RO4730G3 is a flame-retardant antenna laminate in the RO4700 group with a nominal process Dk around three. It offers a useful middle position between lower-Dk antenna materials and more compact higher-Dk structures. Its documented Design Dk is derived over a lower microwave band, which matters when comparing entries from other families.
Material system
Ceramic-filled hydrocarbon thermoset reinforced with woven glass
Technical properties
| Property | Reported value | Conditions / source |
|---|---|---|
| Process dielectric constant | 3.00 ± 0.05 | Typical, 10 GHz, 23°C; IPC-TM-650 2.5.5.5 clamped stripline; direction is not separately recorded here. Source |
| Design dielectric constant | 2.98 | Typical; 1.7–5 GHz, differential phase length method; average across common constructions. Source |
| Dissipation factor | 0.0028 | Typical, 10 GHz, 23°C; IPC-TM-650 2.5.5.5; direction is not separately recorded here. Source |
| Thermal conductivity | 0.45 W/(m·K) | Typical; ASTM D5470, 50°C, through-thickness direction. Source |
| Thermal coefficient of dielectric constant | 34 ppm/°C | Typical; -50°C to 150°C, IPC-TM-650 2.5.5.5 (modified temperature measurement); 10 GHz. Source |
Typical reported values are not a purchase specification. Process Dk, design Dk and values measured at different frequencies are not interchangeable.
Selection and design notes
- Use it as a candidate for antenna feeds where repeatable phase length, panel processing and flame behavior all matter. Evaluate the chosen foil's loss contribution over the complete feed length, rather than using Df as a direct prediction of antenna efficiency.
- For a change from RO4725JXR, redesign the radiating element and feed network together; the material names do not denote electrically interchangeable grades.
Thickness and copper options
Order against the current RO4700 configuration table; core thickness affects both PIM comparisons and electrical dimensions.
Identify the exact low-profile foil option. Preserve the datasheet's copper-specific PIM conditions in any supplier comparison.
Fabrication considerations
- Agree laminate orientation, core tolerance and copper treatment before array optimization. Include representative coupons or test structures that distinguish dielectric variation from connector, solder-joint and assembly variation when debugging a PIM or insertion-loss problem.
Application fit
- Base-station antenna arrays
- Printed feeds
- Telecommunications radiators
Limits and substitution checks
- The published PIM response depends strongly on copper and test conditions. A supplier using another foil construction cannot inherit that result automatically, and a V-0 laminate classification does not by itself qualify an assembled antenna enclosure or complete product.