Active balun circuits for WiMAX receiver front-end

In this paper, three active balun circuits were designed and implemented in a standard 90nm CMOS process namely: (1) common-gate with common-source; (2) differential; and (3) common-source/drain. The active balun designs were intended for Worldwide Interoperability for Microwave Access (WiMAX) applications operating at frequency 5.725-5.825GHz. Measurements were taken for parameters such as gain difference, phase difference, and noise figure. All designs achieved gain difference of less than 1.8dB, phase difference of 180°±10°, and noise figure of around 7.5×12.4dB, which are comparable to previous researches. Low power consumption of at most 3.6mW was achieved.