Narrowband Planar Filter Design with NI AWR Design Environment Software

Abstract:

Planar microwave filters can be found in low cost PCB environments as well as higher performance thin-film technologies. The number of potential topologies to consider and the design trades to be made can be intimidating for the non-expert. Fortunately, there is a straightforward design flow that can efficiently address this design challenge.

This design flow starts with narrowband filter design concepts pioneered by Dishal. On top of that we layer modern cross-coupled filter concepts developed by Atia, Williams, Cameron and others. Once we have a circuit theory based prototype, we can turn it into an EM model using NI AWR Design Environment (EMSight/AXIEM). Next we apply port tuning concepts developed by Swanson and Wenzel to bring the EM model into perfect equal ripple tune. The resulting circuit theory based tunings are a direct indication of the direction and relative magnitude of every resonator and coupling error in the filter. The physical dimensions of the filter can then be adjusted with relatively few EM simulations of the complete filter. The outlined procedure is much more efficient and intuitive than a brute force optimization of filter dimensions in an EM simulator.

Who should attend:

This material is suitable for filter designers, RF component designers, system engineers, experienced technicians and technical managers. Some previous experience with Method of Moments field-solvers would be helpful but is not required. Math skills above basic algebra are not required. The emphasis is on practical, proven procedures that are easy to follow rather than filter theory.

Presenter Bio:

Mr. Swanson received his BSEE degree from the University of Illinois and his MSEE degree from the University of Michigan. He has designed broadband amplifiers, various types of oscillators, thin-film filters and high Q cavity filters for both military and commercial applications. He is currently developing software tools for filter design and optimization with his partner Bob Wenzel. Mr. Swanson is the principal author of Microwave Circuit Modeling Using Electromagnetic Field Simulation. He is presently teaching several continuing education courses on filter design and EM simulation. Mr. Swanson is a Fellow of the IEEE and has served the IEEE MTT Society in many capacities.