{"id":29,"date":"2024-11-26T16:38:11","date_gmt":"2024-11-26T13:38:11","guid":{"rendered":"https:\/\/ta9ea.com\/?p=29"},"modified":"2024-11-26T16:38:11","modified_gmt":"2024-11-26T13:38:11","slug":"5ghz-frekans-carpani","status":"publish","type":"post","link":"https:\/\/ta9ea.com\/?p=29","title":{"rendered":"5GHz Frekans \u00c7arpan\u0131"},"content":{"rendered":"

Mikrodalga bantlar\u0131 i\u00e7in sinyal \u00fcrete\u00e7leri pahal\u0131d\u0131r ve elde edilmesi zordur, \u00f6zellikle L Band\u0131 \u00fczerinde. Harmonik \u00fcretim ve filtrelemeye dayanan bu frekans \u00e7arpan\u0131, d\u00fc\u015f\u00fck par\u00e7a say\u0131s\u0131yla \u00e7al\u0131\u015f\u0131r ve ev laboratuvarlar\u0131ndaki maksimum frekanslar\u0131 kolayca geni\u015fletir.<\/p>\n

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Modern bir BFP420 BJT, kollekt\u00f6r\u00fcndeki giri\u015f sinyalinin g\u00fc\u00e7l\u00fc harmoniklerini \u00fcreten doymu\u015f bir amplifikat\u00f6r olarak kullan\u0131l\u0131r, b\u00f6ylece 2. harmonik frekans\u0131n iki kat\u0131na \u00e7\u0131kar\u0131lmas\u0131 i\u00e7in istenen \u00e7\u0131k\u0131\u015ft\u0131r. Giri\u015f sinyalinin transist\u00f6r\u00fc P1dB \u00fczerinde uyarmas\u0131 gerekir. 0dBm’lik bir giri\u015f g\u00fcc\u00fc iyi bir \u00e7al\u0131\u015fma noktas\u0131na ula\u015f\u0131r ve g\u00fczel bir yuvarlak de\u011ferdir. Yine de, daha y\u00fcksek giri\u015f g\u00fc\u00e7leri 2. harmonik g\u00fcc\u00fcn tam doyumuna kadar daha y\u00fcksek \u00e7\u0131k\u0131\u015f \u00fcretecektir.<\/span><\/p>\n

Bir lambda\/4 \u00f6nyarg\u0131l\u0131 tee, transist\u00f6r\u00fc kolayca \u00f6nyarg\u0131lar ve ayn\u0131 zamanda \u00e7\u0131k\u0131\u015f frekans\u0131 i\u00e7in y\u00fcksek bir empedans sa\u011flar. DC \u00e7al\u0131\u015fma noktas\u0131 620R ve 6k2 diren\u00e7leri taraf\u0131ndan yap\u0131land\u0131r\u0131l\u0131r. Seri haldeki iki taban direnci, taban RF enerjisinin izolasyonuna yard\u0131mc\u0131 olur ve aralar\u0131nda bir mikro \u015ferit bask\u0131l\u0131 ind\u00fckt\u00f6r \u00f6nerilir. Farkl\u0131 bir \u00f6nyarg\u0131 noktas\u0131 se\u00e7ilirse, modern BFP420’nin maksimum \u00e7ok d\u00fc\u015f\u00fck kollekt\u00f6r voltaj\u0131n\u0131n a\u015f\u0131lmamas\u0131na dikkat edilmelidir.<\/span><\/p>\n

Temel ve istenmeyen harmonikler, mikro\u015ferit kuplajl\u0131 hat bant ge\u00e7i\u015f filtresiyle filtrelenir. Lambda\/2 rezonat\u00f6rleri ve lambda\/4 kenar kupl\u00f6rlerine dayanan genel yap\u0131, \u00e7ok az veya hi\u00e7 ayarlama gerektirmez. Yine de, gerekirse, rezonat\u00f6rlerin uzunlu\u011funu uzatmak i\u00e7in k\u00fc\u00e7\u00fck bak\u0131r bant par\u00e7alar\u0131 kullan\u0131labilir.<\/span><\/p>\n

Devre, hi\u00e7 giri\u015f e\u015fle\u015fmesi olmasa bile ger\u00e7ekten iyi \u00e7al\u0131\u015f\u0131yor ve g\u00fc\u00e7l\u00fc bir 5GHz @ -5dBm \u00e7\u0131k\u0131\u015f sinyali \u00fcretiyor. K\u00fc\u00e7\u00fck bir a\u00e7\u0131k u\u00e7lu e\u015fle\u015fen \u00e7\u0131k\u0131nt\u0131 olarak \u00e7al\u0131\u015fan dikd\u00f6rtgen bir bak\u0131r bant par\u00e7as\u0131yla biraz daha y\u00fcksek \u00e7\u0131k\u0131\u015f g\u00fcc\u00fc elde edildi. Uzunluk ve geni\u015flik deneysel olarak \u00e7\u0131k\u0131\u015f g\u00fcc\u00fcn\u00fc maksimize etmek i\u00e7in se\u00e7ildi (bu, daha iyi giri\u015f VSWR anlam\u0131na gelmez). Saplama muhtemelen lambda\/4’e yak\u0131n bir uzunlu\u011fa sahip olacak ve \u00e7\u0131k\u0131\u015f frekans\u0131n\u0131 k\u0131saltacakt\u0131r.<\/span><\/p>\n

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Prototip, FR4 alt tabakadan yap\u0131lm\u0131\u015f tek katmanl\u0131 bir PCB \u00fczerinde bak\u0131r bantla yap\u0131ld\u0131. Mikrodalga \u00e7al\u0131\u015fmas\u0131 i\u00e7in \u00f6nerilmese bile, FR4 yard\u0131mc\u0131 olur ve daha y\u00fcksek kay\u0131plar nedeniyle transist\u00f6r\u00fcn kendi kendine sal\u0131n\u0131m\u0131 ve sahte rezonans modlar\u0131 olas\u0131l\u0131\u011f\u0131n\u0131 azalt\u0131r. Ge\u00e7i\u015fler, PCB’yi 3,5 mm’lik bir matkapla delerek, alt ucu bak\u0131r bantla kapatarak ve deli\u011fi lehimle doldurarak yap\u0131l\u0131r ve iyi bir mikrodalga GND ba\u011flant\u0131s\u0131 sa\u011flan\u0131r.<\/span><\/p>\n

En iyi performans\u0131 elde etmek i\u00e7in \u00e7\u0131k\u0131\u015f filtresi kuplaj\u0131 deneysel olarak de\u011fi\u015ftirilebilir. Genel bir kural olarak, merkezdeki rezonat\u00f6rler kenardakilerden daha gev\u015fek kuplajla yerle\u015ftirilir (resimde g\u00f6r\u00fcld\u00fc\u011f\u00fc gibi daha y\u00fcksek fiziksel ayr\u0131m). SMA konnekt\u00f6rleri sinyalleri karta sokmak ve \u00e7\u0131karmak i\u00e7in kullan\u0131l\u0131r.<\/span><\/p>\n

Bak\u0131r bantl\u0131 yap\u0131, herhangi bir frekans\u0131n frekans \u00e7arpanlar\u0131n\u0131n kolay ve h\u0131zl\u0131 prototiplenmesine olanak tan\u0131r, \u00e7\u0131k\u0131\u015f filtresi ve \u00f6nyarg\u0131 te’si de\u011fi\u015fikli\u011fe ihtiya\u00e7 duyan ana par\u00e7alard\u0131r. \u00dc\u00e7l\u00fcler ve daha y\u00fcksek dereceli tasar\u0131mlar, 3. ve hatta daha y\u00fcksek harmonikleri filtrelemelerine ra\u011fmen ayn\u0131 \u00e7al\u0131\u015fma prensibini izler.<\/span><\/p>\n

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Frekans \u00c7arpan\u0131 Giri\u015f G\u00fcc\u00fc ve \u00c7\u0131k\u0131\u015f G\u00fcc\u00fc.<\/span><\/figcaption><\/figure>\n

Giri\u015f uyar\u0131m\u0131n\u0131n \u00e7\u0131k\u0131\u015f g\u00fcc\u00fcne oran\u0131, 0dBm’nin maksimum kullan\u0131labilir \u00e7\u0131k\u0131\u015f ile s\u0131k\u0131\u015ft\u0131rma davran\u0131\u015f\u0131 aras\u0131nda iyi bir uzla\u015fma oldu\u011funu g\u00f6sterir. 2,5GHz giri\u015f sinyalinin \u00e7\u0131k\u0131\u015f s\u0131z\u0131nt\u0131s\u0131, -33dBc’de (ana \u00e7\u0131k\u0131\u015f tonundan 33dB daha d\u00fc\u015f\u00fck) kendini g\u00f6sterir ve daha y\u00fcksek giri\u015flerle do\u011frusal olarak artar. \u00c7al\u0131\u015fman\u0131n k\u00fc\u00e7\u00fck sinyal b\u00f6lgesi i\u00e7in (-6dBm giri\u015fe kadar) \u00e7\u0131k\u0131\u015f tonunun giri\u015ften iki kat daha h\u0131zl\u0131 b\u00fcy\u00fcd\u00fc\u011f\u00fcn\u00fc belirtmek ilgin\u00e7tir, \u00e7\u00fcnk\u00fc 2. harmonik, anl\u0131k kollekt\u00f6r voltaj\u0131n\u0131n polinom g\u00f6sterimindeki kareli terimden kaynaklan\u0131r.<\/span><\/p>\n

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Frekans \u00c7arpan\u0131 \u00c7\u0131k\u0131\u015f G\u00fcc\u00fc ve Geri D\u00f6n\u00fc\u015f Kayb\u0131 vs. Kollekt\u00f6r Sapmas\u0131.<\/span><\/figcaption><\/figure>\n

Kolekt\u00f6r \u00f6nyarg\u0131 ak\u0131m\u0131n\u0131n bir taramas\u0131, giri\u015f d\u00f6n\u00fc\u015f kayb\u0131n\u0131n ve \u00e7\u0131k\u0131\u015f g\u00fcc\u00fcn\u00fcn davran\u0131\u015f\u0131n\u0131 g\u00f6sterir. Temel do\u011frusal olmayan \u00e7al\u0131\u015fma prensibi, optimizasyon i\u00e7in iki farkl\u0131 nokta sa\u011flar. En iyi giri\u015f e\u015fle\u015fmesi, daha y\u00fcksek \u00e7\u0131k\u0131\u015f\u0131 \u00fcretmeyecek olan 5,5 mA yak\u0131n\u0131nda ger\u00e7ekle\u015fir. Bu nedenle, \u00f6nyarg\u0131 noktas\u0131 farkl\u0131 hedefler aras\u0131nda bir ge\u00e7i\u015f noktas\u0131d\u0131r.<\/span><\/p>\n

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0dBm giri\u015f ve 6mA kollekt\u00f6r \u00f6nyarg\u0131s\u0131 ile \u00e7\u0131k\u0131\u015f spektrumu.<\/span><\/figcaption><\/figure>\n

\u00c7\u0131k\u0131\u015f spektrumu, 5GHz \u00e7\u0131k\u0131\u015f\u0131n\u0131 ve 2.5GHz’deki giri\u015f s\u0131z\u0131nt\u0131s\u0131n\u0131 i\u00e7eren genel olarak temiz bir \u015fekle sahiptir. Bununla birlikte, muhtemelen parazitik sal\u0131n\u0131m modlar\u0131ndan kaynaklanan, giri\u015f frekans\u0131n\u0131n korelasyonsuz katlar\u0131nda baz\u0131 sahte sinyaller mevcuttur. Daha derin bir ara\u015ft\u0131rma, sahte sinyalin k\u00f6kenini anlamaya yard\u0131mc\u0131 olacakt\u0131r, yine de, d\u00fc\u015f\u00fck genlik bir endi\u015fe kayna\u011f\u0131 gibi g\u00f6r\u00fcnm\u00fcyor.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Mikrodalga bantlar\u0131 i\u00e7in sinyal \u00fcrete\u00e7leri pahal\u0131d\u0131r ve elde edilmesi zordur, \u00f6zellikle L Band\u0131 \u00fczerinde. Harmonik \u00fcretim ve filtrelemeye dayanan bu frekans \u00e7arpan\u0131, d\u00fc\u015f\u00fck par\u00e7a say\u0131s\u0131yla […]<\/p>\n","protected":false},"author":1,"featured_media":35,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-29","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-genel"],"_links":{"self":[{"href":"https:\/\/ta9ea.com\/index.php?rest_route=\/wp\/v2\/posts\/29","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ta9ea.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ta9ea.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ta9ea.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ta9ea.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=29"}],"version-history":[{"count":0,"href":"https:\/\/ta9ea.com\/index.php?rest_route=\/wp\/v2\/posts\/29\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ta9ea.com\/index.php?rest_route=\/"}],"wp:attachment":[{"href":"https:\/\/ta9ea.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=29"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ta9ea.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=29"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ta9ea.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=29"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}