Alfred Ira Grayzel, (Park City, UT) and Ashok Gorwara, (New Market, MD) have been granted a US patent for “Very Narrowband and Wideband Negative Resistance Amplifiers with a Tunable Center Frequency using a Coupler.” They worked on this technology for ten years and are hoping that someone will use and apply the invention in various types of communications systems and cell phones where high fidelity and low noise performance is required in a very crowded & busy signal environment.
The patent is a negative resistance amplifier including a negative resistance network where the negative resistance network may be any known circuit element characterized by a negative ratio of the voltage a between its output terminals and to the current flowing through the element: a reactance network resonant at the center frequency of the amplifier where the reactive network may contain a varactor for tuning of the resonant frequency of the reactance network: and a circulator whose port 1 is the input terminal of the amplifier, whose port 3 is the output port of the amplifier and whose port 2 is connected to the combination of the negative resistance network and the reactance network.