An RF Directional Coupler is a passive 4-port device which accepts an input RF signal and divides it into 2 output signals. These output signals are quite unequal in amplitude: the outputs differ in power level by the coupling value, in dB. The larger signal is at the main-line output port. The smaller signal is at the coupled port. The fourth port is called the “Isolated” port and is typically terminated with a resistor (when terminated internally, the isolated port is usually unavailable). RF Directional Couplers are used in many circuit and system applications, such as Test & Measurement, RF amplifiers, transmitters and receivers.
Richardson RFPD carries a wide assortment of RF Directional Couplers, including coaxial-connectorized, surface mount, and waveguide type units. These products cover frequency ranges from 10 MHz to 18 GHz, including octave and multi-octave ranges in 5dB to 30dB values. Performance grades range from low-cost commercial to rugged military.
Specific attributes which are important in selecting the right RF Directional Coupler for your application include: Type (Connectorized, Surface Mount or Waveguide); Power (W) – maximum input level; Frequency Range (GHz) of Operation; Coupling Value/Precision (dB), Directivity (dB); Insertion Loss (dB); Dimensions; and VSWR (ratio).
