▎ 摘　　要

This work presents the design, implementation, and characterization of the first thin-film integrated tunable microwave harmonic generator. The design is realized by exploiting the nonlinearity of four chemical vapor deposition (CVD) graphene-based diodes arranged in a nonlinear transmission-line (NLTL) approach. The used thin-film monolithic microwave integrated circuit (MMIC) technology is substrate independent. The fabricated prototype is realized on a 500-mu m transparent quartz substrate and occupies less than 1.2 mm(2) of chip area including pads. Measurement results show a wide input frequency range from 0 to 2.8 GHz with measured S-11 better than -10 dB. The measured second-harmonic conversion gain (CG) for an output frequency of 3.4 GHz is -21.6 dB. The measured third-harmonic CG for an output frequency of 3.15 GHz is -31 dB. To the best knowledge of the authors, the proposed circuit is the first tunable microwave harmonic generator combining graphene diodes in a NLTL topology on thin-film technology.