Abstract
Designing beampatterns with constant beamwidth over a wide range of frequencies is useful in many applications in speech, radar, sonar and communication. In this paper, we design constant-beamwidth beamformers for concentric ring arrays. The proposed beamformers utilize the circular geometry to provide improved beamwidth consistency compared to beamformers which are designed for linear sensor arrays of the same order. In the proposed configuration, all sensors on each ring share the same weight value. This constraint significantly simplifies the beamformers and reduces the hardware and computational resources required in a physical setup. Furthermore, a theoretical justification of the beamforming method is provided. We demonstrate the advantages of the proposed beamformers compared to the one-dimensional configuration in terms of directivity index, white noise gain and sidelobe attenuation.
Highlights
Beamforming with Concentric RingApplications in communication, radar and speech processing require dealing with broadband signals [1]
To avoid non-uniform attenuation and distortion caused by the beamformer, several approaches implementing frequency invariant beamformers were presented in the literature [4,5,6,7,8,9,10,11,12]
The white noise gain (WNG) is a measure of the array gain in a spatially uncorrelated noise environment, which is a good indicator of the performance robustness to sensor imperfections
Summary
Applications in communication, radar and speech processing require dealing with broadband signals [1]. A post-summation normalization is applied to the output result, so the gain at all the frequencies is constant This method showed better sidelobe attenuation and robustness to array mismatches compared to other methods. We introduce a design method in the low frequency range that modifies the filters applied to each array element from lowpass filters to bandpass filters This method exploits the circular geometry and results in better performance compared to beamformers that are designed for ULA with an equivalent number of channels (i.e., beamformer order).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
