VIRIDYN RO-Series: Superhydrophobic, RF-Transparent Coatings for Antenna Systems
The Challenge
A manufacturer of antenna systems needed a replacement for a discontinued, approved superhydrophobic coating (NTT HIREC® 450) previously used to protect antenna surfaces in demanding outdoor conditions. The replacement had to preserve RF performance while preventing water retention that can degrade signal transmission during rain events.
The customer specified stringent performance targets:
Static water contact angle of at least 150°
Roll-off angle no greater than 10°
Rain-condition RF insertion loss no greater than 0.5 dB for at least 30 minutes
Dry-film thickness of 20 µm or less.
The coating also needed to retain strong water repellency after abrasion, with a contact angle of at least 140° and roll-off angle no greater than 15°.
Compatibility with spray application methods.
The customer has assessed several alternative materials, but none had not met the application’s durability needs. The customer reported flaking or scaling after drying and loss of surface integrity on fiberglass substrates.
The Solution
ViriDyn recommended RO4, a superhydrophobic, RF-transparent coating. Given the urgency of the supply-chain disruption, ViriDyn moved quickly to supply a sample so the customer’s engineering team could validate the material against its antenna-performance requirements.
| Operating Frequency | RF insertion loss (decibels dB) | Ku, K, and Ka Bands (12 – 40 GHz) | Less than 2 decibels DB |
|---|---|
| Millimeter-Wave Bands (76 – 81 GHz+) | Less than 2 decibels DB |
During the evaluation discussion, VIRIDYN also proposed RO6 as an additional candidate to help identify the best balance of hydrophobicity, abrasion resistance, surface integrity, and application behavior. An RO6 sample was also dispatched for comparative testing.
The Outcome
The customer received RO4 for testing, followed by RO6 for side-by-side evaluation. This gave the engineering team two RF-transparent, superhydrophobic candidates to assess against the legacy coating benchmark and the program’s water-shedding, abrasion, thickness, and rain-related RF-loss criteria.
By providing multiple formulation options and supporting a spray-based validation path, ViriDyn is helping the customer to move from a discontinued material with no acceptable substitute toward a targeted qualification program for high-performance antenna protection.