Systems and methods for mitigating multipath radio frequency interference
AssigneePurdue Research Foundation
InventorJohn H. Mott
Life of this patent
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Abstract
A radio frequency transmission system and methods for mitigating multipath radio frequency interference are disclosed. Embodiments include a first helical antenna having a first radius and operable to receive a first electromagnetic signal, and a second helical antenna having a second radius and operable to receive a second electromagnetic signal. Further embodiments include a phase adjuster configured to receive the first electromagnetic signal as an input signal, apply an adjustable phase delay to the input signal, and output an adjusted electromagnetic signal. Still further embodiments include a signal combiner configured to receive the adjusted electromagnetic signal and the second electromagnetic signal and output a combined electromagnetic signal.
Claims19
A system for recovering transmitted radio frequency power lost to multipath interference, comprising:
- a first helical antenna defining a first circumference defining a first radius, wherein the first helical antenna is operable to receive a first electromagnetic signal;
- a second helical antenna defining a second circumference defining a second radius, wherein the second helical antenna is operable to receive a second electromagnetic signal;
- a phase adjuster operatively coupled to the first helical antenna and configured to
- receive the first electromagnetic signal as an input signal,
- apply an adjustable phase delay to the input signal, and
- output an adjusted electromagnetic signal;
- and
- a signal combiner operatively coupled to the phase adjuster and the second helical antenna and configured to
- receive the adjusted electromagnetic signal and the second electromagnetic signal,
- combine the adjusted electromagnetic signal and the second electromagnetic signal, and
- output a combined electromagnetic signal;
- wherein one of the first radius and the second radius is greater than the other of the first radius and the second radius;
- and
- wherein the system is configured to boost power of a transmitted signal from a transmitter, wherein the first electromagnetic signal and the second electromagnetic signal originate from the transmitted signal, and wherein the second electromagnetic signal is a resultant wave of multipath interference relative to the first electromagnetic signal.
A method for mitigating multipath radio frequency interference of a transmitted signal from a transmitter, comprising the steps of:
- receiving a primary electromagnetic signal originating from the transmitted signal with a first helical antenna, wherein the first helical antenna includes a first wire conductor for the receiving of the primary electromagnetic signal and the primary electromagnetic signal is circularly polarized;
- receiving a secondary electromagnetic signal originating from the transmitted signal with a second helical antenna, wherein the second helical antenna includes a second wire conductor for the receiving of the secondary electromagnetic signal, the first wire conductor and the second wire conductor are contra-wound, and the secondary electromagnetic signal is a resultant wave of multipath interference relative to the primary electromagnetic signal and is circularly polarized and is a phase-shifted variant of the primary electromagnetic signal;
- applying a phase delay to the secondary electromagnetic signal and outputting a phase-adjusted electromagnetic signal;
- combining the phase-adjusted electromagnetic signal with the primary electromagnetic signal and outputting a resultant signal;
- and
- boosting the power of the transmitted signal from the transmitter.
An apparatus for receiving transmitted radio frequency signals, comprising:
- a first concentric cylinder having a first circumference defining a first radius and a first length;
- a second concentric cylinder having a second circumference defining a second radius and a second length, wherein the first radius of the first concentric cylinder is greater than the second radius of the second concentric cylinder, the second concentric cylinder is positioned inside the first concentric cylinder, and the first length is equal to the second length;
- a first conductive wiring wound around the first concentric cylinder in a first direction, wherein the first conductive wiring is operable as a first antenna for receiving a first electromagnetic signal;
- and
- a second conductive wiring wound around the second concentric cylinder in a second direction, wherein the second conductive wiring is operable as a second antenna for receiving a second electromagnetic signal, wherein the second direction is opposite to the first direction;
- wherein the apparatus is configured to boost power of a transmitted signal from a transmitter, wherein the first electromagnetic signal and the second electromagnetic signal originate from the transmitted signal, and wherein the second electromagnetic signal is a resultant wave of multipath interference relative to the first electromagnetic signal.
Dependencies are inferred from the claim text.