Waveguide Flange Shim
Waveguide Flange Shim improves mechanical alignment and RF continuity between waveguide connections. Commonly used in precision microwave assemblies, radar modules, satellite communication equipment and mmWave systems.
Precision Waveguide Flange Shims for Perfect Electrical Contact
AO Microwave’s precision waveguide flange shims are engineered to establish optimal electrical contact across flat waveguide flange interfaces (such as UBR-to-UBR or UG-381/U configurations). Fabricated from highly malleable, premium metal foils—including annealed copper, high-elasticity beryllium copper, and brass—our flange shims deform slightly under bolt torque to conform to microscopic surface irregularities. Operating up to 110 GHz, these thin metal shims prevent micro-arcing and minimize insertion loss at the joint. They are available in standard thicknesses (typically 0.05 mm to 0.15 mm) and finished with high-purity silver or gold plating to maintain low contact resistance.
By sealing microscopic air gaps, our flange shims provide an effective barrier against RF leakage. They are critical for high-power radar transmitters, millimeter-wave VNA setups, and high-performance communication lines.
| Part No | Frequency/GHz | VSWR (Min) | Standard Thickness/mm | Flange Type |
|---|---|---|---|---|
| AO650-WFS12PPACG | 1.13-1.73 | 1.05 | 12 | UDR14 |
| AO510-WFS12PPACG | 1.45-2.20 | 1.05 | 12 | UDR18 |
| AO430-WFS10PPACG | 1.72-2.61 | 1.05 | 10 | UDR22 |
| AO340-WFS10PPACG | 2.17-3.30 | 1.05 | 10 | UDR26 |
| AO284-WFS8PPACG | 2.60-3.95 | 1.05 | 8 | UDR32 |
| AO229-WFS8PPACG | 3.22-4.90 | 1.05 | 8 | UDR40 |
| AO187-WFS7PPACG | 3.94-5.99 | 1.05 | 7 | UDR48 |
| AO159-WFS7PPACG | 4.64-7.05 | 1.05 | 7 | UDR58 |
| AO137-WFS7PPCSG | 5.38-8.17 | 1.05 | 7 | UDR70 |
| AO112-WFS5PPCSG | 6.57-9.99 | 1.05 | 5 | UBR84 |
| AO90-WFS5PPCSG | 8.20-12.5 | 1.05 | 5 | UBR100 |
| AO75-WFS5PPCSG | 9.84-15.0 | 1.05 | 5 | UBR120 |
| AO62-WFS5PPCSG | 11.9-18.0 | 1.05 | 5 | UBR140 |
| AO51-WFS5PPCSG | 14.5-22.0 | 1.05 | 5 | UBR180 |
| AO42-WFS4PPCSG | 17.6-26.7 | 1.05 | 4 | UBR220 |
| AO34-WFS4PPCSG | 21.7-33.0 | 1.05 | 4 | UBR260 |
| AO28-WFS3PPCSG | 26.5-40.0 | 1.05 | 3 | UBR320 |
| AO22-WFS3PPCG | 33.0-50.0 | 1.1 | 3 | UG-383/U |
| AO19-WFS3PPCG | 40.0-60.0 | 1.1 | 3 | UG383/UM |
| AO15-WFS2PPCG | 50.0-75.0 | 1.1 | 2 | UG385/U |
| AO12-WFS2PPCG | 60.0-90.0 | 1.15 | 2 | UG-387/U |
| AO10-WFS2PPCG | 75.0-110.0 | 1.15 | 2 | UG387/UM |
The Physics of Air Gaps & Micro-Arcing in Flat Junctions
Flat-to-flat (UBR-to-UBR) waveguide junctions can suffer from microscopic surface imperfections. Even when bolted tightly, microscopic air gaps remain between the mating faces.
Under high peak RF power, these air gaps act as tiny capacitors, concentrating the electric field. This field concentration can trigger voltage breakdown, leading to micro-arcing inside the gap that can cause carbonization and physical damage to the flanges. AO Microwave's flange shims utilize malleable metal foils to fill these gaps, establishing continuous electrical contact to prevent arcing and ensure stable high-power transmission.
Target Applications & Operational Advantages
By providing optimal electrical contact and preventing RF leakage, our flange shims deliver critical performance in active systems:
High-Power Transmitter Plumbing
Function: Seals flat waveguide flange joints in high-power radar and satellite transmitter runs.
Advantage: Eliminates air gaps to prevent micro-arcing and flange damage under high peak and continuous power levels.
Millimeter-Wave Test Setups
Function: Establishes consistent, low-loss electrical contact between test equipment flanges.
Advantage: Gold-plated beryllium copper shims minimize contact resistance, ensuring highly repeatable measurements up to 110 GHz.
EMI-Shielded Waveguide Run Integrations
Function: Prevents RF leakage at flat-to-flat flange connections in sensitive environments.
Advantage: Provides high electrical conductivity across the interface, ensuring robust EMI containment and maintaining system integrity.
Waveguide Flange Shim FAQs
Need high-precision Waveguide Flange Shims?
Specify your WR size, material (Copper/Beryllium Copper), plating (Gold/Silver), and quantity — we'll quote in 24 hours.
