Patent application number | Description | Published |
20120256709 | Differential negative impedance converters and inverters with variable or tunable conversion ratios - A differential circuit topology that produces a tunable floating negative inductance, negative capacitance, negative resistance/conductance, or a combination of the three. These circuits are commonly referred to as “non-Foster circuits.” The disclosed embodiments of the circuits comprises two differential pairs of transistors that are cross-coupled, a load immittance, multiple current sources, two Common-Mode FeedBack (CMFB) networks, at least one tunable (variable) resistance, and two terminals across which the desired immittance is present. The disclosed embodiments of the circuits may be configured as either a Negative Impedance Inverter (NII) or a Negative Impedance Converter (NIC) and as either Open-Circuit-Stable (OCS) and Short-Circuit-Stable (SCS). | 10-11-2012 |
20120256811 | Widebrand Adaptable Artificial Impedance Surface - A tunable impedance surface, the tunable surface including a plurality of elements disposed in a two dimensional array; and an arrangement of variable negative reactance circuits for controllably varying negative reactance between at least selected ones of adjacent elements in the aforementioned two dimensional array. | 10-11-2012 |
20130009720 | WIDE BANDWIDTH AUTOMATIC TUNING CIRCUIT - An automatic tuning circuit for matching an antenna to a radio receiver. The automatic tuning circuit includes a tunable non-Foster circuit for coupling the receiver and the antenna; and sensing and feedback circuits for sensing the combined capacitance of the tunable non-Foster circuit and the antenna and for tuning the tunable non-Foster circuit to automatically minimize the combined capacitance of the tunable non-Foster circuit and the antenna. | 01-10-2013 |
20130009722 | WIDE BANDWIDTH AUTOMATIC TUNING CIRCUIT - An automatic tuning circuit for matching an antenna to a radio receiver. The automatic tuning circuit includes a tunable non-Foster circuit for coupling the receiver and the antenna; and sensing and feedback circuits for sensing the combined capacitance of the tunable non-Foster circuit and the antenna and for tuning the tunable non-Foster circuit to automatically minimize the combined capacitance of the tunable non-Foster circuit and the antenna. | 01-10-2013 |
20130009724 | NON-FOSTER CIRCUIT STABILIZATION METHOD - A method of and circuit for improving stabilization of a non-Foster circuit. The method comprises steps of and the circuit includes means for measuring a noise hump power at an antenna port or an output port of the non-Foster circuit, comparing the measured noise hump power with a desired level of noise power that corresponds to a desired operating state of the non-Foster circuit, and tuning the non-Foster circuit to generate the desired level of noise power to achieve the desired operating state of the non-Foster circuit. | 01-10-2013 |
20140300431 | Broadband non-Foster Decoupling Networks for Superdirective Antenna Arrays - A four port antenna decoupling network which has only two negative capacitors and four or more positive capacitors and a method of improving low frequency receiving performance of two element and four element antenna arrays using one or more wideband decoupling circuits wherein each of said wideband decoupling circuits contain a maximum of two non-Foster components, the two non-Foster components preferably simulating negative capacitors. | 10-09-2014 |
20150244079 | CAVITY-BACKED ARTIFICIAL MAGNETIC CONDUCTOR - An active artificial magnetic conductor includes an array of unit cells, each unit cell including a top face, at least one wall coupled to the top face, a base coupled to the at least one wall, and a crossed slot in the top face. The top face, the at least one wall, and the base form a cavity and are conductive. | 08-27-2015 |
20150244080 | POLARIZATION INDEPENDENT ACTIVE ARTIFICIAL MAGENTIC CONDUCTOR - An active artificial magnetic conductor includes a ground plane and an array of unit cells coupled to the ground plane. Each unit cell includes a low impedance shunt coupled to the ground plane and an impedance element coupled to the low impedance shunt. A plurality of non Foster circuits are coupled in two different directions between impedance elements of adjacent neighboring unit cells in the array of unit cells. | 08-27-2015 |