| With the more and more intensive division of spectrum resources,people put forward higher and higher requirements on the transmission quality and transmission rate of data information in communication system.Nowadays mobile communication technology has developed to the fifth generation(5G).The filter as the core component of the RF front-end module of mobile communication,its performance determines the quality of data transmission in the communication system.Therefore,in order to meet the demands of the new age of mobile communication,the research of high-performance filter has important practical significance.The main content of this paper is as follows:1.A novel EBG bandpass filter based on low temperature co-fired ceramic(LTCC)technology is proposed.In this study,a novel energy coupling structure is applied to EBG structure to improve the external coupling capability of the device and reduce the insertion loss.Moreover,a high-quality factor(Q)capacitor based on LTCC process is introduced,which solves the problem that the traditional small-size EBG filter is difficult to achieve a low operating frequency.In addition to the characteristics of low loss and high operating frequency,the filter can also select the operating frequency by adjusting the capacitance of the built-in capacitor.Finally,the fabricated filters can work in different frequency bands,and the lowest measured loss is 1.91 d B.2.A reconfigurable EBG filter consisting of a carrier and an optional external capacitor is proposed.The carrier part is realized by printed circuit board(PCB)technology and the capacitor part is based on thin film integrated passive device(IPD)technology.The two are combined by using chip size package(CSP)technology.In addition,a rectangular slot energy coupling structure is applied to the carrier PCB,which enhances the internal coupling capacity of the filter and further improves the filter’s bandwidth.Especially,a high density IPD capacitor has been applied to replace the LTCC capacitor in the previous study,which results in the shrinkage of filter’s size(1.6 mm×1.35 mm).Moreover,the filter can operate in the 6.8 GHz to 13.8 GHz range by simply replacing external capacitors with different capacitance,which shows good device reusability advantages.Finally,the filter is processed and tested,and the experimental results are in agreement with the theory.3.A novel high-performance IPD bandpass filter for N77 band is proposed.In this filter,a three-dimensional high Q EBG inductor is used to replace the traditional plane IPD inductor,which improves the overall quality factor of the filter and reduces the in-band loss.The EBG inductor which applied to the resonant circuit is processed by PCB technology,while other circuit structures are integrated on the high resistance silicon substrate,and mechanical and electrical connections between the PCB carrier and the high resistance silicon chip are realized by flip chip ball grid array(FBGA)technology.The overall size of the N77 band filter(excluding the external pin)is 2.2 mm×3.0 mm,the 1d B bandwidth is 918 MHz,and the measured insertion loss with the evaluate board(EVB)is 2.58 d B.In addition,aluminum is used as the metal material in the chip part,which reduce the processing cost of the filter.Finally,a high performance IPD filter is realized in a lowcost way. |
