초록 ▼

An antenna used as a voltage and power source is designed to operate with arbitrary load, or front end. The antenna has one or more (number of) loading bars that are placed adjacent to the elements of the antenna at a spacing distance. The real part of the antenna input impedance is changed by adjus

An antenna used as a voltage and power source is designed to operate with arbitrary load, or front end. The antenna has one or more (number of) loading bars that are placed adjacent to the elements of the antenna at a spacing distance. The real part of the antenna input impedance is changed by adjusting the loading bar length, width, and/or spacing distance and/or the number of loading bars. These changes are implemented to reduce the real part of the antenna input impedance to make it small enough to develop an adequate voltage, Vp, to operated the front end and connected circuitry. In a preferred embodiment, the real part of the antenna input impedance is reduced to the point at which Vp no longer increases. One or more stubs is added to one or more of the antenna elements. The stubs act as two-conductor transmission line and is terminated either in a short-circuit or open-circuit. The short-circuit stubs act as a lumped inductor. The open-circuit stub acts as a lumped capacitor. The magnitude of these lumped capacitors and inductors (reactances) is affected by a stub length, a stub conductor width, and a stub spacing. Zero or more short-circuit stubs and zero or more open-circuit stubs are added to one or more of the antenna elements to change the reactive (imaginary) part of the antenna input impedance. In a preferred embodiment, the reactive part is changed to be equal to the negative magnitude of the reactive part of the front end input impedance. For a given real part of the antenna impedance, Ra, this approach maximizes both the DC voltage generated from the input and maximizes the power transferred between the antenna and the front end.

대표청구항 ▼

[ We claim:] [1.] An antenna for use as a power source with a load having a complex impedance comprising:a. an antenna section that has one or more elements and one or more antenna terminals, the antenna tuned to receive a radio frequency signal having a wavelength, an impedance across the antenna t

[ We claim:] [1.] An antenna for use as a power source with a load having a complex impedance comprising:a. an antenna section that has one or more elements and one or more antenna terminals, the antenna tuned to receive a radio frequency signal having a wavelength, an impedance across the antenna terminals having a real and a reactive part; andb. one or more loading bars, each loading bar having an effective length, the loading bar being within an antenna distance of at least one of the elements of the antenna over the effective length, the antenna distance being less than one quarter of the wavelength, and the loading bar reducing the real part of the impedance such that power delivered to the load by the antenna is increased.