  This work presents a small-signal high-frequency (HF) equivalent circuit (EC)
to model AC performances of black-phosphorous field-effect transistors
(BPFETs). The proposed EC is able to describe correctly both the experimental
HF intrinsic and extrinsic figures of merit, as well as S-parameters, from
different BPFET technologies. Single- and double-stage radio frequency gain
amplifiers, are designed at 2.4 GHz using the experimentally-calibrated
small-signal BPFET EC. Results show high-gain high-selective BPFET-based
amplifiers.
