Intrinsic phase noise properties and frequency stability of millimetre‐wave module at 90 GHz

A report is presented on the residual intrinsic phase noise properties of a millimetre‐wave module used to generate W‐band signals from an X‐band analogue signal generator. The 90 GHz outputs of two nominally identical millimetre‐wave modules are heterodyned to measure their instantaneous frequency fluctuations and hence infer the close‐to‐carrier phase noise. The fractional frequency stability at 1 s integration time is 2 × 10 −14 , which corresponds to a total single‐sideband phase noise of −50 dBc/Hz at 1 Hz Fourier frequency offset from the carrier and a residual single‐sideband phase noise of −52 dBc/Hz at 1 Hz offset.