RF passive components serve as accessories for test equipment like RF power amplifiers, spectrum analyzers and EMI receivers. Directional couplers, capacitors and transformers are examples of common RF passive components, add-ons that sample electrical currents between test instruments and devices to ascertain the effectiveness of the test in progress. Directional couplers are one of the most common varieties of RF passive devices and are generally integrated into the system to perform monitoring and testing during the design stages; like many passive components, they enhance RF performance and reduce costs. Engineers also implement passive RF accessories to perform DC isolation, impedance matching and the matching of balanced ports to a single port. RF system designers are constantly faced with the challenge of shrinking a system’s size while retaining the expected output power, and small passive components provide the necessary level of power handling.