Schottky Diode-Based T-shaped Phase Shifter MMIC in Aligned Carbon Nanotube Array Technology

This paper presents the design and fabrication of a T-shaped phase shifter monolithic microwave integrated circuit (MMIC) based on Schottky diode technology in aligned carbon nanotube (A-CNT) arrays. The excellent frequency response of A-CNT Schottky diode make them ideal for millimeter-wave applications. The phase shifter exhibits a simulated insertion loss of -10 dB and a return loss better than -10 dB, and a phase shift of 90° at 40 GHz. Measurement results further confirm a maximum phase shift of 72° at 34 GHz. The chip size is 0.19 mm². Compared to traditional T-shaped phase shifters, the A-CNT-based phase shifter exhibits a larger phase shift range and a reduced chip footprint. This study highlights the potential of A-CNT Schottky diode technology for next-generation millimeter-wave communication and radar applications.