title: Gigahertz flexible graphene transistors for microwave integrated circuits.
abstract: Flexible integrated circuits with complex functionalities are the missing link for the active development of wearable electronic devices. Here, we report a scalable approach to fabricate self-aligned graphene microwave transistors for the implementation of flexible low-noise amplifiers and frequency mixers, two fundamental building blocks of a wireless communication receiver. A devised AlOx T-gate structure is used to achieve an appreciable increase of device transconductance and a commensurate reduction of the associated parasitic resistance, thus yielding a remarkable extrinsic cutoff frequency of 32 GHz and a maximum oscillation frequency of 20 GHz; in both cases the operation frequency is an order of magnitude higher than previously reported. The two frequencies work at 22 and 13 GHz even when subjected to a strain of 2.5%. The gigahertz microwave integrated circuits demonstrated here pave the way for applications which require high flexibility and radio frequency operations.
authors: Department of Electrical Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors: Chao-Hui
authors: CH
authors: Yeh
authors: Yi-Wei
authors: YW
authors: Lain
authors: Yu-Chiao
authors: YC
authors: Chiu
authors: Chen-Hung
authors: CH
authors: Liao
authors: David Ricardo
authors: DR
authors: Moyano
authors: Shawn S H
authors: SS
authors: Hsu
authors: Po-Wen
authors: PW
authors: Chiu