6∼18 GHz GaAs PHEMT 6-bit MMIC digital phase shifter

A 6~18 GHz GaAs PHEMT monolithic microwave integrated circuit(MMIC) digital phase shifter is presented. Based on our special design of both the series Pseudomorphic High Electron Mobility Transistor (PHEMT) and shunt PHEMT control feeders, the MMIC possesses the feature of excellent return loss characteristic. Amplitude compensation techniques are used in the MMIC design to make sure high phase shift precision when the phase shift state varies. Performance redundancy optimization strategy is used to get the best performance. On-wafer measurement results of the developed MMIC chip in the 6-18-GHz band shows that the phase shift error is less than 5.625°±2°, 11.25°±2°, 22.5°±3°, 45°±4°, 90° ±7°, 180°±6.5°, the insertion loss is within the range of 8.6 dB~12.3 dB, input and output VSWR of 64 phase shift states is less than 2.1. The chip size is only 3.555 mm×4.055 mm×0.1 mm. To ensure high yield, Performance redundancy optimization strategy is used in design, and PCM (Process Control Map) and SPC(Statistics Process Control) technology are used in fabrication. The yield is more than 85%.