ROHACELL® is a closed-cell polymethacrylimide (PMI) structural foam used as a structural dielectric material in RF, microwave, and antenna PCB applications. It provides near-air electrical performance while maintaining mechanical stability and precise spacing.
ROHACELL® was originally developed for aerospace applications and is now widely used across multiple high-performance engineering industries.
Why Traditional PCB Materials Become Limiting at RF Frequencies
In RF, microwave, and antenna PCB design, traditional solid substrates can introduce limitations as operating frequency increases.
Common issues include:
- Increased dielectric loss
- Higher parasitic capacitance
- Added mass without functional benefit
- Sensitivity to small dimensional variations
At higher frequencies, electromagnetic behavior is governed by material properties and geometry rather than schematic design alone.
Electrical Properties of Rohacell® in RF Applications
ROHACELL® exhibits electrical behavior that closely resembles air.
Key electrical characteristics:
- Very low dielectric constant, close to 1
- Extremely low dielectric loss across RF and microwave frequencies
- Minimal impact on electromagnetic field distribution
These properties allow RF signals to propagate cleanly with reduced loss and distortion.
Mechanical Stability and Controlled Geometry
In RF and antenna systems, precise and stable spacing between conductive elements is critical. ROHACELL® provides mechanical support without electrically loading the system.
Benefits include:
- Stable geometry over temperature and time
- Predictable spacing in antenna and RF assemblies
- Structural support without degrading RF performance
ROHACELL® enables designers to separate electrical function from mechanical support.
Rohacell® Resin Uptake and RF Performance
ROHACELL® is a closed-cell PMI foam, which means resin uptake is tightly controlled during bonding and composite processing.
Resin behaviour in ROHACELL®:
- No bulk resin absorption
- No capillary wicking through the core
- Resin interaction limited to surface wetting and bonding interfaces
This controlled resin uptake ensures:
- Consistent dielectric properties
- Predictable mass and balance
- Repeatable RF performance from prototype to production
Machining and Manufacturing Behaviour
ROHACELL® machines cleanly using CNC machining, laser cutting, and conventional methods.
Manufacturing advantages:
- Accurate production of RF spacers and supports
- Clean edges and stable surfaces
- Repeatable bonding behaviour
ROHACELL® maintains dimensional stability during processing and in service.
Cross-Industry Adoption of Rohacell®
ROHACELL® is a cornerstone material for composite core applications and a proven problem-solver for engineers across multiple industries.
Industries using ROHACELL® include:
- RF, microwave, and antenna design
- Satellite and aerospace systems
- UAV and aviation structures
- Motorsport and mechanical engineering
- Marine and advanced electronics
Across these applications, engineers value ROHACELL® for its combination of lightweight stiffness, dimensional stability, machinability, and predictable performance.
That breadth of adoption is the result of consistent, repeatable results.
Typical RF and PCB Applications
ROHACELL® is commonly used in RF and microwave systems as a structural dielectric rather than a traditional laminate.
Typical applications include:
- Antenna and RF spacer structures
- Controlled-distance PCB assemblies
- Microwave modules and waveguide supports
- Radomes and RF-transparent enclosures
- 5G, satellite, UAV, and aerospace electronics
So why Rohacell® in RF and microwave design?
ROHACELL® provides near-air electrical performance, controlled resin uptake, and mechanical stability in RF and microwave applications. Its closed-cell PMI structure ensures predictable behavior, repeatable manufacturing, and reliable system performance.
For RF and PCB designers working where loss, weight, and geometry matter, ROHACELL® remains a proven and trusted material choice.
