Design and analysis for three applications of 90-degree single balanced mixer

Three different types of 90-degree hybrid mixers were designed and analyzed in the ISM 2.4 GHz band. These are general type, low distortion type and size-reduced type. For low distortion type, the 1-dB compression point and 3^rd intercept point are increased about 3 dB. 90-degree single balanced mixer has a major shortcoming at 2.4 GHz frequency band with a significant penalty in board space. So another application for a small size 90-degree single balanced mixer was designed by using capacitor compensated method. The size-reduced type can save about 75% of circuit board size and achieve similar performances. In this paper, we will analyze the design concepts of these mixers and discuss the performances of each mixer.