Product Design Spotlight – EMI Filters: High Frequency Filtering Performance

High Current Feedthrough Filter - Installation ExampleAs one of NexTek’s primary product lines, our range of High Current Feedthrough EMI Filters incorporate some advanced design features which make them unique. NexTek HPR Series filters are high-performance, military-grade designs that are built under stringent quality control systems and procedures. This post will focus on the High Frequency Filtering performance of NexTek’s HPR Series of EMI/RFI filters.

Why does High Frequency Filtering Performance matter?: The primary purpose of a feedthrough EMI/RFI filter is to eliminate radio frequency noise from a power cable. Maintaining adequate filtering performance to 1GHz and above ensures that noise in this frequency range can be effectively removed.

How do NexTek Solutions Differ?: Available high-current feedthrough filter solutions from other manufacturers’ do not use the same type of design, and this means that their filtering performance (as limited by the package and overall design) reaches a peak value and then falls off quickly afterward. In this case, maximum insertion loss is only achieved over a narrow band and the filter’s performance in the upper

C-Type Filter Comparison
C-Type Filter Comparison – NexTek HPRs Use Ceramic Caps (Red Line)

MHz ranges is limited and continues to get worse as the frequency rises.

With the HPR series, the design has been optimized to maintain excellent filtering and loss characteristics to and beyond 1GHz. There is no other C-type filter family available with similarly excellent high-frequency performance.

Practical Example: Let us say that a given power supply is emitting noise in the 500MHz range, and a filter must be found and selected to ensure compliance with an applicable EMI Emissions industry standard. When exploring the market to identify possible solutions, it becomes clear that most feedthrough filters for high-current lines do not maintain maximum filtering performance to 500MHz. On the other hand, NexTek’s HPR series of feedthrough filter designs maintain relatively flat Insertion Loss performance through 1GHz. In this case, the direct filtering level comparison (xx dB down at 500MHz) demonstrates that the HPR series provides superior performance and is well-suited to this application.

Summary: NexTek HPR Series of EMI/RFI feedthrough filters incorporate some advance design techniques that are unique within the industry, allowing high filtering performance to be maintained to extremely high frequency ranges. When this high filtering performance is combined with other design factors such as their compact size, extremely rugged construction, and wide range of available Cap Values and Voltage Ratings…the HPR series of filters are leading-edge solutions.


Learn More:

Product Family Page – High Current Filters (link)

Article – High Current Filtering, Pt 1 (link to blog post)

Article – High Current Filtering, Pt 2 (link to blog post)

Resources Page (link)