MACOM's MA4AGSW4 is an Aluminum-Gallium-Arsenide anode enhanced, SP4T PIN diode switch. AlGaAs anodes, which utilize MACOM's patent pending hetero-junction technology, which produce less loss than conventional GaAs processes, as much as 0.3 dB reduction in insertion loss at 50 GHz. These devices are fabricated on a OMCVD epitaxial wafer using a process designed for high device uniformity and extremely low parasitics. The diodes themselves exhibit low series resistance, low capacitance, and fast switching speed. They are fully passivated with silicon nitride and have an additional layer of a polymer for scratch protection. The protective coating prevents damage to the junction and the anode airbridges during handling. Off-chip bias circuitry is required and allows maximum design flexibility. Applications The low capacitance of the PIN diodes used makes it ideal for use in microwave multi-throw switch designs, where the series capacitance in each off-arm will load the input. Also, the low series resistance of the diodes helps the total insertion loss of the devices at microwave frequencies. These AlGaAs PIN switches are used as the switching arrays for radar systems, radiometers, and other multi-assembly components.