Universal linear voltage-controlled-impedance configuration

Introduces a new configuration that possesses the novel feature of realising positive as well as negative linear VCZs from the same structure by the simple artifice of changing only one interconnection, and hence can be called a universal VCZ configuration. Two different and separate structures for realising positive and negative linear VCZs are no longer required. The proposed configuration not only employs fewer components than previously reported VCZ structures but also is functionally more versatile than all of them