The Research And Application Of Balun And Filter Based On LTCC Technology

In RF circuits,some components determine the performance of the RF circuits,such as antennas,amplifiers,filters,power dividers and baluns,As important of the RF circuit,balun and the filter have a very large market demand in the military field and civilian areas.At present in the market,the balun and filter can not meet the current development requirements,so the research of device miniaturization,low cost,high integration for wireless communications is necessary.Used of new Technology to design and manufacture of stable performance,miniaturization,low cost of balun and filter.In the continuous development of technology,low-temperature co-fired ceramic(LTCC)technology show its unique advantages slowly.This paper has discussed the balun and filter based on LTCC technology,the main work is as follows:(1)The paper design a miniaturization Marchand Balun based on LTCC technology.Using the simulation and analysis of HFSS,the corresponding miniaturized balun objects were prepared.The length of the balun samples is 1.98mm,and the width is 1.23mm,The results were as follows:in the bandwidth range,the echo coefficients are between-13dB and-16dB,The amplitude difference required for the design is also shown and its value is less than 1 dB.The value of the phase difference can also be read from the result graph,its value is less than 10°.(2)A band-pass filter with no zero transmission and a band-pass filter with a zero transmission point are designed based on LTCC technology.These two filters are studied theoretically and did not make the two filters in real terms,which makes the theory upholstery for the design of miniaturized band-pass filter with two transmission zeros.Then the filter is processed into objects.The filter size is only for 2.0mm×1.2mm,the processing of a good sample was detected,the bandwidth is far greater than 100MHz,and it wider than other filters,bandpass insertion loss is less than 1.5dB,VSWR is less than 2.0.In this paper,the biggest feature of imporved Balun's products is the rational use of its internal space and set the coupling line spacing,so the size of Balun is 2.0mm×1.25mm×0.8mm.Currently on the market,the size of most balun size is relatively large,and the bandwidth is relatively small.Due to the reasonable use of capacitance and inductance model,the bandwidth of proposed Bandpass filter is bigger than standard bandwidth and the insertion loss is very low.In addition,With the meticulous arrangemen,the size of our product is very small,which is only 2.0mm × 1.2mm.