Microphone Array Beamforming

This section contains a collection of pages that provide an introduction to beamforming. Beginners should start with the page on Delay Sum Beamforming. The other pages provide supporting material for this page.

	Delay Sum Beamforming The Delay Sum structure is the most basic form of beamformer. This is the place to start for an introduction to the field of beamforming.
	3D Coordinates The 3D coordinate system used for the beamforming pages on this site.
	Composite Arrays The composite or nested array is a simple approach of improving frequency invariance. It comprises multiple arrays of varying quantity and spacing of elements, each designed to provide a set main lobe beamwidth for successive frequency bands.
	Delay Calculation A fundamental part of beamforming is calculating the differences in wave arrival time between array elements. This page describes how to calculate the time difference between a plane wave front arriving at an array element and an arbitrary reference point.
	Fractional Delays Steering the mainlobe of a microphone array normally requires delaying the incoming sampled data with sub-sample accuracy. This page describes how this may be achieved.
	Microphone Preamplifier This page includes details of a microphone preamplifier that can be used to build a microphone array. Each amplifier can be used with a small electret condenser capsule and provides a line level output for direct connection to a ADC.
	Wave Summation A basic overview of the maths involved in adding sinusoidal signals. This forms a central part of analysing a beamformer's spacial response.