Microwave application of artificial dielectrics based on low temperature cofired ceramics configuration (LTCC)

1.基于人工介质概念的多层叉指谐振器将以小型化、低损耗和良好的杂散特性改善微波电路的特性。我们成功地实现了E/M模拟所期望的具有较好杂散特性的谐振器的小型化，但损耗仍然大于预期。原因应该仅仅是印刷电路板上铜片的粗糙表面。因此，我们正在尝试在LTCC结构中制作它。2.宽耦合开环谐振器之间的相互作用非常强。我们试图利用这种结构来实现宽带带通滤波器。通过我们的共面结构和多级BPF，很容易实现带宽的调节和与外部电路的匹配。我们提出了一个统一的程序来计算谐振器的谐振频率、外加Q、空载Q和耦合系数。所需要的数据是谐振器场强的时间变化。它与传统的基于S参数频率特性的频域方法具有对偶性。我们提出了一种区分谐振器耦合系数电磁贡献的新公式。许多重要的例子对耦合机理有了很好的理解。

1.Multilayered interdigital resonators based on the concept of artificial dielectrics will improve the microwave circuit characteristics by miniaturization, low loss and good spurious property. We have succeeded to miniaturize the resonator with improved spurious property as was expected by E/M simulation, but the loss is still bigger than the expectation. The reason should simply be the rough surface of the Cu sheets on the PCB. Thus, we are trying to fabricate it in the LTCC structure.2.Broad side coupled open ring resonators interact quite strongly each other. We try to realize a broad-band BPF utilizing this structure. Adjustment of the band width and matching to the external circuit are easily attained by our coplanar configuration together with the multi-stage BPFs. The LTCC implementation will be tried, too.3.We have proposed a unified procedure to calculate the resonant frequency, external Q, unloaded Q and coupling coefficient of resonators in the time domain. The necessary data are the time variation of the resonator field intensity. It is dual to the conventional frequency domain methods (FDM) which are based on the frequency characteristics of S parameters. The present method gives Q values easily that the FDMs sometimes find difficulty in calculating.4.We have proposed a new expression for discriminating the magnetic and electric contribution for the coupling coefficient of resonators. Many important examples gave a good understanding of the coupling mechanism.