Fast Tune Notch Filters

Source: Teledyne Defense Electronics, LLC

Fast Tune Notch Filters

Teledyne Defense & Space (TDS) offers a range of fast tune notch filters (FTNF) that have been designed to protect Electronic Support Measures (ESM) receivers from high duty cycle, frequency agile interference produced by on board (or cohort) combat radar systems. ESM sensors need protection from high-level, long pulse and frequency-agile radars.

Another application applies to Radar systems that are influenced by interference signals degrade the receiver dynamic range. Some common, less desirable, currently used mitigating techniques include:

  • Synchronous blanking of the ESM sensor
    • Probability of intercept of the ESM receiver is compromised when operating near a high duty cycle radar
    • Multiple emitters on the same platform compounds the problem
  • Front-end filtering of the radar pulses in the ESM sensor
    • Band-stop filters leave ”holes” in ESM sensor spectral coverage
    • YIG tuned filters are too slow to keep up with modern agile radar

TDS’s FTNF can track the emitter’s transmissions at its agility rate, ensuring that the ESM sensor’s Probability of Intercept is maintained at an acceptable level.

TDS is also working on a MMIC version on a 3mm x 3mm die, that has the additional ability to sniff the rejected signal to determine if it's still present. The current development design operates in X-Band with a 2-20GHz passband and rejection of approx. 40MHz inside a 1.5GHz window at X-band.

TDS Fast Tune Notch Products At-A-Glance

  • Modules for both S and X band coverage
  • Dual, independently controlled notches
  • Fast tuning speed (<250ns)
  • High rejection level
  • Low loss in all pass state


  • Fast tuning speed (<250ns)
  • High rejection level
  • Low loss in all pass state
  • Can be cascaded
  • Digital Tuning Control
  • Quickly switches from notch to all-pass
  • Good power handling


  • ESM Receiver Protection
  • Radar Front End & TR Modules
  • Direction Finding (DF) System Protection
  • EW (ESM)