulting in high isolation between two …
Novel And Efficient Parasitic Decoupling Network For Closely Coupled Antennas, Min Li, Lijun Jiang, Kwan Lawrence Yeung
Novel And Efficient Parasitic Decoupling Network For Closely Coupled Antennas, Min Li, Lijun Jiang, Kwan Lawrence Yeung
Electrical and Computer Engineering Faculty Research & Creative Works
A novel and efficient parasitic decoupling network (PDN) is proposed for closely coupled antennas in this paper, which provides a new perspective and approach to design DNs based on the parasitic decoupling concept. The PDN is composed of sections of transmission lines (TLs) and reactive components, allowing additional power-traveling paths. With the TL lengths and reactive component reactance being precisely determined, the traveling power from one antenna to another could cancel out the undesired power wave induced by mutual coupling, resulting in the high port isolation. The decoupling theory is rigorously derived with the design procedure of the PDN systematically …
The Decoupling Methods For Increasing The Isolation Between Two Antennas, Min Li, Lijun Jiang
The Decoupling Methods For Increasing The Isolation Between Two Antennas, Min Li, Lijun Jiang
Electrical and Computer Engineering Faculty Research & Creative Works
This paper presented the parasitic structure decoupling method and other related approaches to increase the isolation between two closely coupled antennas. The design parameters of the resultant decoupling structures based on the proposed methods can be precisely derived instead of fitted to achieve high antenna isolations. A two-element monopole array is employed as a benchmark to demonstrate the effectiveness of the proposed methods. The simulation results show that good impedance matching and high port isolation could be achieved simultaneously based on the proposed methods.
A Compact Dual-Frequency Base-Station Dipole Array With Amc Reflector, Min Li, Lijun Jiang
A Compact Dual-Frequency Base-Station Dipole Array With Amc Reflector, Min Li, Lijun Jiang
Electrical and Computer Engineering Faculty Research & Creative Works
A compact dual-frequency dipole array is presented for use in base stations operating in the Digital Cellular System (DCS) and Wideband Code Division Multiple Access (WCDMA) bands. The size-miniaturization is realized by utilizing band notch dipole (BND) as array element and artificial magnetic conductor (AMC) as array reflector for reductions in array width and profile height, respectively. Simulation results show that good impedance matching, high antenna isolation, and good radiation performances are achieved simultaneously.
Decoupling Of Multi-Element Mimo Antennas, Min Li, L. (Lijun) J. Jiang
Decoupling Of Multi-Element Mimo Antennas, Min Li, L. (Lijun) J. Jiang
Electrical and Computer Engineering Faculty Research & Creative Works
An efficient decoupling technique for multi-element MIMO antennas is proposed in this paper. A general model of using parasitic decoupling structure (PDS) to satisfy the criterions derived from antenna impedances for perfect isolation is presented. A prototype of three monopole antennas is realized on a Rogers PCB for demonstration purpose. The simulation results show that good impedance matching and high port isolation are achieved simultaneously.
Traces In Proximity To Gaps In Return Planes, Todd H. Hubing, Thomas Van Doren, Theodore M. Zeeff
Traces In Proximity To Gaps In Return Planes, Todd H. Hubing, Thomas Van Doren, Theodore M. Zeeff
Electrical and Computer Engineering Faculty Research & Creative Works
Coupling between circuitry on printed circuit boards can be mitigated by a variety of well-known techniques. One such technique is to isolate circuitry in different areas of the printed circuit board by strategically placing a gap in the signal return plane. However, this technique is only effective at reducing common-impedance coupling, which is generally not a significant coupling mechanism at frequencies above 1 MHz. This paper investigates the effect of a gap located between and parallel to adjacent microstrip traces. The effect of the gap on the mutual inductance and mutual capacitance is evaluated. Laboratory measurements and numerical simulations show …
A Circuit Approach To Model Narrow Slot Structures In A Power Bus, Lin Zhang, Ray Alexander, Richard E. Dubroff, James L. Drewniak, James L. Knighten, Norman W. Smith, Bruce Archambeault, Samuel R. Connor, Jun Fan
A Circuit Approach To Model Narrow Slot Structures In A Power Bus, Lin Zhang, Ray Alexander, Richard E. Dubroff, James L. Drewniak, James L. Knighten, Norman W. Smith, Bruce Archambeault, Samuel R. Connor, Jun Fan
Electrical and Computer Engineering Faculty Research & Creative Works
A coupled transmission line model for narrow slot structures in DC power planes is proposed. This approach, combined with SPICE-based cavity models and a segmentation method, provides an easy and fast way to model relatively complex structures of power planes with narrow slots often used for isolation purposes. This approach is used to achieve isolation using gapping. The cavity model formulations for rectangular and isosceles right triangular segments are reviewed. The rationale of modeling the narrow slot as a three-conductor transmission line is described. The modeling results are shown and compared with the output of a full wave simulation tool, …