RF Band Pass Filters for Positive Train Control Applications

PolyPhaser has introduced two new filters specifically for positive train control (PTC) applications. 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 in the United States 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 key industry standards for shock, vibration, temperature and filtering.

The RRF Series includes two core configurations:

The RRF-ITC-220-NFF is a band pass filter surge protector designed for 220 MHz railroad applications. Specifically engineered for positive train control systems where ITC radio signals are present.

Key Features

  • Engineered to reduce interference by blocking unwanted signals due to co-location
  • 50 Ohms impedance
  • Two port unit designed to pass ITC radio signals
  • Max Power Input 20 W with 100% duty cycle 75 W peak

The RRF-ACE-220-NFF is a band pass filter surge protector for ACSES radio signals designed for 220 MHz railroad networks. Engineered for safe and secure positive train control applications to reduce interference issues by blocking unwanted signals due to co-location. 

Key Features

  • 50 Ohms impedance
  • Two port unit designed to pass ACSES radio signals
  • Max Power Input 20 W with 100% duty cycle
  • All ports are DC short circuited