Beamforming is a signal processing technique that can be used in sensor arrays. It is commonly found in antenna diversity arrays and involves setting up the necessary equipment at specific angles so that certain signals experience constructive interference while others experience destructive interference. It can create this spatial selectivity in either the transmitting or receiving end of an array. Read on to learn more about this useful process and how the professionals implement it into arrays.
The most common type of beamforming uses electromagnetic frequencies to change the directionality of a signal by controlling the phase and amplitude at a transmitter or receiver to create constructive and destructive interference. This is useful because it allows the desired information to be gathered from signals and observed.
While sonar beamforming is similar to its electromagnetic counterpart, there are some key differences in how it is implemented, such as using a beamformer combiner. After all, sonar arrays range from 1 Hz to 2 MHz, and the size and spacing of the antennas can be vastly different for each setup. This means that the demands for the system shift to hardware at the beginning of the reception and transmission process, such as digitizers, amplifiers, and transducers. Additionally, the power of the cameras and sonars put extra strain on these systems that the beamforming equipment must handle.
The most common and simple type of beamformer is known as the delay-and-sum. With this version, all the weights of the antenna elements have equal magnitude. The necessary phases are selected in each antenna to turn the beamformer to the specified direction. Based on correlation and interference, this type of beamformer will have a changing noise-to-signal ratio.
One downfall of the delay-and-sum beamformer is that it uses multiple microphones to localize sources of sounds. That creates a problem because adjusting the direction of the beamformer changes its performance in an unpredictable way. Additionally, the number of microphones makes it hard to predict a configuration that will work best for your array.
That has led to the use of genetic algorithms to create evolved beamformer technology. These devices search an array for the best microphone configuration to get the highest noise-to-signal ratio. The only drawback to this type of device is that the number of configurations most evolved devices can detect has a limit of about 30 million.
There are several types of beamforming methods and equipment. Learning more about these can help you understand what the professionals are talking about when discussing beamformer technology.