A broadband compound waveguide lens which is the analog of the optical achromatic doublet is described and analyzed for its phase error characteristics. The bandwidth over which the aperture phase error remains less than

is shown to vary from 40 to 20 percent for lens diameters varying from 20 to 100 wavelengths. This is an order of magnitude greater than the bandwidth heretofore obtainable with conventional waveguide lenses.