Systems and methods for beam enhancement

Abstract

Beam enhancement through sidelobe reduction and/or mainlobe sharpening is shown. Embodiments utilize dynamic resolution, improved dynamic resolution, and/or enhanced dynamic resolution techniques to synthesize beams, such as ultrasonic beams used in ultrasonic imaging, having desired attributes. Embodiments simultaneously form a first sample beam and a second or auxiliary sample beam for every sample to synthesize enhanced scan beams. According to a dynamic resolution techniques herein a new beam may be formed from the sum of the two sample beams. A synthesized dynamic resolution beam of embodiments has reduced sidelobes with relatively little or no spread of the mainlobe. An enhanced dynamic resolution beam sharpening function can be applied to provide a further enhanced beam, such as to further narrow the mainlobe.

We claim: 
     
         1 . A method comprising:
 segmenting a beam signal into a mainlobe component and a sidelobe component;   applying a beam sharpening function to the mainlobe component; and   recombining the mainlobe component and the sidelobe component after application of the beam sharpening function to the mainlobe component.   
     
     
         2 . The method of  claim 1 , wherein the beam sharpening function comprises:
 subtracting a weighted component of a sample beam signal from the mainlobe component.   
     
     
         3 . The method of  claim 2 , wherein the subtracting the weighted component of the sample beam signal comprises:
 taking a minimum of the weighted component of the sample beam signal and the mainlobe.   
     
     
         4 . The method of  claim 2 , wherein the subtracting the weighted component of the sample beam signal comprises:
 iteratively subtracting differently weighted sample beam components from the mainlobe component.   
     
     
         5 . The method of  claim 2 , wherein the weighted component of the sample beam comprises a weighted mainlobe component. 
     
     
         6 . The method of  claim 2 , wherein the sample beam comprises a signal provided by an apodized beam. 
     
     
         7 . The method of  claim 6 , wherein the apodized beam comprises an apodized cosine beam. 
     
     
         8 . The method of  claim 1 , wherein the recombining the mainlobe component and the sidelobe component comprises:
 combining a non-null sidelobe component with the mainlobe component.   
     
     
         9 . The method of  claim 1 , wherein the beam signal which is segmented into the mainlobe component and the sidelobe component is provided by a synthesized beam technique. 
     
     
         10 . The method of  claim 9 , wherein the synthesized beam technique comprises:
 segmenting a first beam signal into a mainlobe component and a sidelobe component;   independently processing at least one of the mainlobe component and the sidelobe component; and   recombining the mainlobe component and the sidelobe component as independently processed.   
     
     
         11 . The method of  claim 9 , wherein the independently processing at least one of the mainlobe component and the sidelobe component comprises:
 weighting the at least one of the mainlobe component and the sidelobe component differently than the other one of the mainlobe component and the sidelobe component.   
     
     
         12 . The method of  claim 11 , wherein the weighting the at least one of the mainlobe component and the sidelobe component differently comprises:
 weighting the sidelobe component to have a lesser weighting than a weighting of the mainlobe component for the recombining.   
     
     
         13 . The method of  claim 9 , wherein the synthesized beam technique comprises:
 obtaining a first signal using a first sample beam having a first mainlobe and one or more sidelobe;   obtaining a second signal using a second sample beam having a second mainlobe and one or more sidelobe, wherein a shape of the first mainlobe is substantially different than a shape of the second mainlobe; and   synthesizing a beam to provide the beam signal using the first signal and the second signal and a weighting factor.   
     
     
         14 . The method of  claim 13 , wherein the first sample beam comprises an unapodized beam and the second sample beam comprises an apodized beam. 
     
     
         15 . The method of  claim 14 , wherein the first sample beam comprises a Sinc beam and the second sample beam comprises a cosine apodized beam. 
     
     
         16 . The method of  claim 13 , further comprising:
 selecting the weighting factor to provide the synthesized beam having one or more reduced sidelobe as compared to the first and second sample beams.   
     
     
         17 . The method of  claim 16 , wherein the selecting the weighting factor further comprises:
 selecting the weighting factor to provide an acceptable balance between the reduced sidelobe of the synthesized beam and increased mainlobe width as compared to the first sample beam.