Integrated circuit field canceller system suitable for highly integrated connectivity transceivers

This paper presents, a coherent passive integrated system capable of cancelling out electro-magnetic coupling between integrated circuit inductors. Hence coupling-sensitive inductors such as VCO inductor could be brought close to a transmitter inductor with reduced VCO pulling effects. This in turn enables the use of free running VCO, and hence removes the overhead PLL power consumption, making this technique very suitable for ultra-low power applications. Initial simulation results are presented and cross verified with measurement from a 40nm process node. Measured data confirms Tx to VCO coil coupling reduces by more than 30dB. Also, free running VCO pulling experiments conducted on a Bluetooth transceiver chip clearly show that the proposed field cancellation system reduces the VCO pulling by a factor of four.