• ARCHITECTURAL CONSIDERATIONS FOR A VARIABLE BIT RATE DATA ACQUISITION TELEMETRY ENCODER

      Lee, Jeffrey C.; L-3 Communications – Telemetry-West (International Foundation for Telemetering, 2007-10)
      Modern telemetry systems require flexible bit rate telemetry encoders in order to optimize mission formats for varying data rate requirements and/or signal to noise conditions given a fixed transmitter power. Implementing a variable bit rate telemetry encoder requires consideration of several possible architectural topologies that place different system requirements on data acquisition modules within the encoder in order to maintain adequate signal fidelity of sensor information. This paper focuses on the requirements, design considerations and tradeoffs associated with differing architectural topologies for implementing a variable bit rate encoder and the resulting implications on the encoder systems data acquisition units.
    • LOW-NOISE SWITCHING POWER SUPPLY CONSIDERATIONS FOR TELEMETRY ENCODER APPLICATIONS

      Lee, Jeffrey C.; Steppler, Missy; L-3 Communications (International Foundation for Telemetering, 2007-10)
      Modern telemetry systems using state of the art field programmable gate arrays (FPGAs) and signal processing components require lower voltage supplies to support various CMOS core geometries while still needing multiple higher voltage rails to support legacy interfaces. Addressing these power supply requirements efficiently requires switching power supply topologies that if left unchecked can generate high input surge currents and high levels of detrimental noise for both the sensitive analog signal processing circuitry and the power supply input source. This paper focuses on the design considerations and tradeoffs associated with implementing an efficient telemetry encoder power supply while mitigating the resulting noise effects typically associated with switching power supplies. This noise can negatively affect the power supply input source and the linear signal processing circuitry within the telemetry encoder.