Compact MIMO Antenna for Portable Devices in UWB Applications

• Published in: IEEE transactions on antennas and propagation Vol. 61; no. 8; pp. 4257 - 4264
• Main Authors: Li Liu, Cheung, S. W., Yuk, T. I.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.08.2013; Institute of Electrical and Electronics Engineers
• Subjects: Antenna measurements; Antennas; Applied sciences; Bandwidth; Exact sciences and technology; Impedance; MIMO; Multiple-input-multiple-output (MIMO) antenna; Mutual coupling; pattern diversity; planar monopole; Radiocommunications; Telecommunications; Telecommunications and information theory; Ultra wideband antennas; ultrawideband (UWB); Correlation coefficient; Performance evaluation; MIMO system; Mutual coupling; pattern diversity; ultrawideband (UWB); planar monopole; Ultra wide band; Multiple-input-multiple-output (MIMO) antenna; Frequency band; Simulation; Monopole antenna; Portable equipment; Radiation pattern; Plane antenna; Reflectance; Planar technology
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2013.2263277

A compact multiple-input-multiple-output (MIMO) antenna with a small size of 26×40 mm 2 is proposed for portable ultrawideband (UWB) applications. The antenna consists of two planar-monopole (PM) antenna elements with microstrip-fed printed on one side of the substrate and placed perpendicularly to each other to achieve good isolation. To enhance isolation and increase impedance bandwidth, two long protruding ground stubs are added to the ground plane on the other side and a short ground strip is used to connect the ground planes of the two PMs together to form a common ground. Simulation and measurement are used to study the antenna performance in terms of reflection coefficients at the two input ports, coupling between the two input ports, radiation pattern, realized peak gain, efficiency and envelope correlation coefficient for pattern diversity. Results show that the MIMO antenna has an impedance bandwidth of larger than 3.1-10.6 GHz, low mutual coupling of less than -15 dB, and a low envelope correlation coefficient of less than 0.2 across the frequency band, making it a good candidate for portable UWB applications.