Influence of substrate noise on RF performance

A low-ohmic substrate 0.25µm CMOS process has been chosen to carry out experiments to measure the effects of substrate noise on the performance of circuits operating at radio frequencies. Clock circuits give rise to substrate noise with spectral harmonics far into the RF band. These harmonics are injected into the signal path of RF circuitry as will be demonstrated. Clock planning is therefore a major issue in mixed-signal telecommunication.