Design and practice of integrated assembly [microstrip coupler and balanced mixer]

This paper first discusses the possibility of realizing the multi-output of a microstrip directional coupler and the measures that have been taken to improve its properties. Then it sets out the impedance relation between the main line and the branch line of the 3 dB bridge of a microstrip balanced mixer. Finally, it introduces the experimental methods and results in the S band. In modern airborne radar systems, the microwave system is developing in the direction of small-size, automation, large-scale integration, wide band, low noise and high reliability. To meet the needs of modern microwave drivers, we have designed and manufactured a 2.5 GHz microwave integration assembly. This assembly consists of three microstrip isolators, coupler and a balanced mixer. Not only is it small, light and with wide bandwidth but also it easily provides terminals for measuring signals. This paper mainly demonstrates the design method of a microstrip line coupler with a 3-ended output and the impedance relation between the main line and the branch line of the balanced mixer and it also introduces the experimental results of the integrated assembly.