Antenna Systems & Technology - Fall 2013 - (Page 30)

FEATURE ARTICLE Addressing Customer Requirements in Public Safety Antennas By Kevin Burton, Field Applications Engineer - Laird Laird has a large presence in the public safety market, designing antennas and other solutions important to the communication efforts for police, fire and other emergency response workers. Because of interoperability issues, frequency needs and rugged environments, public safety customers often have their own set of requirements regarding antennas. When a statewide government public safety agency (Agency) set out to develop and implement an enhanced radio communications system, they reached out to Laird to assist in finding an antenna solution that would meet all of their requirements. In order for the Agency to carry out its mission of providing safety, service and security to the public, improved interoperability between regions was necessary. In cases where units from multiple regions were deployed to support an incident, a need for frequency pairing operating on wide spacing was crucial to minimize interference. A vital part of this project was increasing the separation between transmit and receive frequencies, which then required the installation of high quality wideband lowband antennas. The Agency had previously used our narrowband lowband antennas, and during the initial design discussions it was suggested that the Agency use a standard product tuned to a different frequency. However, it was soon determined that a standard product would not meet all of the requirements set forth by the Agency. Together, we were challenged to develop a new wideband antenna that would meet all requirements. The Requirements Because of the large area covered by the Agency and other factors, they had many requirements for the new antenna. It was necessary that a single antenna cover the entire lowband frequency pool. In addition to covering a wide frequency range, the antenna had to withstand extreme environmental conditions ranging from high heat to strong wind applications. Maintaining communications during a high speed pursuit was critical to the Agency, and the most challenging technically. In order to ensure the antenna would perform in this challenging environment, they required that the antenna operate with low Voltage Standing Wave Ratio (VSWR) while the whip was bent 90°, and that the antenna also survive while the radio was keyed up at full power (100 W) for 10 minutes without failure. The challenge of this particular antenna design was the combination of a wideband and lowband antenna that would also pass the power test and low VSWR requirements. Laird’s existing antenna designs, patents and expertise enabled the team to create a wideband solution that met all frequency requirements, while collaborating with experts from other areas of the company made it possible for the team to meet all of the customer’s other requirements. Meeting the Needs of the Customer While all public safety antennas are designed with low VSWR requirements, we had to ensure it could meet the design requirements of the Agency. Measuring the VSWR is one way to verify that the impedance is matched to the radio. The lower the VSWR, the better. If the VSWR is high, unwanted heat is generated within the antenna and flexing and bending of the antenna can create high VSWR, which can 30 Antenna Systems & Technology Fall 2013 www.AntennasOnline.com http://www.AntennasOnline.com

Table of Contents for the Digital Edition of Antenna Systems & Technology - Fall 2013

Editor’s Choice
Exponential M2M Market Growth Calls for Innovative RF and Antenna Solutions
Managing Distributed Antenna Systems Effectively and Efficiently
Millimeter Wave Antenna Radome Systems for Satellite on the Move Applications
Antennas
Components/Subsystems
Software/System Design
Test & Measurement
Antenna Systems 2013: Conference Preview
Marketplace
Industry News
Addressing Customer Requirements in Public Safety Antennas

Antenna Systems & Technology - Fall 2013