Planar Waveguide Vent

Planar Waveguide Vent for High-Frequency Communication Systems

High-frequency comms gear. Airflow and shielding are linked. Power dense. Temp control needed. Frequencies >1 GHz sensitive. Vents often problematic.

Planar Waveguide Vent usually considered when normal openings start leaking in scans.

Vents at High Frequency

Small perforations act differently. Wavelength short. Energy escapes even through narrow gaps. Enclosure looks closed. Scans show leakage near vents.

Planar Waveguide Vent: narrow conductive channels. Below cutoff dimensions → energy attenuates. Airflow passes. Vent not a gap.

Geometry Controls Performance

Channel width, length, wall thickness, conductivity. Mesh or perforation cannot replace. Small shifts affect attenuation. Stability critical. Manufacturing tolerance critical.

Airflow vs Shielding

Processors, RF modules, power electronics generate heat. Cooling needed. Shielding must hold.

Tuning:

channel depth → attenuation

opening ratio → airflow resistance

wall thickness → stiffness

Goal: predictable thermal, controlled EMI. Not maximum airflow.

Material

Aluminum: light, conductive, easy to form.

Stainless/plated: added stiffness if stability needed.

Surface finish: contact continuity under vibration/temperature.

Stability Over Peak

Predictable, repeatable shielding > maximum theoretical attenuation. Slightly lower but stable better. Geometry consistency → repeatable EMC.

Takeaway

Once vents show emissions, airflow and shielding cannot be separate. Planar Waveguide Vent keeps airflow while preserving shielding. Geometry and material more important than airflow or peak attenuation.