A robust low phase noise and wide tuning range Ku band sub-integer frequency synthesizer for E-band backhaul transceivers

This paper presents a Ku band sub-integer frequency synthesizer designed in IBM 0.13um SiGe BiCMOS8hp for E-band backhaul transceivers. To improve phase noise a Gm boosted Colpitts topology was used together with a 4 bit capacitor bank for wide tuning range. Utilizing a sub-integer phase rotating divider the synthesizer realizes 132 channels with a 27.78 MHz resolution, covering 15.583 - 19.11 when using a 55.56 MHz reference. Phase noise is lower than -133 dBc/Hz at 10MHz offset, while reference and sub-integer spurs are lower than -56dBc. The synthesizer is robust to temperature variation within -400C to 85°C.