The design of a new spiral inductor balun used in RF/MW based on 0.13μm CMOS process

The design of a new broadband monolithic passive balun using planar-spiral inductor transformers structure is described. Operational frequencies of the range from 15 GHz to 40 GHz and the center frequency is about 20 GHz. The performance of the balun is simulated, and the results are: the single port power loss is less than 6 dB. The amplitude and phase unbalance are less than 0.5 dB and 5 degree, at 15-40 GHz frequency bandwidth, respectively.