A Review Paper on Stacked Microstrip Antenna for MIMO Application

Page 1

Volume 2, Spl. Issue 2 (2015)

e-ISSN: 1694-2310 | p-ISSN: 1694-2426

A Review Paper on Stacked Microstrip Antenna for MIMO Application Ayushi Agarwal1, Amanpreet Kaur2 1,2

ECE department, Thapar University, Patiala

1

aaayushi562@gmail.com, 2amanpreet.kaur@thapar.edu

Abstract---- MIMO system consists of multiple number of antennas at transmitter and receiver which in turn offers high capacity to wireless system over a SISO system. The stacked microstrip antenna has particular characteristics such as high gain and wide bandwidth which make it suitable for MIMO applications. This paper presents study on the stacked microstrip antenna and the parameters governing its operation. The application of stacked antenna to WLAN is also presented in the paper. Methods to obtain circular polarisation with rectangular patches are also presented in the current article. Keywords----Microstrip antenna, stacked, widebandwidth, high gain, high capacity, MIMO system, WLAN.

I. INTRODUCTION The idea of microstrip antenna dates back to 1950’s, but it was 1970’s in which microstrip antenna received considerable attention [1]. The basic configuration of microstrip antenna consists of a metallic patch printed on a thin ground dielectric substrate as shown in fig(1). The radiating element and the feed lines are usually photo etched on the dielectric substrate. The radiating patch may be square, rectangle, circle, thin strip(dipole) and many other configurations. There are many configurations that can be used to feed the antenna. The four most popular are the microstrip line, coaxial probe, aperture coupling, proximity coupling[1]. The microstrip patch is designed so that by excitation beneath the patch its pattern maximum is normal to the patch. The microstrip antenna is a broadside antenna. The microstrip antenna has a very low profile and can be made conformable and potentially at low cost. Other advantages include versatility in terms of electromagnetic induction [2] and easy fabrication into linear and planar array [3]. Although conventional microstrip antenna has various advantages but there are three main disadvantages associated with it namely their capability to resonate at single frequency, narrow bandwidth and low gain. This can be overcome by increasing thesubstrate height or alternatively stacking different layers to form a stacked antenna. But increasing the substrate height introduces the surface waves [1]. Therefore stacking is preferable [4] [5].

Fig 1. Microstrip antenna Development of wireless technology has raised the capacity and reliability requirements of wireless communication. It has become increasingly difficult to fulfil the requirements with traditional SISO systems due to the limitation in channel capacity. MIMO is a new wireless technology conveyed in mid 90s. One of the main benefits of MIMO is that the additional paths can be used to increase the capacity of the link without increasing transmitpower [6]. MIMO is able to transmit multiple de-correlated signals with same power level, simultaneously through spatially parallel channel. For any MIMO application wide band antenna is desirable, hence we can use stacked antenna to achieve wide band in conjunction with MIMO systems. The space consumption of MIMO antennas is vital in applications such as access points, modems and end terminal equipment in WLAN system. When regularly spaced antenna elements are used in MIMO systems, the channel capacity and transmission quality is dependent on the distance between the array elements. For compactness in MIMO system pattern diversity, multimode diversityand polarization diversityin conjunction with space diversity can be used. The paper presents a study on the use of stacked antennas for MIMO and WLAN applications and it is organised as follows. Section II gives the brief introduction of stacked microstrip antenna. Section III describes the various parameters associated with the stacked antenna. Next sections are dedicated towards the application of stacked antenna. Section IV presents a design strategy of stacked microstrip antenna for MIMO WLAN system. Section V deal with the analyses of the designed antenna. II.STACKED MICROSTRIP ANTENNA In spite of various advantages of microstrip antenna the bandwidth provided by the single patch antenna is narrow. It is well known that a multilayer structure is a useful method to improve the problem. In stacking a parasitic

BUEST, Baddi

RIEECE-2015

232


Turn static files into dynamic content formats.

Create a flipbook
Issuu converts static files into: digital portfolios, online yearbooks, online catalogs, digital photo albums and more. Sign up and create your flipbook.
A Review Paper on Stacked Microstrip Antenna for MIMO Application by IJEEE (Elixir Publications) - Issuu