Research And Design Of L Band Lowpass Filter For Multilayer Microstrip Line

With the continuous development of the communication technology,the resources of short wave and ultra short wave communication frequency are very scarce.In addition,the users need wider channel bandwidth to achieve high-speed data communication,so the communication equipment of L-band is developing rapidly.At present,the corresponding equipment has been installed in foreign countries,but at home it is still at the stage of demonstration.The frequency of domestic communication equipment is mainly used in the whole section of HF frequency band(1.6MHz~30MHz),and the following parts of UHF band(300MHz~3000MHz)are 1GHz.In addition,there are the L?S frequency band occupied by mobile communication and satellite communication and higher frequency spectrum resources.Once the spectrum resources of the L band are fully utilized,it is necessary to make rational planning,and the harmonics filter must be added in the equipment.This paper is aimed at the above problems,and carries on the research and design of a low pass filter for multi-layer microstrip line.The topic belongs to the communication equipment technology field of L communication band(1GHz~2GHz),and it is a small size that is realized by using microstrip line technology on multi-layer printing plate.The main contents of this thesis are as follows:1.The research background and important significance of this thesis are introduced,and the research situation and application of microstrip line filtering are briefly introduced.It also lists the main contribution and innovation of this paper in the field of academic and engineering application.2.Follow the simple to the difficult design train of thought,we did the discussion of the filter,the microstrip and the microstrip filter.The design method of the microstrip line filter and the design of l-band low pass microstrip line filter are also introduced.The filter is 1.42 GHz and 2GHz low pass filter,and the attenuation of passband is less than 1.5dB,and the attenuation of stopband is larger than 40 d B.3.The design and attention of the filter layout described in this paper are expounded from the aspect of engineering realization.According to the engineering application miniaturization requirements,we use the laminated structure to design the microstrip line filter,and according to the microstrip line filter characteristics and assembly requirements,the microstrip line filter is designed for patch packaging.This paper also introduces the points of attention when designing the pin.4.After the realization of the project,the module test and system test were carried out for the low pass filter of the multi-layer microstrip line L band,and the test results were analyzed and the improvement scheme was put forward.