In signal processing, the main lobe width refers to the width of the central peak of the frequency response of a [[window function]], which determines the frequency resolution of a windowed signal. The main lobe width is usually measured as the Full Width at Half Maximum (FWHM), which is the width of the main lobe at half of its maximum amplitude. A narrower main lobe width indicates higher frequency resolution and better ability to distinguish closely spaced frequencies, while a wider main lobe width indicates lower frequency resolution and potential interference between closely spaced frequencies. The main lobe width is one of the [[spectral features of window functions]].