Vertical metal-insulator-graphene (MIG) diodes for radio frequency (RF) power detection are realized using a scalable approach based on graphene grown by chemical vapor deposition and TiO as barrier material. The temperature dependent current flow through the diode can be described by thermionic emission theory taking into account a bias induced barrier lowering at the graphene TiO interface. The diodes show excellent figures of merit for static operation, including high on-current density of up to 28 A cm, high asymmetry of up to 520, strong maximum nonlinearity of up to 15, and large maximum responsivity of up to 26 V, outperforming state-of-the-art metal-insulator-metal and MIG diodes. RF power detection based on MIG diodes is demonstrated, showing a responsivity of 2.8 V W at 2.4 GHz and 1.1 V W at 49.4 GHz.

In this work, a novel one-dimensional geometry for metal-insulator-graphene (1D-MIG) diode with low capacitance is demonstrated. The junction of the 1D-MIG diode is formed at the 1D edge of Al 2 O 3 -encapsulated graphene with TiO 2 that acts as barrier material. The diodes demonstrate ultra-high current density since the transport in the graphene and through the barrier is in plane. The geometry delivers very low capacitive coupling between the cathode and anode of the diode, which shows frequency response up to 100 GHz and ensures potential high frequency performance up to 2.4 THz. The 1D-MIG diodes are demonstrated to function uniformly and stable under bending conditions down to 6.4 mm bending radius on flexible substrate.

A large-signal model for GaN HEMT transistor suitable for designing radio frequency power amplifiers (PAs) is presented along with its parameters extraction procedure. This model is relatively easy to construct and implement in CAD software since it requires only DC and S-parameter measurements. The modeling procedure was applied to a 4-W packaged GaN-on-Si HEMT, and the developed model is validated by comparing its small-and large-signal simulation to measured data. The model has been employed for designing a switching-mode inverse class-F PA. Very good agreement between the amplifier simulation and measurement shows the validity of the model.

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