Add-on synthesis module for developing RF/microwave filters

Accelerated Filter Design

The iFilter™ integrated filter synthesis wizard runs seamlessly within the NI AWR Design Environment platform. It enables filter designers to accelerate design starts with powerful synthesis of lumped- and distributed-filter types, supporting the export of the resulting circuit topologies directly into Microwave Office software for further refinement, optimization, electromagnetic (EM) verification and physical design. 


The iFilter wizard offers a smart, interactive guide for developing a distributed- or lumped-element filter with a user-specified frequency response to mitigate interfering signals in a communication system.


Synthesis provides the filter topology and element parameter values that define an initial design, serving as a starting point for further optimization/verification and accelerating the overall design process.


iFilter designs can be directly imported into an NI AWR Design Environment project as a subcircuit for further design or integrated into a larger network or system.

Features at a Glance

  • Interactive Synthesis Step-by-step guide for designing filters with a user-specified frequency response and construction
  • Schematic/Layout Preview Real-time view of the synthesized filter topology with parameter values or physical layout of the distributed filter 
  • Response Plots  Instant frequency response plots of insertion/return loss, group delay, insertion phase, and more
  • Models  Replace ideal components with lossy elements (define Q) or real vendor components from the device library
  • Integrated  Directly export a schematic or layout into a subcircuit in an NI AWR Design Environment project

Filter Types

Filter Responses

Define a filter response from a desired passband response (low-pass, high-pass, bandpass, or bandstop), filter approximation function (transfer function) from comprehensive list of functions such as Chebyshev, Bessel, Maximally flat, Lagendre, and more, and construction type. For a given response, users can specify the preferred realization technology for the physical filter design.


Distributed element filters are obtained by using cascaded-transmission lines, cascaded-coupled lines, or multiple-coupled lines to synthesize the physical layout of shunt-stub bandpass, stepped-impedance resonator, edge-coupled, interdigital, hairpin, and combline bandpass filters. With the user-specified physical stack-up information of the substrate medium, iFilter provides feedback on higher-order modes, surface waves, and line widths for common characteristic impedances.

Lumped Element

Users choose from among the supported filter categories (lumped, narrowband lumped, coupled resonator, and more) for filters based on discrete, lumped-element components (inductors, capacitors) and define the coupling options (inductive/capacitive) for narrowband designs. Response specifications include filter order (N), center frequency, passband corners, bandwidth, insertion loss in the stop-band, shunt inductor value for a lumped, capacitively-coupled resonator bandpass filter, source/load terminations, and more.

Transmission Zeros

The iFilter wizard supports direct definition of transmission zeros or advanced filter designers and provides automated extraction of zeros and implementation of producible transforms.

Lossy or Real

Filter designers have the option to model lumped elements as a simple lossy inductor/capacitor. They can define the self-resonate frequency of an element (such as an inductor with a capacitive effect) to capture real-world parasitics or a commercially-available discrete inductor/capacitor by searching/replacing the ideal elements with a part from the software's internal vendor database.

Elements can be analyzed using the models selected on the lumped-model options dialog box/realization tab by clicking the design options button (models include real-world vendor data). Elements are mapped using the models selected on the lumped model options dialog box/realization tab by clicking the design options button. If a model does not include self-resonant frequency (SRF), INDQ/CAPQ mapping is used. Real-world vendor data is also mapped according to this criteria.