Patent ID: 8988173
Filing Date: 2015-03-24
Classification: H03F,H03H,H04B

Abstract:
1. A non-Foster circuit comprising: two differential pairs of transistors that are cross-coupled, each transistor of said two differential pairs of transistors having a pair of current carrying electrodes and a control electrode, the control electrodes of the transistors in a first one of said two differential pairs of transistors being coupled to one of the current carrying electrodes of the transistors in a second one of said two differential pairs of transistors, the control electrodes of the transistors in the second one of said two differential pairs of transistors being coupled to one of the current carrying electrodes of the transistors in the first one of said two differential pairs of transistors; a load immittance coupled to one of the current carrying electrodes of each of the transistors in said first one of said differential pair of transistors and a first control resistance coupled to another one of the current carrying electrodes of each of the transistors in said first one of said differential pair of transistors; current sources for supplying a flow of current to at least one of the current carrying electrodes of each of the transistors in said two differential pairs of transistors; two common-mode feedback networks, each common-mode feedback network being coupled to current carrying electrodes of the transistors of one of the two differential pairs of transistors; and terminals across which a desired immittance is generated, the terminals being coupled to one of the current carrying electrodes of each of the transistors in said second one of said differential pair of transistors and a second control resistance coupled to another one of the current carrying electrodes of each of the transistors in said second one of said differential pair of transistors, a function based at least in part on a product of the resistances of the first and second control resistances setting a conversion ratio between the load immittance and the desired immittance.