SMALL-SIZE PRINTED STRIP MIMO ANTENNA FOR NEXT GENERATION MOBILE HANDSET APPLICATION

Abstract

A compact printed multiple-input multiple-output (MIMO) antenna with an embedded chip inductor is proposed for a 4G mobile handset application. The proposed MIMO antenna consists of a longer strip with an embedded chip inductor and a shorter radiating strip. The longer radiating strip with a 15-nH embedded chip inductor has a length of only about 42 mm (similar to 0.1 wavelength at 0.77 GHz), but it supports a wide resonant mode at 0.77 GHz for long-term evolution (LTE) Band 13 and at 2.35 GHz for WiBro operation. The shorter radiating strip has a length of about 15 mm (about 0.1 wavelength at 2.0 GHz) and provides a wide resonant mode at about 2 GHz for WCDMA operation. The two radiating strips occupy a small printed area of about 720 mm(2) on the system circuit board of a mobile handset. The proposed MIMO antenna has an isolation of approximately -17 dB at LTE band 13 and the envelope correlation coefficient (ECC) of the two antennas is always lower than 0.4 over the whole LTE band 13. To evaluate the performance of the proposed antenna, key performance parameters such as the total efficiency, ECC, mean effective gain (MEG), and the MEG ratio are analyzed.