A low phase noise tri-band LO generation for Ku and E band radios for backhauling Point-to-Point applications

This paper demonstrates a fully integrated tri-band LO generation system based a low phase noise 12 GHz sub-harmonic VCO and an injection locked frequency tripler (ILFT) as the signal source. The system generates simultaneously three outputs at f₀, f₀/2 and 2×f₀, with maximum frequency of 36 GHz, 18 GHz and 72 GHz respectively. The system which is implemented in a 0.25-μm SiGe:C BiCMOS technology, has a phase noise of -107.72 dBc/Hz at 1 MHz offset from the 36 GHz signal measured at the f₀-port. All outputs have a tuning range of 9.5% The in-band output power at the f₀, f₀/2 and 2×f₀ outputs is higher than 3 dBm, 0 dBm and -20 dBm respectively. The whole system draws 120 mA for a power supply of 2.5 V.