Coaxial Coupler
Coaxial Coupler samples RF signals with controlled coupling and high directivity. Ideal for power monitoring in radar transmitters, RF communication systems and microwave measurement setups.
Precision Coaxial Directional Couplers for Accurate Signal Sampling
AO Microwave’s high-precision coaxial directional couplers are designed to sample electromagnetic energy with high directivity and flat coupling up to 50 GHz. Fabricated inside rugged, passivated aluminum and copper cavities, these couplers utilize microstrip or stripline coupling networks printed on low-loss Rogers high-frequency laminates. Featuring gold-plated beryllium copper contacts and durable connector interfaces—including SMA, Type N, and 2.92mm (K)—our coaxial couplers deliver standard coupling values of 10, 20, or 30 dB, an exceptional directivity of typically > 20 dB, and minimal insertion loss on the main transmission line.
By utilizing precisely matched internal coupling lines, our couplers provide highly consistent power monitoring. They are critical for transmitter power leveling loops, active antenna array testing, and real-time VSWR monitoring in laboratory and military defense networks.
| Part No | Frequency/GHz | VSWR (Max) | IL/dB (Max) | Coupling/dB | Directivity/dB (Min) | Connector Type |
| AO0.5G2.5G-CC-6-SK | 0.5-2.5 | 1.20 | 0.50 | 6±1 | 20 | SMA Female |
| AO0.8G2.5G-CC-6-SK | 0.8-2.5 | 1.20 | 0.50 | 6±1 | 20 | SMA Female |
| AO1G4G-CC-6-SK | 1-4 | 1.20 | 0.50 | 6±1 | 20 | SMA Female |
| AO2G8G-CC-6-SK | 2-8 | 1.50 | 0.50 | 6±1 | 20 | SMA Female |
| AO6G8G-CC-6-SK | 6-8 | 1.50 | 1.00 | 6±1 | 15 | SMA Female |
| AO0.5G2.5G-CC-10-SK | 0.5-2.5 | 1.20 | 0.50 | 10±1 | 20 | SMA Female |
| AO0.5G6G-CC-10-SK | 0.5-6 | 1.20 | 0.70 | 10±1 | 18 | SMA Female |
| AO0.5G18G-CC-10-SK | 0.5-18 | 1.60 | 1.60 | 10±1 | 10 | SMA Female |
| AO0.8G2.5G-CC-10-SK | 0.8-2.5 | 1.20 | 0.50 | 10±1 | 20 | SMA Female |
| AO1G18G-CC-10-SK | 1-18 | 1.60 | 1.20 | 10±1 | 12 | SMA Female |
| AO2G8G-CC-10-SK | 2-8 | 1.20 | 0.50 | 10±1 | 20 | SMA Female |
| AO2G18G-CC-10-SK | 2-18 | 1.50 | 0.70 | 10±1 | 12 | SMA Female |
| AO4G8G-CC-10-SK | 4-8 | 1.20 | 0.60 | 10±1 | 20 | SMA Female |
| AO6G18G-CC-10-SK | 6-18 | 1.50 | 1.00 | 10±1 | 12 | SMA Female |
| AO0.5G2.5G-CC-20-SK | 0.5-2.5 | 1.20 | 0.40 | 20±1 | 20 | SMA Female |
| AO0.5G6G-CC-20-SK | 0.5-6 | 1.25 | 0.60 | 20±1 | 18 | SMA Female |
| AO0.5G8G-CC-20-SK | 0.5-8 | 1.30 | 0.80 | 20±1 | 14 | SMA Female |
| AO0.5G18G-CC-20-SK | 0.5-18 | 1.60 | 1.50 | 20±1 | 10 | SMA Female |
| AO0.8G2.5G-CC-20-SK | 0.8-2.5 | 1.30 | 0.50 | 20±1 | 18 | SMA Female |
| AO1G4G-CC-20-SK | 1-4 | 1.20 | 0.40 | 20±1 | 20 | SMA Female |
| AO2G8G-CC-20-SK | 2-8 | 1.20 | 0.40 | 20±1 | 20 | SMA Female |
| AO2G18G-CC-20-SK | 2-18 | 1.50 | 0.70 | 20±1 | 12 | SMA Female |
| AO6G18G-CC-20-SK | 6-18 | 1.50 | 0.60 | 20±1 | 12 | SMA Female |
| AO0.5G2.5G-CC-30-SK | 0.5-2.5 | 1.20 | 0.40 | 30±1 | 20 | SMA Female |
| AO0.5G6G-CC-30-SK | 0.5-6 | 1.40 | 0.70 | 30±1 | 12 | SMA Female |
| AO0.5G18G-CC-30-SK | 0.5-18 | 1.60 | 1.20 | 30±1 | 10 | SMA Female |
| AO0.8G2.5G-CC-30-SK | 0.8-2.5 | 1.20 | 0.40 | 30±1 | 20 | SMA Female |
| AO1G4G-CC-30-SK | 1-4 | 1.20 | 0.40 | 30±1 | 20 | SMA Female |
| AO1G18G-CC-30-SK | 1-18 | 1.60 | 1.00 | 30±1 | 12 | SMA Female |
| AO2G8G-CC-30-SK | 2-8 | 1.20 | 0.40 | 30±1 | 20 | SMA Female |
| AO2G18G-CC-30-SK | 2-18 | 1.50 | 0.70 | 30±1 | 10 | SMA Female |
| AO1G40G-CC-10-2.92K | 1-40 | 1.80 | 2.50 | 10±1.5 | 10 | 2.92mm Female |
| AO1G50G-CC-10-2.4K | 1-50 | 1.90 | 3.50 | 10±1.5 | 8 | 2.4mm Female |
| AO2G40G-CC-10-2.92K | 2-40 | 1.80 | 2.20 | 10±1.5 | 10 | 2.92mm Female |
| AO2G50G-CC-10-2.4K | 2-50 | 1.90 | 2.00 | 10±1.0 | 8 | 2.4mm Female |
| AO6G40G-CC-10-2.92K | 6-40 | 1.60 | 1.60 | 10±1.0 | 10 | 2.92mm Female |
| AO1G40G-CC-20-2.92K | 1-40 | 1.60 | 2.20 | 20±1.5 | 10 | 2.92mm Female |
| AO1G50G-CC-20-2.4K | 1-50 | 1.90 | 3.50 | 20±1.5 | 5 | 2.4mm Female |
| AO2G40G-CC-20-2.92K | 2-40 | 1.60 | 2.00 | 20±1.5 | 10 | 2.92mm Female |
| AO8G40G-CC-20-2.92K | 8-40 | 1.60 | 1.30 | 20±1.0 | 10 | 2.92mm Female |
| AO1G40G-CC-30-2.92K | 1-40 | 1.60 | 2.00 | 30±1.5 | 10 | 2.92mm Female |
| AO2G40G-CC-30-2.92K | 2-40 | 1.60 | 2.00 | 30±1.5 | 10 | 2.92mm Female |
| AO8G40G-CC-30-2.92K | 8-40 | 1.60 | 1.30 | 30±1.0 | 10 | 2.92mm Female |
Even and Odd Mode Dispersion in Microstrip Couplers
Microstrip directional couplers rely on electromagnetic coupling between parallel conductor lines. In microstrip topologies, the electromagnetic wave travels partly through the air dielectric and partly through the substrate. This difference in media causes the even-mode and odd-mode phase velocities to diverge at high frequencies, which is known as dispersion.
If left uncompensated, this velocity mismatch prevents complete destructive interference at the isolated port, degrading directivity. To resolve this dispersion, AO Microwave utilizes stripline structures or integrates compensated dielectric overlays in its microstrip couplers. Stripline configurations keep the wave confined entirely within a homogeneous dielectric, ensuring matching phase velocities and high directivity (typically > 20 dB) up to 50 GHz.
Target Applications & Operational Advantages
By providing high directivity and flat coupling, our coaxial directional couplers secure stable signal monitoring:
Transmitter Power Leveling Loops
Function: Samples forward power in active transmitter lines to provide feedback for automatic gain control (AGC) circuits.
Advantage: Flat coupling response (typically ±0.5 dB) ensures accurate, drift-free power leveling across wide frequency bands.
Active Antenna Array Calibration
Function: Samples phase and amplitude references in multi-channel phased array feed systems.
Advantage: Exceptional port matching and low insertion loss minimize systematic calibration errors, preserving beamforming precision.
Real-Time VSWR Monitoring
Function: Samples reflected power from antenna lines to protect power amplifiers from damage.
Advantage: High directivity (>20 dB) allows the system to accurately isolate the reflected wave from the forward wave, preventing false alarms.
Coaxial Coupler FAQs
Need high-performance Coaxial Directional Couplers?
Specify your connector interface (SMA/2.92mm/2.4mm), coupling value (10/20/30 dB), and frequency range — we'll quote in 24 hours.
