A frequency modulated continuous-wave RF synthesiser based on a bandpass ΣΔ (BPΣΔ) direct digital frequency synthesised reference clock is presented. The synthesiser is fabricated using 0.13 µm CMOS process and measurement results show that, at the RF centre frequency of 2.3747 GHz, the chirp signal with chirp-rate of 10 kHz has a frequency linearity of 1% for frequency deviations up to 102 MHz. The measured phase noise of the radar synthesiser is −104 dBc at 1 MHz offset frequency.
