The interconnect of bọọdụ sekit biri ebi sistemụ gụnyere bọọdụ mgbawa-na-sekit, njikọta n’ime PCB yana njikọta n’etiti PCB na ngwaọrụ mpụga. 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.

Enwere akara na -ahazi bọọdụ sekit e biri ebi ka ọ na -abawanye ugboro ugboro. 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.

Usoro ihe eji arụ ọrụ RF ga -enwerịrị ike ijikwa mmetụta ubi elektrọnik siri ike nke a na -ebutekarị na ugboro ugboro dị elu. Ogige elektrọnik ndị a nwere ike ibute akara na ahịrị mgbama dị n’akụkụ ma ọ bụ ahịrị PCB, na -akpata crosstalk na -adịghị mma (nnyonye anya na mkpọtụ zuru oke) na imebi arụmọrụ sistemụ. 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. Mgbama ọ bụla e gosipụtara ga -agbada ịdị mma nke mgbama n’ihi na ọdịdị nke mgbama ntinye na -agbanwe.

Ọ bụ ezie na sistemụ dijitalụ na -anabatakarị mmejọ n’ihi na ha na -emeso naanị akara 1 na 0, harmonics a na -eme mgbe ụda na -ebili ngwa ngwa na -eme ka mgbama ahụ ghara ịdị ike na ugboro ugboro dị elu. Ọ bụ ezie na mgbazi njehie na -aga n’ihu nwere ike iwepụ ụfọdụ mmetụta adịghị mma, a na -eji akụkụ nke sistemụ bandwidth na -ebufe data ejighị n’aka, na -ebute mbibi arụmọrụ. A better solution is to have RF effects that help rather than detract from signal integrity. It is recommended that the total return loss at the highest frequency of a digital system (usually a poor data point) be -25dB, equivalent to a VSWR of 1.1.

PCB design aims to be smaller, faster and less costly. For RFPCB, high-speed signals sometimes limit the miniaturization of PCB designs. At present, the main method to solve the crosseration problem is to carry out ground connection management, conduct spacing between wiring and reduce lead inductance. Ụzọ bụ isi iji belata mfu nloghachi bụ isonye na impedance. Usoro a gụnyere njikwa dị mma nke ihe mkpuchi ihe na ikewapụ nke ahịrị mgbama arụ ọrụ na ahịrị ala, ọkachasị n’etiti steeti akara akara na ala.

N’ihi na njikọta bụ njikọ na -esighi ike na eriri sekit, na imewe RF, njirimara elektrọnik nke njikọ njikọta bụ isi nsogbu na -eche ihu injinịa, ekwesịrị inyocha ebe njikọ ọ bụla ma dozie nsogbu ndị dị. Njikọ bọọdụ sekit na-agụnye njikọta bọọdụ mgbawa, njikọta PCB na ntinye ntinye/mmepụta n’etiti PCB na ngwaọrụ mpụga.

I. Njikọ n’etiti mgbawa na bọọdụ PCB

Ma azịza a ọ na -arụ ọrụ ma ọ bụ na ọ naghị arụ ọrụ, ọ bịara ndị bịara ya anya na teknụzụ imewe IC dị n’ihu teknụzụ imebe PCB maka ngwa hf.

Njikọ PCB

Usoro na ụzọ maka imepụta PCB hf dị ka ndị a:

1. Ekwesịrị iji akụkụ 45 ° maka nkuku ahịrị nnyefe iji belata mfu nloghachi (FIG 1);

2 mkpuchi mgbe niile uru dị ka ọkwa nke nditịm na-achịkwa elu arụmọrụ insulating circuit mbadamba. This method is beneficial for effective management of electromagnetic field between insulating material and adjacent wiring.

3. Ekwesịrị ịkwalite nkọwa nkọwa PCB maka etching ziri ezi. Tụlee ịkọwapụta njehie obosara ahịrị zuru oke nke +/- 0.0007 sentimita, na-ejikwa okpuru ala na akụkụ nke ụdị wired na ịkọwa ọnọdụ plating akụkụ mgbidi. 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. Enwere mgbata mgbata na ụzọ na -apụta. Zere iji ihe ndị nwere ihe ndu eme ihe. Maka gburugburu ugboro ugboro, ọ kacha mma iji ihe ndị etinyere n’elu.

5. Maka mgbaama site na oghere, zere iji usoro PTH na efere dị nro, n’ihi na usoro a nwere ike bute inductance na oghere. 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. Provide abundant ground layers. Moulded holes are used to connect these grounding layers to prevent 3d electromagnetic fields from affecting the circuit board.

7. Ka ịhọrọ nickel plating ma ọ bụ usoro itinye ọla edo emikpu, ejikwala usoro HASL plating. This electroplated surface provides a better skin effect for high-frequency currents (Figure 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. Agbanyeghị, n’ihi ejighị n’aka na ọkpụrụkpụ na arụ ọrụ mkpuchi amaghị, ikpuchi ihe niile dị na efere ga -ebute nnukwu mgbanwe na ọkụ elektrọnik na imewe microstrip. Generally, solderdam is used as welding resistance layer.

Ọ bụrụ na ịmabeghị ụzọ ndị a, gakwuru onye injinia nwere ahụmịhe nke rụworo ọrụ na bọọdụ sekit microwave maka ndị agha. You can also discuss with them what price range you can afford. Dịka ọmụmaatụ, ọ bara uru karịa iji igwe microstrip Coplanar nke ọla kọpa na-akwado karịa imewe eriri, ị nwere ike soro ha kpaa maka nke a ka ị nweta ndụmọdụ ka mma. Ezi ndị injinia nwere ike ha agaghị eche echiche maka ọnụ ahịa, mana ndụmọdụ ha nwere ike inye aka. Ọ ga-abụ ọrụ ga-ewe ogologo oge ịzụ ndị injinia na-eto eto na-amaghị mmetụta RF na enweghị ahụmịhe na-emeso mmetụta RF.

Na mgbakwunye, enwere ike ịnabata usoro ndị ọzọ, dị ka ịkwalite ụdị kọmputa iji nwee ike ijikwa nsonaazụ RF.

PCB na njikọ na ngwaọrụ mpụga

Anyị nwere ike iche ugbu a na anyị edozila nsogbu njikwa akara na bọọdụ yana njikọta nke ihe dị iche. Yabụ kedu ka ị ga -esi dozie nsogbu ntinye/mmepụta mgbaama site na bọọdụ sekit gaa na waya na -ejikọ ngwaọrụ dịpụrụ adịpụ? TrompeterElectronics, onye na -emepụta ihe na teknụzụ eriri coaxial, na -arụ ọrụ na nsogbu a wee nwee ọganiihu dị mkpa (ọgụgụ 3). Also, take a look at the electromagnetic field shown in Figure 4 below. N’okwu a, anyị na -ejikwa ntụgharị site na microstrip gaa na eriri coaxial. N’ime eriri coaxial, a na -etinye akwa ala na mgbaaka ma kewaa ya. Na microbelts, oyi akwa dị n’okpuru ahịrị nọ n’ọrụ. Nke a na -ewebata mmetụta ụfọdụ dị mkpa nke a ga -aghọta, buru amụma, ma tụlee ya n’oge imewe. N’ezie, ndakọrịta a nwekwara ike ibute azụ azụ na a ga -ebelatarịrị ya iji zere mkpọtụ na nnyonye anya mgbaama.

Njikwa nsogbu impedance nke ime abụghị nsogbu imewe nke enwere ike ileghara anya. The impedance starts at the surface of the circuit board, passes through a solder joint to the joint, and ends at the coaxial cable. Ebe ọ bụ na impedance na -adịgasị iche, ugboro ole ọ dị elu, ka njigide impedance siri ike karịa. The problem of using higher frequencies to transmit signals over broadband appears to be the main design problem.