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 triband 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 fo, fo/2 and 2xfo, with maximum frequency of 36 GHz, 18 GHz and 72 GHz respectively. The system which is implemented in a 0.25-mu m 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 fo-port. All outputs have a tuning range of 9.5%. The in-band output power at the fo, fo/2 and 2xfo outputs is higher than 3 dBm, 0 dBm and -20 dBm respectively. The whole system draws 120 rnA for a power supply of 2.5 V.