Development Of Key Components Of Vector Network Analyzer 3mm Band Spread Spectrum Module

In recent years,with the in-depth development of the general trend of militarycivilian integration,the 3mm frequency band is at the commanding heights of various countries in military and defense fields such as millimeter wave radar,electronic countermeasures,precision guidance,and confidential communications.More and more attention has also been paid to civilian fields such as runway foreign body detection and automobile collision avoidance systems.The prerequisite to support the vigorous development of various fields is the development and application of 3mm frequency band devices.However,the 3mm frequency band vector network analyzer(VNA)is essential for the development and measurement of millimeter wave devices.Therefore,the development of key components of the VNA 3mm-band spread spectrum component,and the realization of the old model VNA to achieve spread spectrum at low cost,so that it has the ability to cover the 3mm wave measurement,has important engineering significance and great economic value.The main content of this article is as follows.First of all,according to the requirements of the subject,this paper proposes a singleport fixed local oscillator mixed intermediate frequency 3mm-band spread spectrum component program,determines the main technical indicators of the spread spectrum component,and analyzes the advantages and disadvantages of the program.According to the 3mm spread spectrum component plan,this paper has determined the concrete realization plan of 3 key components(up-conversion link,local oscillator frequency multiplication link,3mm high directivity directional coupler),and carried out the component link index allocation.In the up-conversion link,the IF signal(2-12GHz)is amplified by the IF amplifier and enters the mixer for up-conversion to the 3mm frequency band(90-100GHz),and then enters the RF amplifier to amplify the output after filtering.The link adopts two-stage amplification to avoid the risk of single-stage highgain self-excitation.The local oscillator frequency multiplier link uses a signal source to generate the 11 GHz point frequency signal,which is multiplied to 88 GHz by an active X8 multiplier and filtered to meet the power requirement(+7d Bm)of the LO input port of the 3mm mixer.Secondly,considering the flexibility of the circuit,this article adopts a modular approach to develop active and passive modules.Among them,the active modules are all developed based on the MMICs using a hybrid integrated circuit form,and the relevant indicators of each active module have been measured to meet the requirements of the subject indicators.For the key passive modules,the directional coupler in this paper adopts the waveguide porous directional coupler for the 3mm frequency band characteristics.The measured directivity can reach up to 35.6d B.Some indicators are better than the commercial 12615 A broadband high directivity directional coupler of the41 st Research Institute of China Electronics Technology Group.Based on the fin-line structure,two filters,90-100 GHz and 87.7-88.3GHz,were developed for up-conversion,local oscillator frequency multiplication link frequency selection,and harmonic suppression,and the actual measurements met the index requirements.Based on the waveguide-microstrip transition structure developed for the ridge fin line,the insertion loss(IL)is less than 0.75 d B and the return loss(RL)is better than 10 d B in the 85-100 GHz frequency band.In addition,the developed calibration kit based on the TRL calibration method has a good effect in the entire W frequency band,and the return loss after calibration is better than 40 d B.Finally,on the basis of the completion of the development of various passive active components,the overall link test of the key components of the 3mm spread spectrum assembly is carried out.Due to the lack of W-band power meters in the laboratory,a calibrated W-band detector is used to build a 3mm-band power test system with vector network analyzers,signal sources and other instruments.The actual measurement shows that the overall link is in the range of IF input power of-25?-20 d Bm,RF output is-0.82?6.3d Bm,and the overall link gain is greater than 24 d B.In summary,the development of key components of the VNA 3mm-band spread spectrum component has reached the expected design index.