Multi-band linear chirp generation based on a type-III PLL

A type-III PLL is used to generate linear frequency ramps with 386 kHz RMS frequency error in L-band (3088 kHz in X-band) and 10% fractional bandwidth. Pulse durations can be as low as 10 μs without performance degradation. The system covers the L-, S-, C- and X-bands. A programmable output driver delivering −17.9 to +4.9 dBm differentially is included on chip. The system is fully integrated using a 250 nm SiGe BiCMOS process.