Waveguide Pressure Window
Waveguide Pressure Window maintains environmental sealing while allowing efficient microwave transmission. Commonly used in radar systems, satellite communication equipment, aerospace applications and high-frequency RF systems.
Precision Waveguide Pressure Windows for Hermetic RF Isolation
AO Microwave’s high-vacuum and pressurized waveguide pressure windows are engineered to provide a reliable environmental seal within waveguide runs while remaining highly transparent to propagating RF energy. Seamlessly integrating advanced window dielectrics—such as high-purity quartz, sapphire, alumina ceramics, Kapton, and mica—into precision-machined aluminum and copper frames, our windows deliver a stable VSWR of < 1.15:1 and low insertion losses of < 0.10 dB. Operating across standard bands up to 110 GHz (WR-90 to WR-10), these hermetic barriers are designed to hold gas differential pressures up to 30 PSI, ensuring stable system isolation under severe operating conditions.
By establishing a gas-tight, low-loss partition, our pressure windows isolate indoor shelters from humid outdoor antenna environments, or secure pressurized gas runs inside high-power radar transmitters. They prevent dielectric breakdown and protect sensitive receivers from moisture, salt spray, and atmospheric contaminants.
| Part No | Frequency/GHz | VSWR (Max) | IL/dB (Max) | Average Power/W (Max) | Pressure/MPa | Thickness/mm | Flange Type 1 | Flange Type 2 |
|---|---|---|---|---|---|---|---|---|
| AO650-WPW30PMACG | 1.13-1.73 | 1.25 | 0.2 | 5000 | 0.1 | X=30 | UDR14 | PDR14 |
| AO510-WPW30PMACG | 1.45-2.20 | 1.25 | 0.2 | 3000 | 0.1 | X=30 | UDR18 | PDR18 |
| AO430-WPW20PMACG | 1.72-2.61 | 1.25 | 0.2 | 3000 | 0.1 | X=20 | UDR22 | PDR22 |
| AO340-WPW25PMACG | 2.17-3.30 | 1.25 | 0.2 | 2000 | 0.1 | X=25 | UDR26 | PDR26 |
| AO284-WPW30PMACG | 2.60-3.95 | 1.25 | 0.2 | 2000 | 0.1 | X=30 | UDR32 | PDR32 |
| AO229-WPW20PMACG | 3.22-4.90 | 1.25 | 0.2 | 1500 | 0.1 | X=20 | UDR40 | PDR40 |
| AO187-WPW8PMACG | 3.94-5.99 | 1.25 | 0.2 | 1000 | 0.1 | X=8 | UDR48 | PDR48 |
| AO159-WPW10PMACG | 4.64-7.05 | 1.25 | 0.2 | 800 | 0.1 | X=10 | UDR58 | PDR58 |
| AO137-WPW20PMCSG | 5.38-8.17 | 1.25 | 0.3 | 600 | 0.1 | X=20 | UDR70 | PDR70 |
| AO112-WPW10PMCSG | 6.57-9.99 | 1.25 | 0.3 | 500 | 0.1 | X=10 | UBR84 | PBR84 |
| AO90-WPW20PMCSG | 8.20-12.5 | 1.25 | 0.3 | 500 | 0.1 | X=20 | UBR100 | PBR100 |
| AO75-WPW20PMCSG | 9.84-15.0 | 1.25 | 0.3 | 300 | 0.1 | X=20 | UBR120 | PBR120 |
| AO62-WPW12PMCSG | 11.9-18.0 | 1.25 | 0.3 | 300 | 0.1 | X=12 | UBR140 | PBR140 |
| AO51-WPW12PMCSG | 14.5-22.0 | 1.25 | 0.3 | 200 | 0.1 | X=12 | UBR180 | PBR180 |
| AO42-WPW10PMCSG | 17.6-26.7 | 1.25 | 0.3 | 100 | 0.1 | X=10 | UBR220 | PBR220 |
| AO34-WPW10PMCSG | 21.7-33.0 | 1.25 | 0.3 | 80 | 0.1 | X=10 | UBR260 | PBR260 |
| AO28-WPW10PMCSG | 26.5-40.0 | 1.25 | 0.3 | 50 | 0.1 | X=10 | UBR320 | PBR320 |
Tuning & Dielectric Selection for High-Frequency Windows
Waveguide pressure windows introduce a dielectric material into the active RF path. Because the dielectric constant of window materials (ranging from 2.5 for Kapton to > 9.0 for Alumina Ceramic) is significantly higher than that of air, the window acts as a capacitive discontinuity, which can degrade the VSWR if left uncompensated.
To resolve this impedance mismatch, AO Microwave uses a resonant iris tuning design. By incorporating inductive steps or iris apertures adjacent to the window element, we cancel out the capacitive loading introduced by the dielectric. This simulation-tuned inductive-capacitive compensation provides flat, broadband VSWR characteristics, allowing the window to operate with negligible return loss across full waveguide bands.
Target Applications & Operational Advantages
By providing environmental isolation with low insertion loss, our waveguide pressure windows secure stable system performance in demanding RF environments:
Pressurized Radar Feed Systems
Function: Seals dry nitrogen or sulfur hexafluoride (SF6) gas inside the transmitter waveguide runs.
Advantage: Prevents voltage ionization and arcing at megawatt-level peak powers, protecting the radar source while introducing negligible insertion loss (< 0.08 dB).
Outdoor Satcom Ground Stations
Function: Separates outdoor feed assemblies from dehumidified indoor shelter waveguide runs.
Advantage: Blocks moisture, heavy rain, and humidity from entering sensitive indoor RF receivers, maintaining long-term system reliability in humid marine climates.
Vacuum Chamber Interfaces
Function: Seals vacuum testing environments from the external atmosphere during RF signal transmission.
Advantage: Sputtered glass-to-metal seals provide outstanding vacuum integrity (leak rates < 1x10-8 atm cc/s) with highly stable, low outgassing rates.
Waveguide Pressure Window FAQs
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