Compact metamaterial antenna array for long term evolution (LTE) handset application

Abstract

In the digital world, Moore's Law states the number of transistors on Integrated Circuits (ICs) has been doubling every two years since 1965. While these ICs occupy only 10% of the wireless communication device area, the remaining 90%, referred to as RF Front-End Model (FEM), consists of a collection of discrete passive and active components such as antennas, filters, diplexer, duplexers, couplers, power combiner/splitter, and power amplifiers. While these powerful ICs enable effective implementation of Multiple Input Multiple Output (MIMO) digital processing, the main issue of MIMO RF FEM implementation in small devices such as handsets still remains unsolved. Without such a full solution, network providers cannot deploy next generation wireless broadband networks, such as 3GPP Long Term Evolution (LTE) networks, that can sustain tens of Mbps throughput with mobility. This paper addresses this specific problem by presenting an LTE MIMO air interface solution for handsets using metamaterial designs, which offer small, low-cost, and low-profile antennas printed directly on PCB for easy integration and simple manufacturing - all critical factors for rapid deployment and commercial success. The proposed metamaterial MIMO array consists of dual resonance antennas occupying λ0/10 × λ0/41 × λ0/387 volume at center frequency 771MHz of the LTE band 746–796MHz. The performances of two antenna array configurations with spacing of λ0/13 and λ0/5 are studied while quantifying its near-filed and far-field channel correlation.