The interconnect of tejede Circuit ọkọ eto pẹlu igbimọ-si-Circuit, isopọ laarin PCB ati isopọ laarin PCB ati awọn ẹrọ ita. In RF design, the electromagnetic characteristics at the interconnect point is one of the main problems faced by engineering design. This paper introduces various techniques of the above three types of interconnect design, including device installation methods, isolation of wiring and measures to reduce lead inductance.

Awọn ami wa ti a ṣe apẹrẹ awọn igbimọ Circuit ti a tẹ pẹlu igbohunsafẹfẹ jijẹ. As data rates continue to increase, the bandwidth required for data transmission also pushes the signal frequency ceiling to 1GHz or higher. This high frequency signal technology, although far beyond the millimeter wave technology (30GHz), does involve RF and low-end microwave technology.

Awọn ọna apẹrẹ imọ -ẹrọ RF gbọdọ ni anfani lati mu awọn ipa aaye itanna ti o lagbara ti o jẹ ipilẹṣẹ ni igbagbogbo ni awọn igbohunsafẹfẹ giga. Awọn aaye itanna wọnyi le ṣe awọn ifihan agbara lori awọn laini ifihan ti o wa nitosi tabi awọn laini PCB, nfa crosstalk ti a ko fẹ (kikọlu ati ariwo lapapọ) ati ipalara iṣẹ ṣiṣe eto. Backloss is mainly caused by impedance mismatch, which has the same effect on the signal as additive noise and interference.

High return loss has two negative effects: 1. The signal reflected back to the signal source will increase the noise of the system, making it more difficult for the receiver to distinguish noise from signal; 2. 2. Ifihan eyikeyi ti o farahan yoo ṣe ibajẹ didara ifihan naa ni pataki nitori apẹrẹ ti ifihan titẹ sii yipada.

Botilẹjẹpe awọn eto oni -nọmba jẹ ifarada ẹbi pupọ nitori wọn ṣe pẹlu awọn ami 1 ati 0 nikan, awọn harmonics ti ipilẹṣẹ nigbati pulusi ti nyara ni iyara to ga jẹ ki ifihan jẹ alailagbara ni awọn igbohunsafẹfẹ giga. Botilẹjẹpe atunse aṣiṣe siwaju le ṣe imukuro diẹ ninu awọn ipa odi, apakan ti bandiwidi eto ni a lo lati atagba data apọju, ti o yorisi ibajẹ iṣẹ. Ojutu ti o dara julọ ni lati ni awọn ipa RF ti o ṣe iranlọwọ kuku ju idinku lati iduroṣinṣin ifihan. A ṣe iṣeduro pe pipadanu ipadabọ lapapọ ni igbohunsafẹfẹ ti o ga julọ ti eto oni -nọmba kan (nigbagbogbo aaye data ti ko dara) jẹ -25dB, deede si VSWR ti 1.1.

Apẹrẹ PCB ni ero lati kere, yiyara ati din owo. Fun RFPCB, awọn ifihan agbara iyara nigbakan ṣe idinwo miniaturization ti awọn apẹrẹ PCB. Ni lọwọlọwọ, ọna akọkọ lati yanju iṣoro idapọmọra ni lati ṣe iṣakoso asopọ ilẹ, ṣiṣe aye laarin wiwa ati dinku inductance asiwaju. Ọna akọkọ lati dinku ipadabọ ipadabọ jẹ ibaamu ikọlu. Ọna yii pẹlu iṣakoso ti o munadoko ti awọn ohun elo idabobo ati ipinya ti awọn laini ifihan agbara ati awọn laini ilẹ, ni pataki laarin ipo ti laini ifihan ati ilẹ.

Nitori isopọpọ jẹ ọna asopọ ti ko lagbara julọ ninu pq Circuit, ni apẹrẹ RF, awọn ohun -ini itanna ti aaye isopọ jẹ iṣoro akọkọ ti nkọju si apẹrẹ imọ -ẹrọ, aaye asopọ kọọkan yẹ ki o ṣe iwadii ati awọn iṣoro to wa tẹlẹ yanju. Isopọ igbimọ Circuit pẹlu isọdọkan ọkọ-si-Circuit interconnection, isọdọkan PCB ati titẹ sii ifihan/isopọ iṣelọpọ laarin PCB ati awọn ẹrọ ita.

I. Isopọ laarin chiprún ati igbimọ PCB

Boya tabi kii ṣe ojutu yii n ṣiṣẹ, o han fun awọn olukopa pe imọ -ẹrọ apẹrẹ IC jẹ ṣiwaju iwaju ti imọ -ẹrọ apẹrẹ PCB fun awọn ohun elo hf.

Isopọ PCB

Awọn imuposi ati awọn ọna fun apẹrẹ PCB hf jẹ bi atẹle:

1. A gbọdọ lo igun 45 ° fun igun laini gbigbe lati dinku ipadabọ ipadabọ (Ọpọtọ. 1);

2 iye idabobo igbagbogbo ni ibamu si ipele ti iṣakoso adaṣe iṣẹ ṣiṣe giga ti o muna ti o muna ti o ga julọ. Ọna yii jẹ anfani fun iṣakoso ti o munadoko ti aaye itanna laarin awọn ohun elo idabobo ati wiwakọ ti o wa nitosi.

3. Awọn alaye apẹrẹ PCB fun etching to peye yẹ ki o ni ilọsiwaju. Gbiyanju lati ṣalaye asise iwọn laini lapapọ ti +/- 0.0007 inches, ṣiṣakoso abẹrẹ ati awọn apakan agbelebu ti awọn apẹrẹ wiwu ati sisọ awọn ipo gbigbe ẹgbẹ odi. Overall management of wiring (wire) geometry and coating surfaces is important to address skin effects related to microwave frequencies and to implement these specifications.

4. Ifọwọkan tẹ ni awọn idari ti n jade. Yago fun lilo irinše pẹlu nyorisi. Fun awọn agbegbe igbohunsafẹfẹ giga, o dara julọ lati lo awọn paati ti a fi sori ilẹ.

5. Fun ifihan nipasẹ awọn iho, yago fun lilo ilana PTH lori awo ti o ni imọlara, nitori ilana yii le fa inductance asiwaju ni iho nipasẹ. Lead inductance can affect layers 4 to 19 if a through-hole in a 20-ply board is used to connect layers 1 to 3.

6. Pese lọpọlọpọ ilẹ fẹlẹfẹlẹ. Moulded holes are used to connect these grounding layers to prevent 3d electromagnetic fields from affecting the circuit board.

7. Lati yan ti kii-electrolysis nickel plating tabi ilana imularada goolu, maṣe lo ọna fifẹ HASL. Ilẹ electroplated yii n pese ipa awọ ti o dara julọ fun awọn ṣiṣan igbohunsafẹfẹ giga (Nọmba 2). In addition, this highly weldable coating requires fewer leads, helping to reduce environmental pollution.

8. Solder resistance layer can prevent solder paste from flowing. Sibẹsibẹ, nitori ailojuwọn ti sisanra ati iṣẹ idabobo aimọ, ibora ti gbogbo awo awo pẹlu ohun elo resistance solder yoo ja si iyipada nla ninu agbara itanna ni apẹrẹ microstrip. Generally, solderdam is used as welding resistance layer.

Ti o ko ba faramọ pẹlu awọn ọna wọnyi, kan si ẹlẹrọ apẹrẹ ti o ni iriri ti o ti ṣiṣẹ lori awọn igbimọ Circuit makirowefu fun ologun. You can also discuss with them what price range you can afford. Fun apẹẹrẹ, o jẹ eto-ọrọ-aje diẹ sii lati lo apẹrẹ microstrip Coplanar ti o ni atilẹyin Ejò ju apẹrẹ ṣiṣan lọ, ati pe o le jiroro eyi pẹlu wọn lati gba imọran ti o dara julọ. Awọn onimọ -ẹrọ to dara le ma lo lati ronu nipa idiyele, ṣugbọn imọran wọn le wulo pupọ. Yoo jẹ iṣẹ igba pipẹ lati ṣe ikẹkọ awọn ẹlẹrọ ọdọ ti ko faramọ pẹlu awọn ipa RF ati pe ko ni iriri ni ṣiṣe pẹlu awọn ipa RF.

Ni afikun, awọn solusan miiran le gba, gẹgẹbi imudarasi awoṣe kọnputa lati ni anfani lati mu awọn ipa RF.

Isopọ PCB pẹlu awọn ẹrọ ita

A le ro bayi pe a ti yanju gbogbo awọn iṣoro iṣakoso ifihan lori ọkọ ati lori awọn isopọ ti awọn paati ọtọ. Nitorinaa bawo ni o ṣe yanju iṣoro titẹ sii/iṣoro ifihan lati igbimọ Circuit si okun waya ti n sopọ ẹrọ latọna jijin naa? TrompeterElectronics, olupilẹṣẹ ninu imọ -ẹrọ okun coaxial, n ṣiṣẹ lori iṣoro yii ati pe o ti ni ilọsiwaju diẹ ninu pataki (eeya 3). Also, take a look at the electromagnetic field shown in Figure 4 below. Ni ọran yii, a ṣakoso iyipada lati microstrip si okun coaxial. Ninu awọn kebulu coaxial, awọn fẹlẹfẹlẹ ilẹ ti wa ni idapo ni awọn oruka ati ni aaye deede. Ni awọn microbelts, fẹlẹfẹlẹ ilẹ ni isalẹ laini ti n ṣiṣẹ. Eyi ṣafihan awọn ipa eti kan ti o nilo lati ni oye, asọtẹlẹ, ati gbero ni akoko apẹrẹ. Nitoribẹẹ, aiṣedeede yii tun le ja si ipadasẹhin ati pe o gbọdọ dinku lati yago fun ariwo ati kikọlu ifihan.

Isakoso ti iṣoro ikọlu inu kii ṣe iṣoro apẹrẹ ti o le foju pa. Ainilara naa bẹrẹ ni oke ti igbimọ Circuit, kọja nipasẹ apapọ asomọ si apapọ, ati pari ni okun coaxial. Nitori ikọlu yatọ pẹlu igbohunsafẹfẹ, ipo igbohunsafẹfẹ ti o ga julọ, iṣakoso imukuro ti o nira sii jẹ. The problem of using higher frequencies to transmit signals over broadband appears to be the main design problem.