{"id":392157,"date":"2024-10-31T03:58:12","date_gmt":"2024-10-31T03:58:12","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/trouble-getting-correct-fdtd-plane-wave-region\/"},"modified":"2024-11-01T02:42:21","modified_gmt":"2024-11-01T02:42:21","slug":"trouble-getting-correct-fdtd-plane-wave-region","status":"answered","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/trouble-getting-correct-fdtd-plane-wave-region\/","title":{"rendered":"Trouble Getting Correct FDTD Plane Wave Region"},"content":{"rendered":"<p>&lt;p&gt;&lt;span class=&#8221;ryNqvb&#8221;&gt;I am illuminating a grating with a plane wave source while using an FDTD simulation. The planesource is set below the grating, and has the same size as the grating. However, when the simulation starts, the planesource region&nbsp;&lt;\/span&gt;&lt;span class=&#8221;ryNqvb&#8221;&gt;automatically enlarged as about twice the original length. I&#8217;m wondering why it happens and how could I avoid.&lt;\/span&gt;&lt;\/p&gt;&lt;p&gt;&lt;span class=&#8221;ryNqvb&#8221;&gt;Before simulation:&lt;\/span&gt;&lt;\/p&gt;&lt;p&gt;<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/10\/31-10-2024-1730346595-mceclip0.png\" width=\"481\" height=\"255\" \/>&lt;\/p&gt;&lt;p&gt;&lt;span class=&#8221;ryNqvb&#8221;&gt;After simulation:&lt;\/span&gt;&lt;\/p&gt;&lt;p&gt;<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/10\/31-10-2024-1730346825-mceclip1.png\" width=\"480\" height=\"257\" \/>&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-392157","topic","type-topic","status-answered","hentry","topic-tag-3DFDTD-1","topic-tag-simulation","topic-tag-source-2"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["476840","33648"],"_bbp_author_ip":["147.78.247.28"],"_btv_view_count":["315"],"_bbp_topic_status":["answered"],"_bbp_topic_id":["392157"],"_bbp_forum_id":["27833"],"_bbp_engagement":["33648"],"_bbp_voice_count":["1"],"_bbp_last_reply_id":["392312"],"_bbp_last_active_id":["392312"],"_bbp_last_active_time":["2024-10-31 19:58:17"]},"test":"1668134855qq-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/392157","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":1,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/392157\/revisions"}],"predecessor-version":[{"id":392344,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/392157\/revisions\/392344"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=392157"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}