A high‐isolation mimo antenna with dual‐feed structure for WiFi of mobile phones

• Published in: Microwave and optical technology letters Vol. 59; no. 4; pp. 930 - 934
• Main Authors: Lee, Won‐Woo, Cho, Yong‐Sang
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc 01-04-2017
• Subjects: antenna; Antennas; Correlation coefficients; Coupling; ECC; Feeding; Grounds; Lithosphere; Microwaves; MIMO; Ports; Radiators; WiFi
• ISSN: 0895-2477; 1098-2760
• DOI: 10.1002/mop.30427

ABSTRACT
In this letter, we develop a new Multiple‐Input Multiple‐Output (MIMO) antenna that has two independent signal feed‐points in a single antenna element. This antenna is composed of a cross‐coupled semi‐loop (CCSL) structure and an inverted‐F antenna (IFA) operating at 2.4–2.483 GHz and 5.15–5.85 GHz. The dual‐port structure is implemented by adding a CCSL antenna as the secondary radiator to the ground short of an IFA. To achieve isolation between the signal‐feeding ports of the antenna at the same operating frequency, a loop‐type coupling pattern is used to make the induced current flow orthogonal with respect to that of the other feeding port. The measured isolation performance between the feeding ports greater than 12 dB at 2.4 GHz and greater than15 dB at 5.5 GHz. We show that the proposed antenna has an Envelope Correlation Coefficient value as low as 0.3 at the 2.4 GHz band and as low as 0.1 at the 5.5 GHz band. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:930–934, 2017