LTE Filters Design Based On LTCC Technolog

With the increasing and development on wireless communication and millimeter wave, a high performance integrated system on package, which consists of surface mounted integrated circuits, embedded passives, and subsystems, has attracted tremendous attention in recent years. The RF/Microwave devices need the character of high efficiency, high reliability, low cost and normal operation. The technology of Low Temperature Co-fired Ceramics process can satisfy the requirements of miniaturization, lower cost and higher frequency applications. LTCC has become the trend of the development of packaging technology and has been widely introduced by industry.LTCC technology is that the substrate can match well with silver paste electrode conductor overlying together, and achieves common matching sintered under temperature of less than 900 ℃. Passive components can be embedded in the inside of the ceramic substrate, and at the same time active components can also be mounted the up and down surface of substrate. It increases the flexibility in design and production, truly achieving the three-dimensional structure, so the LTCC technology has now become the research center and the mainstream technologies of passive circuit integration technology, is one of the key core technology of field development of radio frequency(RF) and microwave(MW).This essay connected the material characteristics, modeling design, and the fabrication process together. The research carried from the LTCC material to devices design and to production technology. Firstly, the LTCC new materials were researched, and the two kinds of materials,(Ni0.2Cu0.2Zn0.6)1.02(Fe2O3)0.98-1wt% BiVO4 which is a major material formula as production power inductor, and 0.9Ca(Zn1/3Nb2/3)O3-0.1Ba(Zn1/3Nb2/3)O3-10%B2O3-5%LiF ceramics which is the main material of LTE filters. The matching characters of the two materials were also explored, the result showed that the two material can form a monolithic structure without adverse phenomenon, like bubbles, cracks, warps. Secondly, the large current power laminated inductors were designed and developed with a 0.9Ca(Zn1/3Nb2/3) O3-0.1Ba(Zn1/3Nb2/3)O3-10%B2O3-5%LiF nonmagnetic layer and a substrate material(Ni0.2Cu0.2Zn0.6)1.02(Fe2O3)0.98-1wt% BiVO4. The effects on the DC characteristics of the inductor with nonmagnetic layers were studied. And found that the thickness, number, arrangement of non-magnetic air gaps made inductors possess different DC characteristics and inductance value. Power inductors with nonmagnetic layers were fabricated by LTCC process, and their characteristics were evaluated. Finally, LTE bandpass filters were researched and fabricated by LTCC technology.π type band-pass filter circuit with transmission zeros structure was adopted to design the filter. And ultimately the LTE filters based on LTCC technology were measured, the center frequency is at 2.6 GHz, return loss is 1.2 dB and insertion loss is 24.2 dB at center frequency, the insertion loss of the two transmission zeros were 50.6 dB and 62.5 dB 2.09 GHz and 3.03 GHz out of the band frequency respectively. LTE filters have the good restraint performance outside the band, the final size of LTE filter was 2.0 mm *1.2 mm * 0.8 mm.