Ltcc Broadband Miniaturization 180 ° Research Design Of The Bridge

180°hybrid is a fundamental component in microwave circuits as it performs important functions of "Sum" and "delta". It is one of the most important components in the single pulse feed network. Moreover, it can also be used in balanced mixers and power amplifiers. Today, miniaturization and integration are the trend of the wireless communication industry. So, miniaturization of internal components is particularly important. However, LTCC is becoming a pivotal technology in this trend of miniaturization for its cascading embedded function. LTCC products design needs to follow some design principles. These design principles are introduced in the paper, based on which a broadband compact180°hybrid and its components are designed.In this paper, the bridge is divided into two parts to study which are the in-phase part and the out-of-phase part. In the in-phase part, we firstly discuss the design methods of inductors and capacitors, mainly through the equivalent circuit analysis and parameter extraction. By using parameter scanning, the influence of effective value of inductors and capacitors are analyzed. Meanwhile, we get some design rules for the circuit debugging to provide a reference for the following study. According to the method, a5.6nH inductor and1.1pF capacitor used in the hybrid are designed.As to the out-of-phase part of hybrid, a spiral board-side coupling Marchand balun is used. Capacitance compensation is utilized to improve the output balance and the phase differences of the Marchand balun.Finally, incorporating the in-phase and out-of-phase parts, a semi-lumped180°hybrid working in1.5～2.5GHz is presented, according to the principles introduced in chapter two. Simulation result shows that the relative bandwidth of180°hybrid is about50%. It achieves excellent amplitude and phase balance. Most of the results can reach the targets.