High order micro-strip filters to support signal generation and translation

A multi-band ultra-wideband channel sounder using baseband digital generation techniques in conjunction with heterodyne up-conversion and frequency multiplication to cover the two ISM bands has been developed at Durham University [1]. This paper describes a number of relatively high performance filters which have been developed to provide alias suppression for the sampled digital signal generation at baseband, image and local oscillator suppression for the heterodyne frequency up-converter for the first ISM band and fundamental and third harmonic suppression for signal multiplication for the second ISM band.