Design and Fabrication of an Electrically Small Meander Line MIMO Antenna System for Wireless Communication Applications

Abstract

A multiple-input multiple-output (MIMO) technique has been considered one of the most promising technologies to enhance the performance of wireless communication systems with high-speed transmission rates. A MIMO system utilizing several antenna components is more advantageous than a single-input single-output (SISO) system in terms of increasing channel capacity and reducing transmitting power. Conventional universal serial bus (USB) dongles are attractive for providing plug and- play functionality in mobile communication devices such as laptops. Future wireless USB dongles should be capable of accommodating higher data rates than the current systems owing to the advent of various multimedia services. Up to date, most MIMO antenna systems with more than two antennas are three-dimensional rather than planar. However, the basic problem with the MIMO systems is the requirement of electrically small antennas which usually have several constraints. Hence, these antennas are considered in our project work. In this work the design, optimization, fabrication & testing of electrically small antennas suitable for MIMO (multiple input multiple output) applications are presented. When the transceiver uses more than one antenna, the antennas must be placed at least half of the carrier wavelength apart, in order to transmit/receive uncorrelated signals. We propose an electrically small antenna (ESA) that is based on the meander line antenna structure that operates in the 2.4-2.7 GHz ISM band. The proposed antenna has measured center frequency of 2.50 GHz with 240 MHz bandwidth and total size of antenna is 14.5X26.6 mm. In addition, we present the design of a compact dual element MIMO antenna system for a USB dongle operating in the 2.5-2.7 GHz frequency band. Thedesigned MIMO antenna has the compact size of 26.0 mm×32.0 mm, more than 200 MHz bandwidth.Both simulation and experiment results from the fabricated antennas are presented.