Design and Implementation of Single-Layer Symmetric Micro-Transformers

In this paper, interleaved planar symmetric micro-transformers are implemented with single metal layer for the first time in the standard Metal-multi-user micro-electro-mechanical process (MUMP). Bonding wires are used for leading the inner terminal connections out to the outer terminal of the spiral square transformers. Two designs of micro-transformers with different dimensions are fabricated. The functionality of the devices was tested for very high frequency and ultra high frequency ranges using cascade ground signal ground probes and compared with the simulation results. The maximum efficiency of 80.65% has been achieved by S1 micro-transformer design, and the maximum efficiency of S2 micro-transformer is 76.9% at 1 GHz. The total footprint of S1 and S2 designs is 1.32 and 0.37 mm(2), respectively.