The design and measurement of a Local Oscillator Synthesiser Module for Broadband Applications is described. Broadband receivers require local oscillators whenever heterodyning is utilised in receiver architectures to convert frequency signal to an intermediate-frequency (IF) spectrum for ease of signal processing. Frequency converters are employed in microwave receivers and involve the interception and exploitation of signal across 2 to 18 GHz. The presentation describes the design and measured performance of a 3 to 7 GHz and 8 to 18 GHz COTS based local oscillator synthesiser module that exhibits low phase noise, low spurious levels and fast switching.