Feedback Capacitors Based Signal Distributor Circuit

摘要

In this work, dynamic fine adjustment approach was applied to overcome signal skew for the circuits which use LC tank voltage-controlled oscillator (LCVCO) core elements as signal source. 2 different control voltages Vcon1, and Vcon2 were applied to variable oscillation tuning varactor capacitances and common resonance point. Roundtrip metal wire lines were used as signal distributor networks. Feedback capacitance values were dynamically changed depend on the output voltage of LCVCO. The advantage of using this method is to be able to adjust the concurrency of signal distribution between different nodes simultaneously. Signal skew annihilator feedback capacitors were connected to positive and negative outputs of the LCVCO. For the simplicity of the theory, 2 separate signal distribution wire paths were used. 65 nm CMOS RF technology was used, and signal skew was decreased down to 108 attosecond (as) time difference between 2 separate wire lines for 2 different nodes which their path resistance (R) and capacitance (C) were symbolically used in the simulation. LCVCO oscillation frequency is 43 GHz.