Passive Device Design Based On LTCC Technology

Due to the gradual crowding low-frequency spectrum resources and accelerated deployment and commercialization of 5G,millimeter wave with rich spectrum resources has been widely concerned by researchers of various countries.Communication systems in millimeter wave-band put forward higher requirements for miniaturization of passive devices.Filters and antennas are the two categories in passive devices that develop rapidly and have a great impact on the performance of the whole communication system as important components in the front end of communication system.Benefiting to the advantages of high integration and low loss,the passive devices based on LTCC(Low Temperature Co-fired Ceramic)are favored by researchers in miniaturized technologies.With millimeter encapsulation technology,LTCC technology makes the passive devices develop toward the direction of miniaturization and high performance and prevents its performance from external factors as much as possible.In this paper,the passive devices based on LTCC technology are studied in millimeter wave band.The main research contents are as follows:1.In order to solve the problem of large size of traditional microstrip antenna array,a 22? multi-ayer slot antenna array with center frequency of128 GHz was designed by using LTCC technology.The multi-layer structure not only reduces the size,but also achieves better radiation performance.2.In view that the traditional microstrip structure and slot structure cause the gain of the array antenna reduced in large array antenna due to transmission loss,the cavity structure is introduced in the multi-layer medium to reduce the number of layers of electromagnetic wave transmission,reduce the losses and enhance the gain of antenna.41? cavity line array with center frequency 99 GHz and 42? cavity area array with center frequency 96 GHz were designed respectively for the cavity structure.The results of high gains of 12.8dB and 9.75 dB were obtained by simulation.3.In this paper,LTCC technology and substrate integrated waveguide(SIW)technology was combined to design a kind of band-pass filter with a center frequency of 98 GHz.In view of the poor out of band cut-off performance of the filter,a ridge structure with band-stop characteristics was loaded into the filter to introduce transmission zeros to enhance the out of band cut-off performance of the filter.Therefore,a band-pass filter with two transmission zeros is successfully realized.4.Based on the original 98 GHz band pass filter,a filter antenna with center frequency of 98 GHz was designed combining the filter with array antenna structure.Then a filter antenna with good performance was obtained by combining the filter and the antenna.