Injection locked oscillators for quadrature generation at radio frequency

The design of quadrature signal generators is one of the most challenging issues in modern RF transceivers. After a brief review of conventional techniques, this paper presents injection locked oscillators as a viable alternative to achieve high performance and low power consumption. Two different architectures, realized in a 0.18 μm CMOS technology, are presented and compared. The first shows excellent driving capability and simple design, the second lends itself to low power operation.