Circuit of GaAsMMIC control of 1 foreword because bulk small, weight rate of light, switch is rapid, fight radiation, dependability tall, wait for distinct advantage to win wide application in a lot of electron systems without power comsumption almost. Well-known, the system waits in contemporary and advanced mobile (if the space divides market intelligence antenna and photograph to control a system) in, all need to undertake extent and phasic adjustment, average system all asks phasic when adjusting, extent change Yue Xiaoyue is good. And when extent is adjusted, phasic change Yue Xiaoyue is good. The GaAsMMIC that DC-50GHz carries to exceed a broadband in article presses attenuator of attune accusing report besides the degree of linearity that has limits of big dynamic attenuation, admirable attenuation to change along with control voltage, exceedingly good input / output standing wave and muti_function outside waiting for a characteristic, low insertion the markeddest characteristic that phase shift is this kind of chip. Accordingly, this kind of circuit can use as: A) low insert phase shift condition to fall, regard DC 50GHzMMIC as alterable attenuator, comprise automatic loss to control package; B) be in multiple in the vector modulator of frequency Cheng, in introduce low extent modulation and extent are finished to adjust a function when inserting phase shift; C) of DC-50GHz high-powered draw type (or say to match model) short-hilted broadsword sheet casts switch; D) multiple the pulse extent modulator of frequency Cheng; E) the AGC that as broadband as composition of broadband amplifier cascade belt, big trends, attenuation follows control voltage tall linear to change (automatic gain control) amplifier. 2 designs this kind of sheet piece press the design that accuses alterable attenuator and implementation, total consideration is as follows: -- ask according to electric function index, the circuit develop with right choice attacks the switch MESMET with structure and reasonable design; -- the proportion of parameter of equivalent circuit model that wins MESFET of the switch below DC-50GHz frequency limits shrinks put equation; -- use series connection and shunt-wound switch MESFET the laden design method such as two control end, simplify circuit and reduce power comsumption. Graph graph of 1 report principle pursues when 2 chip photograph works as a result of this kind of circuit, controlling voltage is a group of complementary voltage, control series connection and shunt-wound switch MESFET respectively. The load that the two control in electric tone process carry must identical, when pressing key accusing report otherwise, standing wave character is apparently exasperate. The load that normally circuit of design dc parameter balances two control to carry makes his identical, the improvement in achieving electric adjusting control to make is stationed in the purpose of wave character. The make choice of when the article used a design the method with two laden and same control, achieve the goal of character of the standing wave in improving electric adjusting control to make end. The process is as follows: -- the microwave that uses maturity is odd a circuit design software (like AgilentEesof software) the emulation that undertakes circuit and optimize; -- undertake according to optimized result domain is designed; -- undertake 2 times emulate and be optimizinged according to the domain of the design, be revised and decide domain; -- the craft way with choice and logical design; -- craft flows piece, microwave is in a test. Circuit principle is shown 1 times like the graph, use match model the develop of broadband switch circuit of SPST attacks, switch arm two end establish ties respectively the spur track that draws resistor and switch MESFET parallel connection and many with advocate the switch MESFET composition of transmission paralell connection, low chromatic dispersion, broadband tape used in circuit in all transmission line of face wave guide leads bandwidth with spreading frequency. The design is low the fundamental that inserts phase shift function basically is to use phasic and mutual quits principle. Namely concept of its circuit physics is: The phasic lead that the phasic lag that inductance of series connection spur track introduces and capacitive reactance of shunt-wound spur track introduce is mutual and quits. Circuit sets the index of main report function of timing consideration to be: -- the frequency limits of DC 50GHz; -- try to obtain the attenuation inside the smallest attenuation and frequency band to rise and fall; -- the low input when the smallest attenuation / output standing wave; -- the evenness of the attenuation inside the biggest attenuation and frequency band is spent; -- the low input when the biggest attenuation / output standing wave; -- attenuation of low phase shift, as far as possible little attenuation phase shift is compared. Circuit design uses AgilentEesof software, to acquire optimal report property, different MESFET should choose different optimal grid width, put a technology because of model parameter scale was being used to shrink in this design. Extraction of circuit model parameter uses HPIC-CAP software and system of corresponding model parameter extraction. Because design frequency to be as high as 50GHz, still used circuit model parameter to frequency expands and plan to combine a technology consequently in order to obtain the design parameter of model of circuit of DC-50GHz switch MESFET. The 3 chip that make use line of craft of wafer of infuse of ion of institute of Nanjing electronic parts to make, use ionic infuse craft to have taller n and long-term job stability. Craft includes Au/Ge/Ni ohm to contact metallization: 0. Bar of 5 μ M grows Ti/Pt/Au bar of base of power of Xiao Te radical; N ＋ , N - infuse; Ionic infuse resistor; Metallic film resistor; SiO2 passivation film; Microstrip line; Air bridge; Via ground connection; Rear metallization and eletroplate etc. Craft n is as high as 80 ％ above, the it is better to be provided with the electric function between wafer consistency between chip. Chip dimension is 2.
33mm × 0.
68mm × 0.
1mm. Chip photograph is shown 2 times like the graph. Signal is inputted / output end all is in all interface of face wave guide, use via ground connection and technology of multiple chip passivation, reliability is high. Control end all relies on chip a side, facilitating installation is used. The microwave that test of function of 4 performance report uses analyzer of HP8510C vector network and composition of stage of CascadeMicrotech microwave bougie is in a test system. Performance data is like all sorts of report of the test the smallest attenuation; The input when the smallest attenuation / output standing wave; The biggest attenuation; The input when the biggest attenuation / output standing wave; The phase shift of the smallest attenuation and the biggest attenuation is poor. It is 0V when V1, when V2 places voltage VP for the FET of negative pole sex, condition of corresponding the smallest attenuation. It is VP when V1, when V2 is 0V, condition of corresponding the biggest attenuation. Reduce VP gradually from 0V when V1, v2 increases 0V gradually from VP synchronism when, attenuation arrives from the least change the biggest, vice versa. Chip passed tall, low temperature to store, tall, low temperature is pounded, tall, low temperature works, bond, cut the experiment such as the life of 1000 hours of works that is 125 ℃ with working environment temperature. 5 conclusion development is successful low phase shift, muti_function high-powered MMIC of DC 50GHz is pressed accuse alterable attenuator, have good electric performance, taller craft n and high reliability, achieved design requirement, it is certain to have practical. CNC Milling
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