The Realizability of Multiport Structures Obtained by Imbedding a Tunnel Diode in a Lossless Reciprocal Network

It is generally well known that, the tunnel diode possesses a smallsignal equivalent circuit that can often be approximated by a parallel combination of a capacitor and a negative resistor. This model has been used extensively in the study of gain-bandwidth relations and optimum synthesis procedures for specific amplifier configurations. 1 " 5 It has also been used to derive bounds on the natural frequencies obtained by imbedding the tunnel diode in a passive network. 6 - 7 The purpose of this paper is to present necessary and sufficient conditions for the realization of the short-circuit admittance matrix or opencircuit impedance matrix of the most general n-port structures characterized by such matrices obtained by imbedding a tunnel diode, represented by the above mentioned model, in a lossless reciprocal network. The properties of the short-circuit admittance matrix are considered also by another writer. 8 With the exception of certain remarks of a tutorial nature, the arguments, results, synthesis techniques, and basic approach to the problem presented here are quite different from that in lief. 8. In particular, it is not assumed here that the short-circuit admittance matrix of the (n + l)-port lossless network invariably exists. 857