New PolyPhaser RF Band Pass Filters Address Radio Interference Issues in Positive Train Control (PTC)

Friday, January 6, 2017

Addressing a key challenge facing positive train control (PTC) applications in the Northeast Corridor, PolyPhaser has released two new filters in its RRF Series of Band Pass filters. The RRF Series of Band Pass Filters are engineered specifically to minimize RF interference between Interoperable Train Control (ITC) bands and Advanced Civil Speed Enforcement System (ACSES) bands. These filters increase the effectiveness and reliability in communications in those PTC systems.
The Northeast Corridor has a unique issue in that PTC systems may have interference from co-located PTC radios operating at different frequencies. In the example of the Northeast Corridor, freight railroads utilize 220 MHz (ITC) radios on the same or nearby tracks as 219 MHz (ACSES) radios used by transit trains. The new PolyPhaser RRF filters reduce interference issues by blocking unwanted signals created in these types of co-location environments.
Engineers at PolyPhaser worked closely with U.S. railroad operators to identify key requirements for the RFF Series, and developed the products to address these specific issues. These RRF filters were independently tested to meet or exceed key industry standards for shock, vibration, temperature and filtering.
“PolyPhaser continues to solve major problems in the market by leveraging its technology.” says Robert Cid, Global Product Manager for PolyPhaser products. “We solved a key issue facing the rail industry in the North-East Corridor. Due to the importance of the application, these filters were made available weeks after rail operators agreed to the filter specifications.”
The RRF Series includes two core configurations:   
PolyPhaser RF Series Band Pass Filters are available today from PolyPhaser and the company’s global networks of representatives, resellers and distributors. Learn more at
About PolyPhaser
Part of the Smiths Microwave family of brands, PolyPhaser leads the market with patented RF protection solutions for communications systems. Through innovative RF engineering and manufacturing capabilities, PolyPhaser provides protection technology that virtually assures uninterrupted communications flow of data and information through global networks.
About Smiths Microwave
Smiths Microwave is a leading provider of components, sub-assemblies, antennas and system solutions that test, filter, protect, and process high-frequency signals primarily for defense, aerospace, test and measurement, and wireless telecommunications applications.
As a family of brands, TECOM, TRAK, Millitech, EMC Technology, Florida RF Labs, LORCH, TRAK Limited, Kaelus, PolyPhaser, Transtector Systems, and RadioWaves provide exacting antenna system solutions for the military and commercial aerospace, as well as transceivers, frequency sources, timing systems, component applications and a wide range of innovative RF, microwave and surge protection solutions for the wireless telecommunications sector.
Alongside Smiths Connectors and Smiths Power, Smiths Microwave is part of the Smiths Interconnect division of Smiths Group (, a global leader in applying advanced technologies for markets in threat and contraband detection, energy, medical devices, communications, and engineered components. Smiths Group employs more than 23,000 people in over 50 countries.