This technology is a novel design for highly balanced quadrature signal generation on integrated circuits across millimeter (mm) wave frequencies. Georgia Tech’s innovation enhances the phase and the amplitude matching of quadrature signals with lower insertion loss over broader bandwidth than is possible with conventional polyphase quadrature generation methods. The network also has reduced sensitivity to process variations compared to these methods, and each stage of the network enhances the image rejection ratio (IRR). These advances over other quadrature generation methods make it a promising solution for mm-wave applications, as it eliminates the need for extra calibration and tuning.

Georgia Tech’s network employs two couplers to generate narrowband in-phase/quadrature (I/Q) signals, which are then applied to a quadrature-hybrid ring (QHR) that combines the signals and compensates their quadrature errors. This provides I/Q signals over a broad bandwidth. The network can cascade several QHR stages to provide more balanced I/Q signals. Phase matching at mm-wave frequencies is challenging, since any small length mismatch in the layout will introduce a large phase error. Therefore, a symmetric implementation is essential for providing highly balanced signals at these frequencies. Georgia Tech’s innovation addresses this challenge with a design that features a common centroid layout for the QHR and the core transistors to provide accurate quadrature signals. Compared to available calibration techniques, this method is more efficient due to superior linearity, frequency scalability, design simplicity, and zero static-power consumption.