Waveguide Probe Coupler
Waveguide Probe Coupler extracts microwave signals using probe coupling technology for precise RF monitoring and measurement. Ideal for radar systems, microwave transmitters and laboratory RF test setups.
Precision Waveguide Probe Couplers for Electric Field Sampling
AO Microwave’s waveguide probe couplers provide coaxial signal sampling by tapping into the electric field (E-field) of rectangular waveguides. Machined from high-grade aluminum and copper alloys, these couplers insert a capacitive probe through the broad wall, typically centered where the E-field intensity is highest. Designed for loose, non-disruptive signal sampling, our probe couplers deliver high coupling values (typically 40 to 60 dB), maintaining a low insertion loss on the main transmission line and minimal impact on mainline VSWR.
By utilizing precisely calibrated probe depths, our couplers provide an effective way to sample signals for frequency counters, spectrum analyzers, and automatic gain control (AGC) loops. They offer a compact, lightweight monitoring solution for system test points where loose coupling is required.
| Part No | Frequency/GHz | Main VSWR (Max) | Sec VSWR (Max) | IL/dB (Max) | Coupling Optional/dB | Flange Type | Connector Type |
|---|---|---|---|---|---|---|---|
| AO229-WTCXNKPPACG | 3.22-4.90 | 1.1 | 1.25 | 0.2 | 30~60 | UDR40 | N Female |
| AO187-WTCXNKPPACG | 3.94-5.99 | 1.1 | 1.25 | 0.2 | 30~60 | UDR48 | N Female |
| AO159-WTCXNKPPACG | 4.64-7.05 | 1.1 | 1.25 | 0.2 | 30~60 | UDR58 | N Female |
| AO137-WTCXNKPPCSG | 5.38-8.17 | 1.1 | 1.25 | 0.3 | 30~60 | UDR70 | N Female |
| AO112-WTCXNKPPCSG | 6.57-9.99 | 1.1 | 1.25 | 0.3 | 30~60 | UBR84 | N Female |
| AO90-WTCXNKPPCSG | 8.20-12.5 | 1.1 | 1.25 | 0.3 | 30~60 | UBR100 | N Female |
| AO75-WTCXNKPPCSG | 9.84-15.0 | 1.1 | 1.25 | 0.3 | 30~60 | UBR120 | N Female |
| AO62-WTCXSKPPCSG | 11.9-18.0 | 1.1 | 1.25 | 0.3 | 30~60 | UBR140 | SMA Female |
| AO51-WTCXSKPPCSG | 14.5-22.0 | 1.1 | 1.25 | 0.3 | 30~60 | UBR180 | SMA Female |
| AO42-WTCX2.92KPPCSG | 17.6-26.7 | 1.1 | 1.5 | 0.3 | 30~60 | UBR220 | 2.92mm Female |
| AO34-WTCX2.92KPPCSG | 21.7-33.0 | 1.1 | 1.5 | 0.3 | 30~60 | UBR260 | 2.92mm Female |
| AO28-WTCX2.92KPPCSG | 26.5-40.0 | 1.1 | 1.5 | 0.3 | 30~60 | UBR320 | 2.92mm Female |
The Physics of Electric Field (E-Field) Probe Coupling
Probe couplers operate by capacitive coupling to the waveguide's electric field. In rectangular waveguides operating in the dominant TE10 mode, the electric field is oriented vertically, and its intensity peaks at the center of the wide wall. By inserting a small, conductive probe through the center of the broad wall, the probe acts as a small capacitive antenna, capturing a fraction of the electric field and routing it to the coaxial output port.
To prevent disrupting the main signal path, these couplers are designed for loose coupling (typically 40 to 60 dB). Inserting the probe too deeply into the cavity increases the coupling, but also introduces a capacitive mismatch that degrades mainline VSWR. AO Microwave carefully calibrates the probe insertion depth to ensure low mainline VSWR while capturing a clean, stable sample of the signal.
Overcoming Peak Power Breakdown Risks
- Mitigating Voltage Breakdown: Because the probe is positioned in the high E-field region of the waveguide, the probe tip concentrates electric field lines. Under high pulsed power, this concentration can lead to voltage breakdown. We utilize rounded probe tips and high-dielectric PTFE beads to prevent arcing.
- High Coupling Value Consistency: Coupling values are highly sensitive to probe depth. We use precise manufacturing and assembly alignment to maintain consistent probe depth and ensure stable performance.
- Clean Low-profile Integration: The right-angle coaxial output provides a clean, space-saving connection point for test cables and receiver systems.
Waveguide Probe Coupler FAQs
Need high-performance Waveguide Probe Couplers?
Specify your WR size, required coupling (40/50/60 dB), coaxial connector, and flange style — we'll quote in 24 hours.
