Research On Co-design Techonology Of X-Band Low Noise Amplifier And Band Pass Filter

In the function realization of various microwave radio frequency circuits,signal amplification and filtering are essential components.With the development of materials technology,advances in research technology,and the advancement of cutting-edge theory,today's new radars and wireless communication systems are increasingly challenging the design of electronic components such as amplifiers and filters:higher standards.performance metrics,smaller size,lighter weight and lower manufacturing costs.To this end,this paper proposes a method of co-design,which considers several components of the RF front-end as a whole,and achieves the goal of improving circuit performance and miniaturizing the circuit while reducing components and reducing the matching network between each unit circuit.The advantage of co-design is that by integrating the functions of various components,the multi-function of the circuit and the integration of the package are realized,the cost and integration difficulty of the RF system are reduced,and the device is rationally configured and comprehensively utilized to reduce power consumption and improve circuit performance.The main research contents of this thesis are as follows:Firstly,the theoretical basis of low noise amplifier(LNA)is introduced,and the main performance parameters that need to be paid attention to during the design of LNA are given.According to the design idea of LNA,the parameters such as noise figure,gain and standing wave ratio are started with.The simulation design was carried out by ADS software.The single-stage LNAand two-stage LNA working in the X-band were designed by microstrip matching method and made into physical objects.The test results show that in the working frequency band of 9.6GHz-10.5GHz,the single-stage LNA's noise figure is<0.7dB,power gain is>10dB,input and output standing wave ratio is less than 1.4,the two-stage LNA's noise figure is<1.7dB,power gain is>17dB,and input and output standing wave ratio is less than 1.5.Secondly,based on the theoretical research of microwave filter and substrate integrated waveguide(SIW)5 a miniaturized structure of SIW bandpass filter(BPF)with complementary split ring resonators(CSRR)is proposed.and its 3D model was modeled in HFSS.The relationship between the size parameters and the field strength distribution of the structure was analyzed by simulation to obtain the optimal transmission design.The test results show that the center frequency of the CSRR-SIW filter is 10.3GHz,the insertion loss is<1dB,and the port standing wave ratio is<1.3.Finally,a method for co-design of LNA and matching filter is proposed.By designing the input impedance of the filter as the conjugate of the LNA output impedance,the 50? impedance matching network between the traditional unit circuits is removed,so that the filter can simultaneously achieve impedance matching and filtering.The co-design of LNA-BPF circuit is processed and tested.The results show that compared with the traditional unit circuit cascaded amplification filter module,under the premise of realizing the function of each component,co-design reduces the circuit's size by 32%,increases the gain by 2dB,and reduces the noise figure by 0.1 dB.Performance optimization is achieved on the basis of circuit miniaturization,which is beneficial to reduce matching circuit loss,reduce cost,and improve integration.