Unique Features in FilterSolutions

Aside from the many unique features, FilterSolutions contains a myriad of useful features that are not commonly available in free or garden variety filter design tools.  All filter designers are encouraged to evaluate the 30 day trial.

Disclaimer:  The following features are believed to be unique in FilterSolutions.  Nuhertz cannot insure features are unique on a 100% basis, but bases its belief on market feedback and internal unique development programs.  If you do find an entry that is available elsewhere, please contact Nuhertz to inform us, so we can remove the uniqueness entry from our list.


Precisely computed transform synthesis (Lumped, active, switched cap, digital).   Synthesis is fully and precisely accurate and instantaneous.  No further optimization on the transform is needed.  No tables are employed.

Even/Odd asymmetric Chebyshev and Butterworth band pass designed with parametric techniques
  • Useful for minimizing number of poles required to meet asymmetric band pass design requirements.
 Precise Odd order Low Pass, Even Order High Pass Chebyshev
Asymmetric Elliptic band pass
  • Differing number of poles/zeros for high pass and low pass sides
  • Independent attenuation of stop band ratios for high pass and low pass sides
    • Useful for minimizing number of poles required to meet asymmetric band pass design requirements.
Precise Asymmetric Elliptic Bandpass
Bessel, Linear Phase, and Gaussian flat stop bands of arbitrary attenuation with tx zeros
  • Useful for maximizing cutoff steepness with flat group delays.
Linear Phase Flat Precise Stop Band
Constricted ripple Chebyshev pass bands, and Elliptic pass bands, stop bands, or both
  • Useful in minimizing required number of poles.
EllipticPrecise  Constricted Ripple on Pass Band and Stop Band
Single point ripple Chebyshev pass bands, and Elliptic pass bads, stop bands, or both
  • Useful for minimizing lumped element value spread and minimizing planar geometry extremes
Elliptic Precise Single Point Ripple on Pass Band and Stop Band

Half band ripple Chebyshev pass bands, and Elliptic pass bands, stop bands, or both

  • Only employs half the number of tx zeros in the stop band and/or pass band, while still maintaining complete flatness.
  • Useful for minimizing group delay spikes
Elliptic Precise Half Band Ripple on Pass Band and Stop Band
Multiband synthesis
  • Unlimited number of passbands may be synthesized in the same network, each independently adjusted in width.
    • Works with and without stop bands.
Elliptic Precise Multi Band


Delay Equalization  
Instantly computed delay equalizers with all-pass stages (not certain if this is unique, but it might be)
  • No manual interactions required
  • Useful in quickly and directly minimizing phase distortion
7 Pole Delay Equalized Chebyshev
Graphical, user-interactive zeros positioning with automated equiripple or maximally flat pass band restoration
  • Useful in customizing stop band response
  • Useful in customizing phase distortion
  • Useful in customizing frequency axis tx zero placement
Graphical Quadruplet Zero Placement While Maintaining Equiripple Pass Band


Lumped Element Filter Designs

Precisely computed odd order minimum inductor zigzags designed with parametric techniques (N-1 inductors, N is prototype order), Supported for Lumped Element Design Only

  • Narrow band zigzags
    • Useful to minimize inductor count
    • Useful to implement ultra-high Q crystal filters
  • Medium band zigzags and wide band
    • Useful to minimize inductor count
5 Pole Elliptic Bandpass with Precise Parametric Design 5 Pole Elliptic Band Pass with 4 Inductors
Automated lumped element computations to implement embedded quadruplet tx zeros into an LC network
  • Useful in minimizing element count when controlling phase distortion
  • Traditional all pole stages employ two pairs of cancelled poles and zeros.  Embedded quadruplet zeros do not.

Embedded Quadruplet Zeros Pole/Zero Plot   Embedded Quadruplet Zeros Group DelayEmbedded Quadruplet Zeros S11/S12 Embedded Quadruplet Zeros Schematic

Automated discrete element selection for capacitor and/or inductor element selection
  • Automatically selects the best capacitor and/or inductor from a user-customized database of S-Parameter and Spice models
 Discrete Elements S-Parameter SimulationAutomated Discrete Element Selection


Active Filter Designs
Instantly computes 3 pole stages, with and without tx zeros for Thomas, GIC, MFB, and S&K stages.  (S&K is only unique for 4 pole stages and 3 pole tx zero stages)
  • Low pass, high pass, band pass, low stop, high stop, and even stop stages supported.
 3 Pole Elliptic Simulation  3 Pole Elliptic Single MFB Stage
Instantly computes 4 pole all-pole stages for MFB and S&K stages
  • Low pass, high pass, and band pass are all supported.
 4 Pole Chebyshev  Simulation4 Pole Chebyshev Single S&K Stage
Discrete optimization for capacitor selection
  • Selects the best capacitor from a user-customized database of S-Parameter and Spice models
 Discrete Capacitor Elements SimulationDiscrete Capacitor Elements


Planar Filter Designs  
Instant, accurate, fully parameterized, and circuits optimized design straight from the engine.
  • Includes discontinuous effects for single and multi-layered boards of arbitrary layer geometries, and with or without a metallic cover of arbitrary height.
    • Discontinuous model simulations are all on-demand.  No prior data collection is necessary.
    • Output layouts are of suitable accuracy for direct insertion into EM optimizers.
  • Exports directly into many EM simulators/optimziers, both planar and full 3D, and DXF file format.
 9 Pole Planar Elliptic Simulation     9 Pole Planar Low Pass Elliptic
High pass overlay filters
  • Employs broadband coupled lines to emulate series capacitors for high pass filters in a suspended micro strip or strip line, with and without metallic cover.
11 Pole Planar High Pass Overlay Simulation      11 Pole Planar High Pass Overlay
Cascaded Quadruplet filters
  • Employs a series of single and quadruplet ring resonators or miniature hairpins to implement steep walled band pass filters with stop band zeros.
 10 Pole Planar Cascaded Quadruplets Simulation   10 Pole Planar Cascaded Quadruplets


Third Party Interfaces  
Automated port tuning for planar EM optimization
  • Employs EM tuning ports and circuits simulations to completely automate the EM optimization process within minutes and with only a few mouse clicks
    • Utilizes internally developed (unique) reconstruction algorithms for accurate planar reconstruction from optimized port tuned variables
    • Wide variety of topologies employed that greatly exceed those published in publicly available port tuning material.
Discrete optimization for capacitor and/or inductor element selection
  • Selects the best capacitor and/or inductor from a third-party partner library(s)
    • In-house third-party partner libraries
    • Modelithics
  • Employs discrete optimization to achieve best overall performance.
    • MDIF and Modelithics libraries
Interconnect optimization
  • Optimizes geometry needed to fine tune filter design response
    • Full set of geometric equations needed to ensure a valid layout following an optimization process for single elements, series LC resonators, and parallel LC resonators
Generic export process of a wide variety of parametrized layouts suitable for direct EM optimization
  • Export development process is normally functional within days, and the full portfolio of planar topologies can be on the market within weeks
  • Full set of geometric equations ensure layout integrity as assigned parameters are tuned or optimized
  • Initial layout is circuits-tuned and highly accurate, employing internal discontinuous modeling
  • Both single and multi-layered board layouts are supported.