Transformer Coupled High-Density Circuit Technique for MMIC

A circuit technique that employs a transformer wrapped around an active device to increase circuit density has been demonstrated with key building blocks for sensor systems. This technique is completely compatible with planar fabrication processes used in the fabrication of high-density and high-yield circuits. Measured results from a wraparound transformer-FET combination are compared with a similar circuit that incorporates octagonal transformers. The wraparound technique has been successfully implemented in the design of a transmitter and an image reject mixer. Test results from these circuits are presented.