Antennas yog rhiab heev rau lawv ib puag ncig. Therefore, when there is an antenna on the PCB, tus tsim layout yuav tsum coj tus kav hlau txais xov yuav tsum tau mus rau hauv tus account, raws li qhov no yuav cuam tshuam rau lub wireless kev ua tau zoo ntawm lub cuab yeej. Great care should be taken when integrating antennas into new designs. Txawm tias cov khoom siv, cov khaubncaws sab nraud povtseg thiab tuab ntawm PCB tuaj yeem cuam tshuam rau kev ua haujlwm ntawm lub kav hlau txais xov.

Tso lub kav hlau txais xov los txhim kho kev ua haujlwm

Cov kav hlau txais xov ua haujlwm nyob rau hauv ntau hom, thiab nyob ntawm seb tus kav hlau txais xov radiate li cas, lawv yuav tsum tau muab tso rau hauv cov haujlwm tshwj xeeb – nyob rau sab luv, sab ntev, lossis kaum ntawm PCB.

Feem ntau, lub kaum sab xis ntawm PCB yog qhov chaw zoo los tso lub kav hlau txais xov. Qhov no yog vim lub ces kaum txoj hauj lwm tso cai rau lub kav hlau txais xov muaj qhov khoob hauv tsib qhov kev taw qhia spatial, thiab lub kav hlau txais xov pub yog nyob rau hauv lub thib rau kev taw qhia.

Kav hlau txais xov manufacturers muab cov kav hlau txais xov tsim kev xaiv rau ntau txoj haujlwm, yog li cov neeg tsim khoom tuaj yeem xaiv cov kav hlau txais xov uas zoo tshaj plaws rau lawv qhov teeb tsa. Typically, the manufacturer’s data sheet shows a reference design that, if followed, provides very good performance.

Product designs for 4G and LTE typically use multiple antennas to build MIMO systems. In such designs, when multiple antennas are used at the same time, the antennas are usually placed at different corners of the PCB

Nws yog ib qho tseem ceeb kom tsis txhob muab cov khoom nyob rau hauv qhov chaw ze ze ntawm lub kav hlau txais xov vim tias lawv tuaj yeem cuam tshuam rau nws qhov kev ua tau zoo. Yog li ntawd, tus kav hlau txais xov specification yuav qhia qhov luaj li cas ntawm thaj chaw tshwj tseg, uas yog thaj chaw nyob ze thiab ib ncig ntawm lub kav hlau txais xov uas yuav tsum tau ceev kom deb ntawm cov khoom siv hlau. This will apply to each layer in the PCB. Tsis tas li ntawd, tsis txhob muab cov khoom sib txuas lossis txawm tias nruab cov ntsia hlau hauv qhov chaw no ntawm txhua txheej ntawm lub rooj tsavxwm.

The antenna radiates to the ground plane, and the ground plane is related to the frequency at which the antenna operates. Yog li ntawd, nws yog ib qho tseem ceeb kom muab qhov loj me thiab qhov chaw rau lub dav hlau hauv av ntawm cov kav hlau txais xov xaiv.

Dav hlau dav hlau

Qhov loj ntawm lub dav hlau hauv av yuav tsum tau coj mus rau hauv tus account txhua cov xov hlau uas siv los sib txuas lus nrog cov cuab yeej thiab cov roj teeb lossis cov hlua hluav taws xob siv los siv lub zog ntawm lub cuab yeej. If the grounding plane is of the right size, ensure that cables and batteries connected to the device have less impact on the antenna

Some antennas are related to the grounding plane, which means that the PCB itself becomes the grounding part of the antenna to balance the antenna current, and the lower layer of the PCB may affect the performance of the antenna. Hauv qhov no, nws yog ib qho tseem ceeb tsis txhob tso cov roj teeb lossis LCDS ze ntawm lub kav hlau txais xov.

Cov chaw tsim khoom cov ntaub ntawv yuav tsum nco ntsoov qhia seb lub kav hlau txais xov yuav tsum muaj hluav taws xob hauv av thiab, yog tias muaj, qhov loj ntawm lub dav hlau hauv av xav tau. This may mean that the gap area should surround the antenna.

Ze rau lwm cov khoom siv PCB

Nws yog ib qho tseem ceeb kom khaws lub kav hlau txais xov kom deb ntawm lwm yam khoom uas yuav cuam tshuam rau txoj kev kav hlau txais xov radiates. One thing to watch out for is batteries; LCD metal components, such as USB, HDMI and Ethernet connectors; Thiab tsis muaj suab nrov lossis kev kub ceev hloov cov khoom cuam tshuam txog kev hloov cov khoom siv hluav taws xob.

Qhov kev ncua deb ntawm tus kav hlau txais xov thiab lwm yam sib txawv raws li qhov siab ntawm cov khoom. In general, if a line is drawn at an 8 degree Angle to the bottom of the antenna, the safe distance between the component and the antenna if it is below the line.

Yog tias muaj lwm lub kav hlau txais xov ua haujlwm ntawm cov zaus zoo sib xws hauv ib puag ncig, nws yuav ua rau ob lub kav hlau txais xov kom detune, vim tias lawv cuam tshuam rau ib leeg. Peb pom zoo kom txo qhov no los ntawm kev cais tsawg kawg -10 dB kav hlau txais xov ntawm zaus mus txog 1 GHz thiab tsawg kawg -20 dB kav hlau txais xov ntawm 20 GHz. Qhov no tuaj yeem ua tau los ntawm kev tawm ntau qhov chaw ntawm lub kav hlau txais xov lossis los ntawm kev tig lawv kom lawv muab tso rau ntawm 90 lossis 180 degrees sib nrug ntawm ib leeg.

Tsim cov kab sib kis

Cov kab sib kis yog rf cables uas xa RF zog mus rau thiab los ntawm tus kav hlau txais xov kom xa cov teeb liab mus rau hauv xov tooj cua. Cov kab sib kis yuav tsum tau tsim los ua 50, txwv tsis pub lawv tuaj yeem cuam tshuam cov teeb liab rov qab rau hauv xov tooj cua thiab ua rau poob ntawm qhov teeb meem-rau- suab nrov piv (SNR), uas tuaj yeem ua rau cov neeg txais xov tooj cua tsis muaj nuj nqis. Reflection yog ntsuas raws li qhov voltage sawv yoj piv (VSWR). A good PCB design will exhibit suitable VSWR measurements that can be taken when testing the antenna.

Peb pom zoo kom ua tib zoo tsim cov kab sib kis. Ua ntej, cov kab sib txuas yuav tsum ncaj, vim yog tias nws muaj cov fab lossis khoov, nws yuav ua rau poob. Los ntawm kev muab cov perforations sib npaug ntawm ob sab ntawm cov hlau, lub suab nrov thiab cov teeb liab poob uas yuav cuam tshuam rau cov kav hlau txais xov kev ua tau zoo tuaj yeem khaws cia rau theem qis, vim tias kev ua tau zoo tuaj yeem txhim kho los ntawm kev sib cais cov suab nrov propagating nyob ze ntawm cov xov hlau lossis hauv av txheej.

Cov kab sib kis zoo dua tuaj yeem ua rau poob ntau dua. Lub RF sib txuam tivthaiv thiab qhov dav ntawm cov kab sib kis tau siv los kho cov kav hlau txais xov kom ua haujlwm ntawm tus yam ntxwv impedance ntawm 50 ω. Qhov luaj li cas ntawm cov kab kis tau tus mob cuam tshuam rau kev ua tau zoo, thiab cov kab sib kis yuav tsum yog luv li sai tau rau cov kav hlau txais xov zoo.

Yuav ua li cas kom tau txais kev ua tau zoo?

Yog tias koj tso cai rau lub dav hlau hauv av thiab tso lub kav hlau txais xov rau hauv txoj haujlwm zoo, koj tau pib zoo, tab sis muaj ntau yam ntxiv uas koj tuaj yeem ua tau los txhim kho cov kav hlau txais xov. Koj tuaj yeem siv lub network sib koom ua ke los kho tus kav hlau txais xov – qhov no yuav them rau qee yam rau txhua yam uas yuav cuam tshuam rau lub kav hlau txais xov.

Qhov tseem ceeb RF tivthaiv yog lub kav hlau txais xov, uas phim lub network thiab nws cov zis RF. Ib tug configuration uas tso cov khoom nyob ze yuav txo cov teeb liab poob. Ib yam li ntawd, yog tias koj tus qauv tsim muaj xws li kev sib koom ua ke, tus kav hlau txais xov yuav ua tau zoo heev yog tias nws cov hlua ntev sib xws uas tau teev tseg hauv cov chaw tsim khoom cov khoom specifications.

Lub casing nyob ib ncig ntawm PCB kuj yuav txawv. Kav hlau txais xov teeb liab tsis tuaj yeem taug kev los ntawm hlau, yog li muab lub kav hlau txais xov rau hauv lub tsev hlau lossis vaj tsev nrog cov khoom hlau yuav tsis ua tiav.

Tsis tas li ntawd, ceev faj thaum muab cov kav hlau txais xov ze ze ntawm cov yas, vim qhov no tuaj yeem ua rau muaj kev puas tsuaj loj rau cov kav hlau txais xov. Qee cov plastics (piv txwv li, fiberglass puv nylon) yog qhov tsis zoo thiab tuaj yeem lwj mus rau ANTENNA’s RF teeb liab. Yas muaj qhov dielectric ntau dua qhov tsis tu ncua ntawm huab cua, uas tuaj yeem cuam tshuam rau lub teeb liab. Qhov no txhais tau hais tias tus kav hlau txais xov yuav kaw qhov dielectric ntau dua, ua kom lub zog ntawm lub kav hlau txais xov ntev thiab txo qhov zaus ntawm cov kav hlau txais xov hluav taws xob.