Research On Key Technology Of 3?45GHz Wideband Microwave Millimeter Wave Frequency Source

Various microwave systems and millimeter wave systems which are related to information transmission are inseparable from the existence of frequency synthesizer,the functions and performance that can be achieved by such systems depend on the performance of synthesizer and the quality of the selected technical solutions to a large extent.The development of modern radar,aerospace,mobile communications,guided weapons,electronic countermeasures and the rise of modern electronic warfare have made the frequency synthesizer need to meet the increasing requirements.It has become one of the main research trends to develop synthesizer with low phase noise,low spurs and wide frequency bands.Based on the important position of the frequency synthesizer in modern electronic systems and the wide application in military and civil fields,this thesis studies and designs a 3~45GHz wideband microwave millimeter wave frequency synthesizer.The circuit structure,realization principle and performance characteristics of several basic synthesis methods of modern frequency synthesis technology are explained,this provides the necessary theoretical support for the proposal of the synthesizer implementation plan.It is the point and difficulty to consider the unified improvement of multiple indicators in the system design.The advantages and disadvantages of various frequency synthesis methods are comprehensively considered in order to meet the requirements of a series of indicators for the output power,spur suppression and phase noise of the wideband frequency synthesizer developed in this thesis.The final design proposal is that the microwave wideband signal is generated utilizing a wideband phase-locked loop chip and then performed segmentation frequency multiplication,filtering and power amplification to realize the required frequency range.The hardware design adopts the idea of modularization,which is mainly divided into the microwave wideband frequency synthesizer in 3~11.25 GHz frequency band,the double frequency filtering and amplifying in 11.5~22.5GHz frequency band,the double frequency filtering and amplifying in 23~45GHz frequency band and the system power supply module.Finally,the output of each frequency band signal is realized by controlling the level of a series of switch chips to complete the channel switching.The preliminary work of each unit module includes the selection of key devices,the planning of the filtering scheme,the simulation design of the filter and the theoretical analysis and experimental verification of the indicators.The later work is mainly the design and processing of the circuit and cavity of each module and a series of commissioning and testing work.After each unit module completes the testing process,the modules are cascaded for system commissioning and testing.It can be seen from the final test results that the output signal with a frequency step of 500 MHz in the frequency range of 3~45GHz realized by this frequency synthesizer has better spur suppression than 35 dBc,the phase noise can reach-90dBc/Hz@10kHz in 3~45GHz,the output power can reach 17~23dBm in 3~45GHz.In general,most of the indicators achieved by this frequency synthesizer basically meet the expected requirements and it has certain engineering application value.