Design of a novel circulator for wireless transceivers

A novel three port active circulator is proposed. The proposed circulator is composed of a phase divider with one transistor only, and a special form of Wilkinson power splitter operating as a power combiner. The circulator has been employed in FMCW radar front end with one antenna for both transmission and reception purposes. However, it can be used in other wireless communication transceivers. The circulator is designed and optimized at a center operating frequency of 2.45 GHz. Circulator simulations report good isolations for S₁₂ = -34 dB, S₃₁ = -24 dB, and S₁₃ = -13 dB with superior return losses for S₁₁ = -48 dB, S₂₂ = -25 dB, andS₃₃ = -51 dB.