Modeling of the seven-terminal transformer implemented in the LTGC-QO

Resumo

In this paper a seven-terminal transformer has been designed. We have suggested its equivalent-circuit model. This transformer has a primary coil with a center tap and two secondary coils. Based on this transformer, a low-cost transformer-based gate-coupled quadrature oscillator (LTGC-QO) using 0.18 µm CMOS technology has been developed. The LTGC-QO consumes 7 mW at 1 V power supply. The simulated phase noise at 1 MHz offset is–116.3 dBc/Hz. The chip area is 400×500 µm.