Why couplers matter
Directional couplers sample a known fraction of a signal without disturbing the main line. They are used for power monitoring, VSWR measurement, and signal injection in everything from test benches to radar front-ends.
Key specifications
- Coupling factor — the ratio, in dB, of incident power to the coupled port.
- Directivity — how well the coupler isolates the forward and reverse signals.
- Insertion loss — the loss introduced on the main line.
- Frequency range — couplers are specified over a band, not a single frequency.
- Power handling — the maximum CW power before thermal damage.
Choosing the right type
- Directional couplers — for sampling and monitoring.
- Hybrid couplers (90 and 180 degree) — for splitting and combining with phase control, closely related to power dividers.
- Bidirectional couplers — for measuring both forward and reflected power.
Practical tips
- Pick a coupling value that keeps the sampled signal within your detector range.
- Watch directivity — poor directivity corrupts return-loss measurements.
- Consider temperature stability for defense and aerospace applications.
- Browse our directional couplers.