RF waveguide combiners and dividers are circuits that combine or divide radio frequency (RF) signals. RF waveguide combiners accept several input signals and produce a single, combined output signal. In hybrid varieties, the signal is split into different phases, each with equal amplitude. RF waveguide dividers are circuits that accept one input signal and output multiple signals. General specifications for both RF waveguide combiners and RF waveguide dividers include waveguide cross-section and waveguide material. Typically, the waveguide cross-section is rectangular, elliptical or circular. Common materials for RF waveguide combiners and dividers are aluminum, brass, bronze, copper, and silver.
Flange specifications for RF waveguide combiners and RF waveguide dividers include flange type, profile, and plating material. Union guide (UG) and connector pressurized rectangular (CPR) are the most common flange types. UG variants include cover or plate and choke. Cover or plate flanges are square and flat. Choke flanges have an O-ring groove and choke cavity. CPR flanges include connector pressurized rectangular flat (CPRF), connector pressurized rectangular grooved (CPRG), and connector miniature rectangular (CMR). Most RF waveguide combiners and dividers have a square, rectangular, or circle profile. Plating materials include cadmium, nickel, rhodium, silver and tin. Non-plated products are also available.
RF waveguide combiners and RF waveguide dividers carry performance specifications such as operating frequency range, EIA waveguide size, and VSWR. Operating frequency range is the range of operating frequencies over which RF waveguide combiners and dividers meet all guaranteed specifications. The Electronic Industry Alliance (EIA) approves the size of RF waveguide combiners and dividers. Voltage standing wave ratio (VSWR) is a unit-less ratio ranging from one to infinity, expressing the amount of reflected energy at the input or output of the device. A value of one indicates that all of the energy will pass through, while any other value indicates that a portion of the energy will be reflected.
RF waveguide combiners and RF waveguide dividers that are sold in Europe must comply with the Restriction of Hazardous Substances (RoHS). RoHS requires all manufacturers of electronic and electrical equipment sold in Europe to demonstrate that their products contain only minimal levels of the following hazardous substances: lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyl and polybrominated diphenyl ether. RoHS became effective on July 1, 2006. By definition, lead-free devices contain less than 1000 ppm lead by weight. Some RF waveguide combiners and dividers are suitable for programmable devices. Others are designed for military applications.