A novel 245 GHz 4thindex push-push VCO

A novel 245 GHz 4
^th
index harmonicpush-push VCO is presented in IHP SiGe: C BiCMOS technology with f
_T
and f
_max
of 300 and 500 GHz respectively. The VCO utilizes the 4
^th
harmonic index in the push-push oscillating core to obtain 245 GHz signals. The VCO comprises of a 4
^th
harmonic oscillating core with 1/64 divider and a 245 GHz common base (CB) LNA buffer stage. The output power of the VCO reaches -18 dBmat 251 GHz with a phase noise of -86 dBc/Hz at 1 MHz offset frequency. The VCO has a tuning range of 18 GHz, occupies an area of 0.45 mm
²
and dissipates 179 mW with divider, or 95 mW without divider.