{"id":321,"date":"2016-12-04T12:11:16","date_gmt":"2016-12-04T11:11:16","guid":{"rendered":"http:\/\/www.morong.info\/?p=321"},"modified":"2016-12-04T12:16:01","modified_gmt":"2016-12-04T11:16:01","slug":"fresnelova-zona","status":"publish","type":"post","link":"https:\/\/www.morong.info\/?p=321","title":{"rendered":"Fresnelova z\u00f3na"},"content":{"rendered":"

Fresnelova z\u00f3na<\/p>\n

T\u011bchto z\u00f3n je v\u00edce, ale nejd\u016fle\u017eit\u011bj\u0161\u00ed je pro n\u00e1s 60 % z prvn\u00ed Fresnelovy z\u00f3ny. V\u00fdpo\u010det je relativn\u011b jednoduch\u00fd. Polom\u011br kulov\u00e9 plochy (nejvy\u0161\u0161\u00ed vzd\u00e1lenost v metrech) mezi st\u0159edem a krajem je 60 % \u00d7 17,3 \u00d7 odmocnina (D\/4f) kde D je vzd\u00e1lenost v km, f je frekvence v GHz.
\nZde je p\u0159ehled ji\u017e vypo\u010d\u00edtan\u00fdch hodnot:
\n100 m : 1,8 m
\n200 m : 2,5 m
\n300 m : 3,1 m
\n500 m : 4,0 m
\n700 m : 4,7 m
\n1000 m : 5,6 m
\n1500m : 6,9 m
\n2000m : 8,0 m
\n3000 m : 9,8 m
\n4000 m : 11,3 m<\/p>\n

Nap\u0159. trasa dlouh\u00e1 1 km (maxim\u00e1ln\u00ed pr\u016fm\u011br Fresnelovy z\u00f3ny je 5,6 m) m\u00e1 ji\u017e po prvn\u00edch 100 metrech pr\u016fm\u011br Fresnelovy z\u00f3ny 3,4 m. Pou\u017eijete-li ant\u00e9nu na ty\u010di o d\u00e9lce 1,5 m nad st\u0159echu, pak nach\u00e1z\u00ed-li se ve vzd\u00e1lenosti 100 m stejn\u011b vysok\u00fd d\u016fm, zasahuje u\u017e do Va\u0161\u00ed Fresnelovy z\u00f3ny.
\nNaru\u0161en\u00e1 Fresnelova z\u00f3na v\u011bt\u0161inou nem\u00e1 za n\u00e1sledek p\u0159\u00edli\u0161 podstatn\u00e9 sn\u00ed\u017een\u00ed \u00farovn\u011b sign\u00e1lu. Ale proto\u017ee se pak „vz\u00e1jemn\u011b ovliv\u0148uj\u00ed odrazy“, sni\u017euje se kvalita p\u0159en\u00e1\u0161en\u00e9ho datov\u00e9ho toku (vy\u0161\u0161\u00ed ztr\u00e1tovost paket\u016f, ni\u017e\u0161\u00ed dosa\u017eiteln\u00e1 rychlost). Proto by se m\u011blo v\u011bnovat \u00fasil\u00ed k tomu, aby bylo voln\u00fdch alespo\u0148 60 % pr\u016fm\u011bru Fresnelovy z\u00f3ny. V\u011bt\u0161inou sta\u010d\u00ed um\u00edstit ant\u00e9nu v\u00fd\u0161e. <\/p>\n

\"fresnel1\"
\n\"fresnel2\"<\/p>\n

Zdroj: www.ovanet.cz<\/a>
\nZdroj: internet.vprdeli.com<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Fresnelova z\u00f3na T\u011bchto z\u00f3n je v\u00edce, ale nejd\u016fle\u017eit\u011bj\u0161\u00ed je pro n\u00e1s 60 % z prvn\u00ed Fresnelovy z\u00f3ny. V\u00fdpo\u010det je relativn\u011b jednoduch\u00fd. Polom\u011br kulov\u00e9 plochy (nejvy\u0161\u0161\u00ed vzd\u00e1lenost v metrech) mezi st\u0159edem a krajem je 60 % \u00d7 17,3 \u00d7 odmocnina (D\/4f) … Cel\u00fd p\u0159\u00edsp\u011bvek →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,4],"tags":[],"class_list":["post-321","post","type-post","status-publish","format-standard","hentry","category-administrace","category-wifi"],"_links":{"self":[{"href":"https:\/\/www.morong.info\/index.php?rest_route=\/wp\/v2\/posts\/321","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.morong.info\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.morong.info\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.morong.info\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.morong.info\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=321"}],"version-history":[{"count":4,"href":"https:\/\/www.morong.info\/index.php?rest_route=\/wp\/v2\/posts\/321\/revisions"}],"predecessor-version":[{"id":329,"href":"https:\/\/www.morong.info\/index.php?rest_route=\/wp\/v2\/posts\/321\/revisions\/329"}],"wp:attachment":[{"href":"https:\/\/www.morong.info\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=321"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.morong.info\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=321"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.morong.info\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=321"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}