ESTI Specification Simplifies WiMAX Antenna Selection

Introduction

Lack of standards and spotty frequency availability in the sub-11 GHz region has forced many original equipment manufacturers (OEMs) and network operators to specify unique custom antennas for base stations and backhaul in broadband wireless point-to-mulipoint applications. While many of the resulting antenna designs have had merits, the lack of volume production and field testing has often resulted in expensive, unreliable products. With the continuing harmonization of the global frequency bands and some valuable work conducted by the European Telecommunications Standard Institute (ETSI), a set of high-performance broadband antennas that cover these harmonized frequency bands are quickly becoming the industry norm. This article clarifies the important aspects of WiMAX antenna requirements and provides representative WiMAX antenna models.

WiMAX Base Station Requirements Envelope

The general requirements that operators and OEMs are placing on antennas stem from their desire to maximize system performance at minimal cost. OEMs want antennas with specifications that apply to the widest possible set of applications. This can be realized by choosing antennas that meet the highest radiation specifications and have frequency bandwidths that extend over the entire global frequency band of interest. Operators, meanwhile, are interested in antennas that allow the maximum frequency reuse and have a small, unobtrusive form factor that allows for the maximum flexibility in antenna site acquisition. Both parties would like low-cost test antennas that are environmentally robust.