Filter Information and Design Software

• Tuned Filters Tuned filters utilize one or more tuned circuits (resonant or anti-resonant circuits) to separate signals in relatively-narrow bands of frequencies from signals wider frequency spectrums ...
  
  
  • Tuned LCR Filters Wideband Behaviour of Parallel-Tuned LCR Circuits C is in parallel with L and R in series. Z is the impedance measured across C. This deceptively simple circuit is found in narrow-band tuned amplifiers, wideband video amplifiers, impedance-matching L-networks and in filters, etc. ...
  • Preselector A Simple Preselector for Use Between Antenna & Radio Receiver A preselector attenuates strong unwanted signals in the same band as wanted weak signals. This prevents overload of high-gain receivers, improves signal-to-interference and signal-to-noise ratios, and reduces signal distortion. This preselector is a parallel-coil-and-capacitor tuned circuit with both the random length wire antenna and receiver tapped into the coil. The bottom end of the coil is grounded and it then becomes an impedance-matching transformer ...
• Wave Filters Wave filters can be considered artificial transmission lines with lumped components, as shown in these basic wave filter circuit examples ...
  
  
  • Band-PassSimple Coil & Capacitor Band-Pass (Bandpass) Filters The majority of L & C filters consist of one or more cascaded basic L-C sections used in applications where a small loss in the pass-band is of no consequence and frequencies of 'infinite' attenuation in the stop-band are not required. E.g., simple, switchable, bandpass filters at the input of radio receivers or at the output of radio transmitters where power-handling components may be needed ...
  • Low-Pass & High-Pass Simple, Coil & Capacitor, Low-Pass (Lowpass) & High-Pass (Highpass), T & Pi Filters The majority of L & C filters consist of one or more cascaded basic L-C sections used in applications where pass-band ripple and frequencies of infinite attenuation in the stop-bands are of no interest. E.g., simple power supply smoothing filters and harmonic suppression filters following RF power amplifiers This program assists with design of such simple filters without the operating inconveniences inherent in programs intended for more sophisticated designs ...