Voltage-controlled biphase attenuator and vector synthesizer for monolithic microwave signal processors

A GaAs monolithic voltage-controlled biphase attenuator and a vector synthesizer, which utilize remote-pinchoff cold field-effect transistors (RePOFETs), are newly developed for microwave signal-processor applications. Their features are very small circuit size, which permits dense integration, and high control linearity. Lumped-constant topologies and internal impedance optimization successfully reduce the sizes of the attenuator and vector synthesizer to just 0.5 and 2.1 mm² respectively. The control sensitivity deviation exhibited is within ±5% for over 50% of the full control range. The uniformity of the measured vector constellation is also improved by the RePOFETs