Ultra thin microstrip phase shifter based on carbon nanotube membranes

The size of traditional microstrip phase shifter is large, which hinders its further application in MMIC with higher integrated level. In this paper, we investigate the electromagnetic absorption and phase shift of carbon nanotube membranes with thickness less than 0.1 mm in microstrip circuits in the range of 0.5 GHz to 8 GHz. Phase shift reaches 20° when frequency higher than 7 GHz. Meanwhile, the insert loss of such carbon nanotube membranes is less than 0.7 dB, which provide a new method for phase shifter design in MMIC.