With the development of communication technology, handheld radio tabilao mihodina matetika ny teknolojia dia be mpampiasa kokoa, toy ny: pager tsy misy tariby, telefaona finday, PDA tsy misy tariby, sns., ny fahombiazan’ny tariby matetika amin’ny radio dia misy fiantraikany mivantana amin’ny kalitaon’ny vokatra iray manontolo. Ny iray amin’ireo mampiavaka azy indrindra amin’ny vokatra entin-tanana dia ny miniaturisation, ary ny miniaturisation dia midika fa ny hakitroky ny singa dia avo dia avo, izay mahatonga ireo singa (ao anatin’izany ny SMD, SMC, chip tsy mitera-bokatra sns …) mifanelingelina. Raha tsy tantana araka ny tokony ho izy ny famantarana ny fanelingelenana elektromagnetika dia mety tsy mandeha tsara ny rafitra boribory iray manontolo. Noho izany, ny fomba fisorohana sy fanakanana ny fanelingelenana elektromagnetika sy fanatsarana ny fifandanjana elektromagnetika dia nanjary lohahevitra iray tena lehibe tamin’ny famolavolana RF circuit PCB. Ilay faribolana iray ihany, firafitra famolavolana PCB samy hafa, tsy mitovy mihitsy ny mari-pandrefesany. Ity taratasy ity dia miresaka momba ny fomba hampitomboana ny fahombiazan’ny fizaran-tany hahatratrarana ny fepetra takian’ny elektromagnetika rehefa mampiasa rindrambaiko Protel99 SE handrafetana RF circuit PCB an’ny vokatra palma.

1. Fifidianana lovia

The substrate of printed circuit board includes organic and inorganic categories. Ny fananana manan-danja indrindra amin’ny substrate dia ny diélectric tsy miova ε R, ny fihanaky ny fiparitahana (na ny fatiantoka diélectrique) Tan δ, ny coefficient CET mivelatra amin’ny hafanana ary ny fidiran’ny hamandoana. ε R affects circuit impedance and signal transmission rate. Ho an’ny boriborintany matetika, ny fandeferana amin’ny alàlan’ny alàlan’ny alàlan’ny alàlan’ny alàlan’ny alàlan’ny alàlan’ny alàlan’ny alàlan’ny alàlan’ny alàlan’ny alàlan’ny alàlan’ny fandeferana dia tokony ho voafantina.

2. PCB design process

Because Protel99 SE software is different from Protel 98 and other software, the process of PCB design by Protel99 SE software is briefly discussed.

① Because Protel99 SE adopts the PROJECT database mode management, which is implicit in Windows 99, so we should first set up a database file to manage the circuit schematic diagram and PCB layout designed.

② Design of schematic diagram. Mba hahatsapana ny fifandraisana amin’ny tamba-jotra, ny singa rehetra ampiasaina dia tsy maintsy misy ao amin’ny tranomboky singa alohan’ny famolavolana fitsipika; raha tsy izany dia tokony hatao amin’ny SCHLIB ireo singa ilaina takiana ary tehirizina ao anaty rakitra fisie. Avy eo, miantso fotsiny ireo singa ilaina ao amin’ny tranomboky mpiorina ianao ary mampifandray azy ireo arakaraka ny kisary natao ho an’ny faritra.

③ After the schematic design is completed, a network table can be formed for use in PCB design.

④PCB design. A. Famaritana endrika sy habe CB. The shape and size of PCB are determined according to the position of PCB in the product, the size and shape of the space and the cooperation with other parts. Draw the shape of the PCB using the PLACE TRACK command on MECHANICAL LAYER. B. Manaova lavaka fametrahana, maso ary teboka ao amin’ny PCB arakaraka ny fepetra takian’ny SMT. C. Production of components. If you need to use some special components that do not exist in the component library, you need to make components before layout. Ny fizotry ny fananganana singa ao amin’ny Protel99 SE dia tsotra ihany. Safidio ny baiko “MAKE LIBRARY” ao amin’ny menio “DESIGN” hiditra amin’ny varavarankely fanaovana KOMPONENTY, ary avy eo safidio ny baiko “KOMPONENT vaovao” ao amin’ny menio “TOOL” mankany DESIGN. Amin’izao fotoana izao, manaova sary ny PAD mifanentana amin’ny toerana iray ary ovao amin’ny PAD takiana (ao anatin’izany ny endrika, habe, savaivony anatiny ary ny zoro ny PAD, sns. TOP LAYER miaraka amin’ny baikon’ny PLACE PAD sns sns araka ny endrika sy ny haben’ny singa tena izy. Then use the PLACE TRACK command to draw the maximum appearance of the component in the TOP OVERLAYER, select a component name and store it in the component library. D. Rehefa vita ny singa dia alefa ny layout sy ny tariby. Ireto fizarana roa ireto dia horesahina amin’ny antsipiriany etsy ambany. E. Check after the above procedure is complete. Amin’ny lafiny iray, ity dia misy ny fanaraha-maso ny fitsipiky ny fizaran-tany, etsy ankilany, ilaina ny manamarina ny fampifangaroana sy ny fivorian’ny tsirairay. The circuit principle can be checked manually or automatically by network (the network formed by schematic diagram can be compared with the network formed by PCB). F. Rehefa avy nanamarina dia arisaho ary avoaho ny rakitra. Ao amin’ny Protel99 SE, dia tsy maintsy mihazakazaka ny baiko EXPORT ianao amin’ny safidin’ny FILE hitahiry ny FILE amin’ny làlana voatondro sy ny FILE (ny baiko IMPORT dia ny FANAPORANA FILE mankany Protel99 SE). Fanamarihana: ao amin’ny safidy “FILE” Protel99 SE “SAVE COPY AS…” Aorian’ny fampiharana ny baiko dia tsy hita ao amin’ny Windows 98 ny anaran’ny fisafidianana, noho izany dia tsy hita ao amin’ny Resource Manager ny fisie. Tsy mitovy amin’ny “SAVE AS…” ao amin’ny Protel 98 ity. Tsy mitovy ny asany.

3. Components layout

Satria ny SMT amin’ny ankapobeny dia mampiasa fantsom-pandrefesana lafaoro infrared mba hampiorina ireo singa, ny fiorenan’ny singa dia misy fiatraikany amin’ny kalitaon’ny tonon-taolana, ary avy eo misy fiantraikany amin’ny vokatry ny vokatra. For PCB design of rf circuit, electromagnetic compatibility requires that each circuit module does not generate electromagnetic radiation as far as possible, and has a certain ability to resist electromagnetic interference. Therefore, the layout of components also directly affects the interference and anti-interference ability of the circuit itself, which is also directly related to the performance of the designed circuit. Therefore, in the design of RF circuit PCB, in addition to the layout of ordinary PCB design, we should also consider how to reduce the interference between various parts of the RF circuit, how to reduce the interference of the circuit itself to other circuits and the anti-interference ability of the circuit itself. Raha ny zava-niainana, ny vokatry ny fizaran-tany RF dia tsy miankina amin’ny indéks’ny RF circuit board ihany fa miankina amin’ny fifandraisana amin’ny birao fanodinana CPU amin’ny lafiny lehibe. Noho izany, amin’ny famolavolana PCB dia manan-danja manokana ny fisehon-javatra mirindra.

General layout principle: components should be arranged in the same direction as far as possible, and the bad welding phenomenon can be reduced or even avoided by selecting the direction of PCB entering the tin melt system; Araka ny traikefa, ny elanelana misy eo anelanelan’ny singa dia tokony ho 0.5mm farafaharatsiny mba hamenoana ny fepetra takiana amin’ireo singa-mandrendrika firaka. Raha mamela ny habaky ny birao PCB, ny habaka misy eo anelanelan’ny singa dia tokony ho araka izay azo atao. Ho an’ny tontonana roa sosona, ny lafiny iray dia tokony ho natao ho an’ny singa SMD sy SMC, ary ny lafiny iray kosa dia singa tsy mitovy.

Fanamarihana amin’ny fisehosehoana:

* First determine the position of interface components on the PCB with other PCB boards or systems, and pay attention to the coordination of interface components (such as the orientation of components, etc.).

* Noho ny habetsaky ny vokatra an-tànana, ny singa dia voalamina amin’ny fomba voafintina, ka ho an’ny singa lehibe kokoa dia tsy maintsy omena laharam-pahamehana ny famaritana ny toerana sahaza azy, ary diniho ny olan’ny fandrindrana.

* Rafitra fizahana fandinihana tsara, ny fanodinana fantsom-pifandraisana (toy ny fantsom-pamokarana avo lenta, ny fampifangaroana ny fizaran-tany sy ny fikajiana demodulation sns), araka izay azo atao mba hampisarahana ny famantarana mavesatra ankehitriny sy ny fambara malemy ankehitriny, ny fikajiana signal digital nomerika ary ny signal analog. boribory, fenoy ny fiasa mitovy amin’ny boriborintany dia tokony hapetraka amin’ny sehatra iray, amin’izay hampihena ny faritra misy fantsona famantarana; Ny tamba-jotra sivana isaky ny faritra ao amin’ilay faribolana dia tsy maintsy ampifandraisina eo akaiky eo, mba tsy hihena ihany ny taratra, fa azo ahena ihany koa ny mety hisian’ny fidirana an-tsehatra, arakaraka ny fahaizan’ny anti-interferensi an’ny faritra.

* Boriborintany boribory sela arakaraky ny fahatsapany ny fitoviana elektromagnetika ampiasaina. The components of the circuit that are vulnerable to interference should also avoid interference sources (such as interference from the CPU on the data processing board).

4. Tariby

After the components are laid out, wiring can begin. The basic principle of wiring is: under the condition of assembly density, low-density wiring design should be selected as far as possible, and signal wiring should be as thick and thin as possible, which is conducive to impedance matching.

Ho an’ny fizaran-tany RF, ny endrika tsy mitombina amin’ny fitarihan’ny tsipika famantarana, ny sakany ary ny elanelan’ny tsipika dia mety hahatonga ny fitsabahana eo amin’ny tsipika fampitana signal; Ankoatr’izay, ny rafitra famatsiana herinaratra dia misy ihany koa ny fanelingelenana amin’ny tabataba, noho izany amin’ny famolavolana RF circuit PCB dia tsy maintsy heverina ho feno, tariby mirindra.

Rehefa tariby, ny tariby rehetra dia tokony ho lavitra ny sisintanin’ny tabilao THE PCB (eo ho eo amin’ny 2mm), mba tsy hiteraka na hanana ny loza mitatao amin’ny fahatapahana tariby mandritra ny famokarana birao PCB. Ny tsipika herinaratra dia tokony ho araka izay azo atao mba hampihenana ny fanoherana ny tadivavarana. Mandritra izany fotoana izany, ny làlan’ny tsipika herinaratra sy ny tsipika ifotony dia tokony hifanaraka amin’ny làlan’ny fampitana angon-drakitra hanatsarana ny fahaizan’ny fanoherana. Ny tsipika famantarana dia tokony ho fohy araka izay azo atao ary ny isan’ny lavaka dia tokony hahena araka izay tratra. Ny fohy kokoa ny fifandraisana misy eo amin’ny singa, ny tsara kokoa, mba hampihenana ny fizarana ny masontsivana sy ny electromagnetic interferensi eo amin’izy samy izy; For incompatible signal lines should be far away from each other, and try to avoid parallel lines, and in the positive two sides of the application of mutual vertical signal lines; Wiring in need of corner address should be 135° Angle as appropriate, avoid turning right angles.

Ny tsipika mifandray mivantana amin’ny pad dia tsy tokony ho malalaka be, ary ny tsipika dia tokony ho lavitra ireo singa tapaka raha lavitra araka izay azo atao mba hisorohana ny lalan-kely; Holes should not be drawn on components, and should be far away from disconnected components as far as possible to avoid virtual welding, continuous welding, short circuit and other phenomena in production.

In PCB design of rf circuit, the correct wiring of power line and ground wire is particularly important, and reasonable design is the most important means to overcome electromagnetic interference. Quite a lot of interference sources on PCB are generated by power supply and ground wire, among which ground wire causes the most noise interference.

Ny antony lehibe mahatonga ny tariby ambanin’ny tany mora mahatonga ny fahatapahana elektromagnetika dia ny fisakanana ny tariby amin’ny tany. When a current flows through the ground, a voltage will be generated on the ground, resulting in the ground loop current, forming the loop interference of the ground. When multiple circuits share a single piece of ground wire, common impedance coupling occurs, resulting in what is known as ground noise. Therefore, when wiring the ground wire of the RF circuit PCB, do:

* Voalohany indrindra, ny fizaran-tany dia mizara ho sakana, ny RF circuit dia azo zaraina amin’ny ankapobeny ho fanamafisam-peo avo, fampifangaroana, fametahana demodulation, hovitrovitra eo an-toerana sy ny faritra hafa, mba hanomezana teboka iraisana mety iraisana isaky ny fizaran-tany circuit faritra, ka ny famantarana dia azo ampitaina eo anelanelan’ny maodelin’ny fizaran-tany samihafa. Avy eo dia fintinina amin’ny teboka ampifandraisin’ny RF circuit PCB amin’ny tany, izany hoe fintino amin’ny tany lehibe. Satria misy teboka tokana tokana, dia tsy misy fitambarana impedance iraisana ary noho izany dia tsy misy olana eo amin’ny samy hafa.

* Faritra dizitaly sy faritra anariôma araka izay azo atao ny fitokana-monina tariby ary ny tany nomerika sy ny tany analog mba hampisaraka, farany mifandray amin’ny tany famatsiana herinaratra.

* Ny tariby mihodina amin’ny faritra tsirairay amin’ny boriboritany dia tokony hanisy fiheverana ihany koa ny fotokevitra tokana miorim-paka, hampihena ny faritry ny fantsom-pifandraisana ary ny adiresin’ny faritra misy ny sivana eo akaiky eo.

* Raha mamela ny habaka dia tsara kokoa ny manavaka ny modely tsirairay amin’ny tariby mandeha amin’ny tany mba hisorohana ny fiarahan’ny famantarana eo amin’ny samy izy.

5. famaranana

Ny lakilen’ny famolavolana RF PCB dia mitoetra amin’ny fomba fampihenana ny fahaizan’ny taratra sy ny fanatsarana ny fahaiza-manao fanoherana. Layout sy tariby mirindra no antoky ny DESIGNING RF PCB. Ny fomba voalaza ato amin’ity taratasy ity dia manampy amin’ny fanatsarana ny fahamendrehan’ny famolavolana RF circuit PCB, hamaha ny olan’ny fanelingelenana elektromagnetika, ary hahatratra ny tanjon’ny fifandanjana elektromagnetika.