Miniature High-integrated Ltcc Microwave Diplexer Research And Design,

At present, many communication systems use one common antenna for receiving and sending the signal, diplexer is the key device which divides the RF signal received or transmitted by antenna into different bands and then transport to the follow circuits. As the former part of the RF system, the performance of filters can directly affect the quality of the system. Now, Microwave diplexers are widely used in microwave and milimeter-wave communications, navigation, guidance, remote sensing, and military electronic war. And that leads to more and more stringent requirement for microwave diplexers. Diplexers with smaller insertion loss, wide band, high power handling, good spurious performance and high selectivity are becoming customer's favorite. Meanwhile, with the rapid development of the national economy and the rapid advance of national defense science and technology, aviation, aerospace, radar systems, individual soldier intelligent weapons and airborne radio system, etc. request high performance and miniaturization microwave devices.This thesis follow the guide of basic theory of microwave filter and diplexer, combine with the advanced LTCC technology, research into the design and miniaturization of diplexers, accomplished the design of two high quality, miniaturized diplexers. In this work, we proposed Equivalent Replacement Method creatively, successfully resolved the component realizing problem met during the design. This module hold a volume of 4.3 mm×3.2 mm×2.6 mm, working frequency band:0.2 GHz～0.75 GHz,0.95 GHz～1.45 GHz,1.65 GHz～2.15 GHz, as far as we know, such a small size microwave diplexer working in this band has not been seen civil before. The components were simulated and optimized by a full-wave three-dimension simulation software named HFSS (High Frequency Structures Simulator), provided by Ansoft corporation. To prove the efficiency of the design work, we make one of the design fabricated and measured, the measurement turned out to beyond the requirements, some of the specifications even excel the kindred product abroad.Considering highly integrated miniaturized diplexer with the difficulties to solve this study successfully resolved impedance matching and components realizing problems, achieved a diplexer working from 0.2 GHz to 2.15 GHz, the attenuation in the stop band is as much as 30dB, which are not only meaningful to LTCC diplexer implementation, but also worthy to be used as reference in other RF passive components integrated designs.