Non-foster impedance design techniques for high performance small antenna

The non-Foster impedance circuits enhance the bandwidth performance of small antennas. This paper explores various conventional and novel techniques to realise non-Foster impedance and conclude their advantages as well as limitations. These design techniques includes conventional operational amplifiers (op-amps) and bipolar junction transistors (BJTs) and non-conventional graphene field-effect transistors (GFETs) and resonant tunnelling diodes (RTDs). This paper facilitate the designer to select the appropriate non-Foster circuit (NFC) for broadband matching of antenna.