Extension of Non-Foster-inspired Two-transmitter Matching to Arbitrary Antenna Impedance

A broadband matching of a highly reactive small transmitting antenna is one of the most challenging applications of non-Foster elements. The difficulties are connected to the assurance of stable operation of negative impedance converter in environment with high-power signals. Recently, the instability-free approach that applies quadrature signals at a transmitting short dipole and mimics broadband cancellation with negative capacitor, has been demonstrated. Here, we propose an extension of this approach to emulation of negative inductance, as well as to the most general case of a complex matching with transformation of antenna radiation resistance. Theoretical analysis is complemented with several proof-of-concept experiments in 10-20 MHz HF band.