Filtering Undesired Polarization of Signals Transmitted From A Chip To A Waveguide Unit

Abstract

A communication system is disclosed. The system may include an antenna unit having a port. The system may also include a communication chip communicably coupled to the antenna unit and having an antenna configured to transmit electromagnetic signals into the port. In addition, the system may include a slotted structure configured for receiving the electromagnetic signals from the antenna and coupling the electromagnetic signals from the antenna into the port.

What is claimed is: 
     
         1 . A communication system comprising:
 an antenna unit having a port;   a communication chip communicably coupled to the antenna unit and having an antenna configured to transmit electromagnetic signals having a desired polarization and an undesired polarization;   a waveguide communicatively coupled between the communication chip and the port and configured to propagate the electromagnetic signals from the antenna towards the port; and   a slotted structure, physically separate from the waveguide, and configured for receiving the electromagnetic signals from the waveguide, removing the undesired polarization from the electromagnetic signals, and coupling the electromagnetic signals having the desired polarization into the port.   
     
     
         2 . The communication system of  claim 1 , wherein the slotted structure is a physically distinct and separate component from the antenna unit. 
     
     
         3 . The communication system of  claim 2 , wherein the slotted structure is coupled between the port and the waveguide. 
     
     
         4 . The communication system of  claim 1 , wherein:
 the port of the antenna unit is located on a first surface of the antenna unit, and   a second surface of the antenna unit comprises at least one radar-transmission antenna.   
     
     
         5 . The communication system of  claim 1 , wherein:
 the waveguide comprises a waveguide chimney having a first end proximate to the communication chip and a second end opposite the first end and proximate to the port of the antenna unit, and   the slotted structure is located between the port and the second end of the waveguide chimney.   
     
     
         6 . The communication system of  claim 5 , wherein the waveguide chimney is a dual-channel waveguide chimney. 
     
     
         7 . The communication system of  claim 1 , wherein:
 the waveguide comprises a first section, a second section, and a rotary joint, and   the rotary joint comprises an air gap across which the electromagnetic signals propagate from the first section to the second section.   
     
     
         8 . The communication system of  claim 1 , wherein a target impedance matching characteristic determines a size and shape of a slot of the slotted structure. 
     
     
         9 . The communication system of  claim 1 , wherein the slotted structure comprises:
 a slot configured for receiving the electromagnetic signals from the waveguide and coupling the electromagnetic signals from the antenna into the port; and   one or more vias located proximate to a center of the slot, wherein the one or more vias are configured to induce the slot to radiate the electromagnetic signals into the port.   
     
     
         10 . A method for filtering out undesired polarizations from electromagnetic signals, the method comprising:
 coupling, from a waveguide, into a slotted structure, electromagnetic signals transmitted by an antenna of a communication chip toward a port of an antenna unit, wherein the antenna is configured to transmit the electromagnetic signals out of the communication chip and into the waveguide, wherein the antenna unit is communicatively coupled to the communication chip, wherein the electromagnetic signals transmitted by the antenna have a desired polarization and an undesired polarization, wherein the slotted structure is configured to couple electromagnetic signals having the desired polarization into the waveguide, and wherein the slotted structure and the waveguide are different structures; and   coupling, from the slotted structure, into the port of the antenna unit, the electromagnetic signals having the desired polarization, whereby the undesired polarization is removed and the electromagnetic signals leaving the slotted structure have the desired polarization.   
     
     
         11 . The method of  claim 10 , further comprising:
 before coupling the electromagnetic signals from the waveguide into the slotted structure, coupling the electromagnetic signals from the antenna through a first section of the waveguide, across a rotary joint separating the first section from a second section of the waveguide, and into the second section,   wherein the rotary joint comprises an air gap.   
     
     
         12 . The method of  claim 10 , wherein the slotted structure is a physically distinct and separate component from the antenna unit. 
     
     
         13 . The method of  claim 12 , wherein the slotted structure is coupled between the port and the waveguide. 
     
     
         14 . The method of  claim 10 , wherein:
 the waveguide comprises a waveguide chimney having a first end proximate to the communication chip and a second end opposite the first end and proximate to the port of the antenna unit, and   the slotted structure is located between the port and the second end of the waveguide chimney.   
     
     
         15 . The method of  claim 14 , wherein the waveguide chimney is a dual-channel waveguide chimney. 
     
     
         16 . The method of  claim 10 , wherein:
 the waveguide comprises a first section, a second section, and a rotary joint, and   the rotary joint comprises an air gap across which the electromagnetic signals propagate from the first section to the second section.   
     
     
         17 . The method of  claim 10 , wherein a target impedance matching characteristic determines a size and shape of a slot of the slotted structure. 
     
     
         18 . A communication system comprising:
 an antenna unit configured to radiate radar signals, wherein the antenna unit comprises:
 a plurality of transmission antennas arranged in an array, 
 a port configured to receive radar signals for radiation by the plurality of transmission antennas, and 
 a waveguide network coupling the port to the plurality of transmission antennas; 
   a communication chip communicably coupled to the port, wherein the communication chip is configured to radiate a radar signal having a desired polarization and an undesired polarization;   a waveguide communicatively coupled between the communication chip and the port; and   a signal-filtering slotted structure, different from the waveguide, and configured to receive the radar signal from the waveguide, filter the undesired polarization from the radar signal, and couple the filtered radar signal into the port.   
     
     
         19 . The communication system of  claim 18 , wherein a target impedance matching characteristic determines a size and shape of a slot of the signal-filtering slotted structure. 
     
     
         20 . The communication system of  claim 18 , wherein the communication system is a radar communication system coupled to an autonomous vehicle.