Retrodirective wireless device and method
AssigneeNorbit ITS
InventorSteffen Kirknes
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Abstract
Present invention is a wireless device comprising a Van Atta array, said Van Atta array comprising a plurality of antenna pairs, each of said antenna pairs comprising two antenna elements electrically coupled by a signal path of pre-determined length. The wireless device further comprises a measurement unit, said measurement unit is adapted to perform electrical measurements between two measurement points. One of said two measurement points is located at a first pre-determined location on the signal path of one of the antenna pairs, and the other of said two measurement points is located on a second pre-determined location on the signal path of one of the other antenna pairs. The present invention is also a method for retro-reflection of an incident wave using a plurality of antenna pairs.
Claims11
A wireless device comprising:
- a Van Atta array, the Van Atta array comprising a plurality of antenna pairs;
- each of the antenna pairs comprising two antenna elements electrically coupled by a signal path of predetermined length;
- the signal path of each of the antenna pairs having a center point around which the two electrically coupled antenna elements are symmetrically arranged, wherein the wireless device further comprises a measurement unit, the measurement unit adapted to perform electrical measurements between two measurement points, one of the two measurement points being located at a first predetermined location on the signal path of one of the antenna pairs, and the other of the two measurement points being located on a second predetermined location on the signal path of one of the other antenna pairs;
- wherein the measurement unit comprises a directional coupler;
- wherein the directional coupler is a quadrature hybrid;
- and
- wherein a first port of the quadrature hybrid is coupled to a first antenna element of one of the antenna pairs of the Van Atta array, a second port of the quadrature hybrid is coupled to a second antenna element of the one of the antenna pairs of the Van Atta array, and wherein the wireless device further comprises a first diode and a second diode, the first diode being coupled to a third port of the quadrature hybrid, and the second diode being coupled to a fourth port of the quadrature hybrid.
A method for retro-reflection of an incident wave using a plurality of antenna pairs, wherein the steps performed in at least two of the antenna pairs in the plurality of antenna pairs, the method comprising:
- receiving an electromagnetic wave incident at the plurality of antenna pairs, resulting in a first received signal in a first antenna pair, and a second received signal in a second antenna pair, the first antenna pair and the second antenna pair being amongst the plurality of antenna pairs;
- measuring a first electrical signal at a first position on the signal path of the first antenna pair, the first position being at a first distance from the center point of the signal path of the first antenna pair;
- measuring a second electrical signal at a second position on the signal path of the second antenna pair, the second position being at a second distance fron the center point of the signal path of the second antenna pair;
- the second distance being non-equal to the first distance;
- generating a third signal by combining the first electrical signal and the second electrical signal;
- and
- using the third signal for finding the angle of travel the incident wave with respect to a reference line.
Dependencies are inferred from the claim text.