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IMPATT DIODEANDTRAPATT DIODEIMPATT DIODE IMPATT Stands Ior !act ionization valanche %ransit-%imen [uncLlon dlode ls revereblasedn [uncLlon dlode ls revereblasedAvalanche mulLlpllcaLlon of elecLrons and holes occurAvalanche mulLlpllcaLlon of elecLrons and holes occur1hls exhlblLs neaaLlve reslsLance characLerlsLlcs ln mlcrowave frequencv ranae1hls exhlblLs neaaLlve reslsLance characLerlsLlcs ln mlcrowave frequencv ranaeneaaLlve reslsLance ls based upon avalanche mulLlpllcaLlon and LranslLLlme effecL of carrlersneaaLlve reslsLance ls based upon avalanche mulLlpllcaLlon and LranslLLlme effecL of carrlersuevlce based on Lhls prlnclpal ls called Lhe lMA11 ulCuLuevlce based on Lhls prlnclpal ls called Lhe lMA11 ulCuLONSTRUTION OF IMPATT DIODE:JhereEQUIVALENT IRUIT FOR IMPATT DIODE:JhereOPERATION OF IMPATT DIODE:Voltage and :rrent Vs Time:IMPATT is designed Ior high power applications whereas, a diode b:rns (heat-:p) at high power.IMPATT is operated at reverse bias whereas a diode is normally operated at Iorward bias beca:se at reverse bias there is high voltage drop.OMPARISION . Operate at Ireq:encies between abo:t 3 and GHz or more.2. High power capability.ADVANTAGES OF IMPATT DIODE:DISADVANTAGES OF IMPATT DIODE :. Maior drawback oI :sing IMPATT diodes is the high level oI phase noise they generate.2. The noise Iig:re Ior IMPATT is 3dB .3. T:ning range is not as good as G:nn diodes.APPLIATION OF IMPATT DIODE:. MIROWAVE GENERATOR 2. MODULATED OUTPUT OSILLATOR3. REEIVER LOAL OSILLATOR4. PARAMETRI AMPLIFIER (par amps) 5. INTRUSION ALARM NETWORK6. FM TELEOMMMUNIATION TRANSMITTERS7. W DOPPLER RADAR TRANSMITTER.IMPATT DIODE OSILLATOR:WVery high Ireq:ency stabilityWHigh o:tp:t powerWLow phase noiseWFine spectr:mWPrecision Ireq:ency adi:stmentWWeak temperat:re dependenceWompact, low costTRAPATT DIODETRApped-Plasma Avalanche Trigged Transit Diode onstr:ction oI TRAPATT Diode: It is derived Irom IMPATT Diode. Silicon or Galli:m Arsenide is :sed Ior Iabricating TRAPATT Diode. TRAPATT Diode can be constr:cted either by p -n-n or n-p-p.OPERATION OF TRAPATT DIODE:A sq:are p:lse is :sed to excite TRAPATT diode.TRAPATT DIODE WAVEFORM: AB harging oI i:nction capacitanceB Electron and hole plasma Iormation by depressed IieldDE Plasma extraction EF Resid:al extraction FG harging oI diode GA onstant voltage aIter I:ll charging ANALYSIS OF TRAPATT DIODE: . The c:rrent density is given by,Where,2. Electric Iield is given by,Jhere3. Avalanche zone velocity is given by,SALIENT FEATURES OF TRPATT DIODE . It is a high eIIiciency diode oscillator .2. Its oscillations depend on delay in c:rrent ca:sed by avalanche process.3. The diode diameter is abo:t 5 mm Ior W operations and is abo:t 75 mm at lower Ireq:ency Ior high peak power application.4. It can be operated over a range oI 4MHz to 2GHz.5. Its has an eIIiciency oI 2 - 4.ADVANTAGES OF TRAPATT DIODE:. Its eIIiciency is relatively high.2. It can be :sed over a Ireq:ency range oI a Iew h:ndred MHz to several GHz.DISAVANTAGE OF TRAPATT DIODE:. It has high noise Iig:re.2. Its :se at :pper microwave Ireq:encies is limited .3. It generate strong harmonics d:e to the short d:ration oI c:rrent p:lse.APPLIATION OF TRAPATT DIODE :W in p:lse radar as local oscillator.W in radio altimeter.W air borne and marine radars.W in microwave beacons and landing system.W in low power Doppler radars.It is :sed inAPPLIATION OF MIROWAVE ENGINEERING IN BIOMEDIAL INSTRUMENTSBIOMEDIAL INSTRUMENTS The Signal !74.088ing and n897:20n9a9i4n S0.9i4n (S!S) provides electrical, electronic, electro-optical, and comp:ter engineering s:pport to clinical and biomedical research proiects involving advanced real-time signal transd:ction, signal processing, and control.FIG: A JARVIK-7 artiIicial heart, an example oI a biomedical engineering. APPLIATION IN STERILIZING MEDIAL EQUIPMENTS W S907iliza9i4n (or 8907ili8a9i4n) is a term reIerring to any process that eliminates (removes) or kills all Iorms oI liIe, incl:ding transmissible agents (s:ch as I:ngi, bacteria, vir:ses, spore Iorms, etc.) present on a s:rIace, contained in a Il:id, in medication, or in a compo:nd s:ch as biological c:lt:re media.W Sterilization can be achieved by applying the proper combinations oI heat, chemicals, irradiation, high press:re, and Iiltration.FIG: Sterilizing s:rgical instr:mentsW Low-cost technology to kill harmI:l bacteria has been developed at Glyndwr University in Wrexham.W Researchers Io:nd that by attaching a vac::m vessel to a microwave oven, atomic oxygen and ozone - both aggressive gases - can be generated.W The modiIied microwave :sed by the team cost less than 2,, compared to 7, Ior conventional systems.W The new method, developed by a team led by senior research scientist Dr Andy Wright, provides a chemical-Iree sol:tion to killing harmI:l bacteria on medical tools :sed in GP, dentist and veterinary s:rgeries.HOW MIROWAVES ARE USED FOR STERILIZING PROESS? 2. APPLIATION IN HISTOPATHOLOGYW ReIers to the microscopic examination oI tiss:e in order to st:dy the maniIestations oI disease. W SpeciIically, in clinical medicine, histopathology reIers to the examination oI a biopsy or s:rgical specimen by a pathologist, aIter the specimen has been processed and histological sections have been placed onto glass slides.FIG: Micrograph showing contraction band necrosis, a histopathologic Iinding oI myocardial inIarction (heart attack)HOW MIROWAVES ARE USED IN HISTOPATHALOGY ?W Microwave accelerated proced:res are :seI:l at every step oI sample preparation Ior microscopy by speeding :p reaction process and saving time.W Even more important , microwave proced:res improves the retention oI sol:ble Antigen imm:no reactivity better than conventional methods.W In short, microwave accelerated techniq:es can be :sed to improve the eIIiciency oI variety oI histopathology laboratory proced:res, s:ch as Iixation, decalciIication , processing oI specimens Ior paraIIin wax or resin embedding and staining.W Two types oI microwave devices are being :sed in histopathology laboratory setting :. Microwave instr:ments speciIically designed and certiIied as medical devices 2. ommercial grade microwave :nits modiIied Ior lab/clinicsW Laboratory microwave devices are designed with exha:st Ians and saIety Ieat:res to protect microwave devices.Presented By:GROUP 4Roll No:4 to 5