330-500 GHz Graphene-Based Single-Stage High-Order Subharmonic Mixer

Abstract

In this work, a graphene-based single-stage high-order subharmonic mixer is presented. The device is able to up-and downconvert a signal in the 330-500 GHz frequency range, using a local oscillator signal with frequency located in the 26-40 GHz band. It exploits the strong nonlinear electromagnetic behavior exhibited by macroscopic graphene sheets when they are exposed to an incident electromagnetic wave to generate the output signal as a mixing product between the input signal and a high-order harmonic component of the local oscillator, which is internally generated without requiring additional circuitry. A prototype was implemented and its performance was experimentally characterized considering several different local oscillator multiplication orders. The maximum measured downconversion gain is around −50 dB, whereas the maximum output signal reached when working as upconverter is −43 dBm at 340 GHz and −63 dBm at 480 GHz. These values are good enough to be used in practical short-range applications. Furthermore, the measurement results are in good agreement with the theoretical predictions about graphene behavior.

Millimeter wave difference-frequency mixing by mobile carriers in gated monolayer graphene with broken centrosymmetry

“…Recently, several experimental groups have reported a significant performance improvement of graphene-based mixers exploiting the non-linear response of graphene in the millimeter and the submillimeter wave band [4][5][6][7][8][9]. In particular, Fernando Las Heras and coworkers succeeded in designing and producing graphene-based subharmonic mixers operating with high conversion efficiency within the millimeterwave band [4,5,9]. Tong et al [7] described the construction of a graphene-based millimeter wave mixer with low conversion loss and very broad bandwidth, exceeding 50 GHz, which is unprecedented for graphene microwave mixers.…”

“…To gain an insight into the underlying physics and the device application potential of the difference-frequency generation (DFG) in graphene, it is worthwhile to complement the experimental findings [1,[4][5][6][7][8][9] with appropriate theoretical simulations. We address this issue in the present paper, relying on the Boltzmann equation techniques and drawing attention to the possibility of new features of the DFG phenomenon in the millimeter wave band, which have not been discussed before.…”

“…We address this issue in the present paper, relying on the Boltzmann equation techniques and drawing attention to the possibility of new features of the DFG phenomenon in the millimeter wave band, which have not been discussed before. To illustrate this possibility, we consider, unlike the work cited above [1,[4][5][6][7][8][9], a graphene monolayer rather than few-layer graphene films and examine how its doping level, which can be changed flexibly via electrostatic gating, affects the DFG efficiency. Since monolayer graphene is a centrosymmetric material, the symmetry certainly has to be broken so that the DFG effect may arise due to the electricdipole-allowed process of three-wave mixing.…”