Harmonic and Intermodulation Performance of Quantum-Wire-Transistor (QWT) Based Inverting Amplifier
This paper presents a simple mathematical model for the gate-voltage/drain-voltage transfer characteristic of the quantum-wire transistor (QWT)-based inverting amplifier. The model, basically a Fourier cosine-series, yields closed-form expressions for the amplitudes of the harmonic and intermodulation components of the drain voltage resulting from a multisinusoidal gate voltage with a superimposed DC voltage. The special case of a two-tone equal-amplitude gate signal is considered in detail. The results show that the harmonic and intermodulation performance of the QWT based inverting amplifier is strongly dependent on the values of the superimposed DC voltage and the amplitudes of the input tones with either the second-order or the third-order intermodulation component dominating. The results also show that some of the harmonics and intermodulation products may exhibit minima at different values of the superimposed DC voltages and tone amplitudes.
Keywords: Quantum wire transistor, amplifier, harmonic, intermodulation