MACOM's MA4AGSW1A is an Aluminum-Gallium Arsenide anode enhanced, SPST Non-Reflective PIN diode switch. AlGaAs anodes, which utilize MACOM's patent pending hetero-junction technology, produce less loss than conventional GaAs processes, by as much as a 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 lower series resistance, lower capacitance, and faster switching speeds than Silicon based devices. 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. Offchip bias circuitry is required and allows for maximum design flexibility. The output port of this device ( J2 ), is 50 ? terminated during Isolation mode, which allows this signal to be absorbed rather than reflected back. This functionality makes it ideal for instrumentation and radar applications. This absorptive switch can be added to available reflective AlGaAs switches to improve isolation VSWR and increase isolation magnitude. The ultra low capacitance of the PIN diodes makes it ideal for usage in lower loss and higher isolation microwave and millimeter wave switch designs through 70 GHz. The lower series resistance of the AlGaAs diodes reduces the total insertion loss and distortion of the devices. These AlGaAs PIN switches are used as the switching arrays for radar systems, radiometers, and other multi-function components.
