Feed structure for a metamaterial antenna system

Abstract

The present invention is an antenna system having an array of metamaterial cells and a transmission array having a plurality of slots, wherein a signal propagates through the transmission array to the metamaterial cells and radiates a beamform. The system further includes reactance control means to adjust a phase of the beamform and to perform beam steering and beam switching.

1 . A radar system, comprising:
 a metamaterial antenna structure, comprising:
 an array of metamaterial unit cells, each unit cell having a reactance control means, the array of metamaterial unit cells configured to radiate a beamform; and 
 a transmission array communicatively coupled to the array of metamaterial unit cells, the transmission array comprising a plurality of discontinuities, wherein signals propagating through the plurality of discontinuities form electromagnetic radiation transmissions that radiate onto the array of metamaterial unit cells; and 
   an antenna controller coupled to the reactance control means and adapted to adjust an effective reactance of the array of metamaterial unit cells to form the beamform having an adjusted phase.   
     
     
         2 . The radar system of  claim 1 , wherein the transmission array includes a plurality of transmission lines, each transmission line of the plurality of transmission lines having one or more discontinuities of the plurality of discontinuities positioned along its length. 
     
     
         3 . The radar system of  claim 2 , wherein the one or more discontinuities are positioned as a function of a desired radiation pattern. 
     
     
         4 . The radar system of  claim 1 , wherein the antenna controller is further adapted to adjust beamform phases and to scan a field of view. 
     
     
         5 . The radar system of  claim 1 , wherein the reactance control means comprises a varactor, and the effective reactance includes capacitance. 
     
     
         6 . The radar system of  claim 1 , further comprising:
 a feed network coupled to the transmission array and comprising phase adjust means.   
     
     
         7 . A radar system, comprising:
 an array of unit cells;   an array of super elements; and   a feed structure comprising:
 an input port; 
 a distributed feed network of transmission lines configured to divide a signal received at the input port; and 
 a transmission array coupled to a side of the distributed feed network. 
   
     
     
         8 . The radar system of  claim 7 , wherein the array of unit cells, the array of super elements, and the feed structure are arranged in different layers within the radar system. 
     
     
         9 . The radar system of  claim 7 , wherein the transmission array comprises a plurality of transmission lines having a plurality of discontinuities positioned along a length of the plurality of transmission lines. 
     
     
         10 . The radar system of  claim 9 , wherein the transmission array is configured to form an electromagnetic radiation transmission that radiates onto the array of unit cells when the signal propagates through the plurality of discontinuities. 
     
     
         11 . The radar system of  claim 9 , wherein the discontinuities are slots in a conductive portion of the feed structure and wherein a plurality of irises is positioned relative to at least one of the slots. 
     
     
         12 . The radar system of  claim 7 , further comprising:
 a transceiver module coupled to the feed structure; and   an object detection module coupled to the transceiver module and adapted to detect an object in a field of view of the radar system as a function of received signals.   
     
     
         13 . The radar system of  claim 12 , wherein the object detection module comprises an artificial intelligence (AI) module adapted to classify a detected object. 
     
     
         14 . A radar system, comprising:
 a transceiver module comprising an array of unit cells configured to transmit radio frequency (RF) signals;   an array of super elements coupled to the transceiver module; and   a feed structure coupled to the transceiver module via the array of super elements, the feed structure comprising a distributed feed network of transmission lines configured to divide a signal received at an input port.   
     
     
         15 . The radar system of  claim 14 , further comprising:
 a transmission array coupled to the distributed feed network on a first side of the transmission array, wherein the transmission array is further coupled to a second distributed feed network on a second side of the transmission array.   
     
     
         16 . The radar system of  claim 15 , wherein the transmission array comprises by a plurality of vias defining the transmission lines of the distributed feed network. 
     
     
         17 . The radar system of  claim 14 , wherein the RF signals comprise frequency modulated continuous wave (FMCW) signals, the radar system further comprising:
 a receiver configured for receiving the FMCW signals, the receiver comprising a mixer configured to compare transmitted FMCW signals to the received FMCW signals.   
     
     
         18 . The radar system of  claim 14 , further comprising:
 a reference substrate layer; and   a dielectric layer positioned between the feed structure and the reference substrate layer.   
     
     
         19 . The radar system of  claim 14 , wherein the array of unit cells is approximately perpendicular to the distributed feed network. 
     
     
         20 . The radar system of  claim 14 , wherein the array of unit cells is approximately parallel to the distributed feed network.