Rohacell® in RF, Microwave, and Antenna PCB Applications

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.

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Why Traditional PCB Materials Become Limiting at RF Frequencies

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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.

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Electrical Properties of Rohacell® in RF Applications

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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.

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Mechanical Stability and Controlled Geometry

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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.

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Rohacell® Resin Uptake and RF Performance

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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

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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.

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Cross-Industry Adoption of Rohacell®

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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.

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Typical RF and PCB Applications

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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
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So why Rohacell® in RF and microwave design?
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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.

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