Antenna Systems & Technology - Fall 2014 - (Page 16)

FEATURE ARTICLE Ensuring Consistent Connectivity for Mission-Critical Applications By Jeff Shamblin, Chief Scientist | Ethertronics If there's one sure bet in RF, it's that there isn't one. Every RF environment is unique, which is why it's so challenging to ensure a constant connection for mission-critical applications. GPS is a prime example. It's the foundation for a wide variety of consumer, business and government applications, including E-911, military, navigation and offender tracking. That means money and lives depend on the antenna system's ability to track satellites no matter what. GPS also is an example of why a one-size-fits-all design approach doesn't cut it for antennas used in mission-critical applications. Device OEMs that understand the reasons why, enjoy a competitive advantage not only in mission-critical verticals, but also in consumer applications where accuracy and reliability are market differentiators. And there are a lot of them. For example, check out app store reviews of fitness trackers and you'll find plenty of complaints when GPS accuracy is off even slightly. That's unacceptable to fitness buffs who care about every calorie and step. For military and other mission-critical applications, GPS accuracy and reliability can mean the difference between life and death. Here's what systems designers at device OEMs and other companies should put on their short list when selecting a GPS antenna: * An axial ratio of no more than 1.5 dB at zenith, and a minimum gain of -5 dB at zenith ensure maximum signal reception, Figure 1. * The ideal antenna should be no longer than 35 mm, especially if needs to be inside the device rather than external. That's roughly 25 percent shorter than most antennas on the market today, which highlights the challenge of getting it down to that size without performance trade-offs. When suppliers can meet the challenge, they (and their OEM customers) are uniquely positioned to meet the demand for increasingly compact mobile phones, walkie-talkies, tough books and other GPS enabled devices. * A small keep-out area enables more design flexibility because other components now can be closer to the antenna without creating interference and other problems that Figure 1. Axial Ratio would undermine reliability and accuracy. * The antenna should be tunable for multiple satcom frequencies and for both right and left-hand polarizations. This flexibility reduces development costs and lead-time because the same design can be used in multiple products. * Consistently high performance is key. For example, the antenna should be effectively immune to the detuning that frequently occurs due to environmental changes such as the user's head or hand, or a large truck pulled alongside the vehicle that needs 24/7/365 tracking. The antenna also should be able to make the most of the weak signal conditions that are common inside buildings, such as when tracking high-value assets. This reliability is a market differentiator for OEMs and thus minimizes their need to compete on price. 16 Antenna Systems & Technology Fall 2014 www.AntennasOnline.com http://www.AntennasOnline.com

Table of Contents for the Digital Edition of Antenna Systems & Technology - Fall 2014

Editor’s Choice
The GPS to GNSS Antenna Design Challenge
Dual-Polarized & Dual-Band Omni Directional Antennas
Ensuring Consistent Connectivity for Mission-Critical Applications
Antenna Systems 2014: Conference Preview
Antennas
Components/Subsystems
Software / System Design
Test & Measurement
Industry News
Marketplace
Mitigating Cellular Interference in Hospitals

Antenna Systems & Technology - Fall 2014