{"id":382702,"date":"2024-09-15T02:51:30","date_gmt":"2024-09-15T02:51:30","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/180-degree-phase-shift-when-measuring-s21\/"},"modified":"2024-09-15T02:51:30","modified_gmt":"2024-09-15T02:51:30","slug":"180-degree-phase-shift-when-measuring-s21","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/180-degree-phase-shift-when-measuring-s21\/","title":{"rendered":"180 Degree Phase Shift When Measuring S21"},"content":{"rendered":"<p>&lt;p&gt;Hi,&lt;\/p&gt;&lt;p&gt;I&#8217;m running a parametric sweep by rotating a probe around a central horn antenna. I&#8217;m showing a few images below for illustration.&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/09\/15-09-2024-1726367016-mceclip0.png\" \/>&lt;\/p&gt;&lt;p&gt;Fig 1: At Theta = 0 degrees.&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/09\/15-09-2024-1726367219-mceclip1.png\" \/>&lt;\/p&gt;&lt;p&gt;Fig 2: At Theta = 10 degrees&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/09\/15-09-2024-1726367258-mceclip2.png\" \/>&lt;\/p&gt;&lt;p&gt;Fig 3: Theta = 20 degrees&lt;\/p&gt;&lt;p&gt;&#8230;And so on&#8230;&lt;\/p&gt;&lt;p&gt;When I measure the phase of the S21 results, I see random 180 degree shifts in the measurements. I am not able to see any pattern in these shifts either.&lt;\/p&gt;&lt;p&gt;I thought perhaps it was because I was initially using 2 FE-BI boundaries and that might be causing an issue. So I tried a single Radiation boundary instead, but that also didn&#8217;t help.&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;table style=&#8221;border-collapse: collapse; width: 186pt;&#8221; border=&#8221;0&#8243; width=&#8221;248&#8243; cellspacing=&#8221;0&#8243; cellpadding=&#8221;0&#8243;&gt;&lt;colgroup&gt;&lt;col style=&#8221;mso-width-source: userset; mso-width-alt: 3474; width: 71pt;&#8221; width=&#8221;95&#8243;&gt; &lt;col style=&#8221;mso-width-source: userset; mso-width-alt: 5595; width: 115pt;&#8221; width=&#8221;153&#8243;&gt; &lt;\/colgroup&gt;&lt;tbody&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt; width: 71pt;&#8221; width=&#8221;95&#8243; height=&#8221;20&#8243;&gt;theta_rotation [deg]&lt;\/td&gt;&lt;td style=&#8221;width: 115pt;&#8221; width=&#8221;153&#8243;&gt;S21 Phase Results [deg]&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;-10&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;101.2924367&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;-9&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;103.7009139&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;-8&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;105.601412&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;-7&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;107.5837877&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;-6&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;109.0814497&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;-5&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;110.6225511&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;-4&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;-68.19983945&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;-3&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;112.7819268&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;-2&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;-66.46548137&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;-1&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;-65.96723292&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;0&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;114.1349591&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;1&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;114.08219&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;2&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;113.6846084&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;3&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;-66.93414481&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;4&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;112.1847997&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;5&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;111.1811682&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;6&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;109.7736687&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;7&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;-71.78552943&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;8&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;106.3168243&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;9&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;104.558732&lt;\/td&gt;&lt;\/tr&gt;&lt;tr style=&#8221;height: 15.0pt;&#8221;&gt;&lt;td style=&#8221;height: 15.0pt;&#8221; align=&#8221;right&#8221; height=&#8221;20&#8243;&gt;10&lt;\/td&gt;&lt;td align=&#8221;right&#8221;&gt;102.4050767&lt;\/td&gt;&lt;\/tr&gt;&lt;\/tbody&gt;&lt;\/table&gt;&lt;p&gt;As you can see from these results, at random points the phase shifts down by ~180 degrees.&lt;\/p&gt;&lt;p&gt;For example at Theta = -4, the phase measurement is -68.2 degrees, whereas at Theta = -5 it is 110.6 degrees, and at Theta = -3 it is 112.8 degrees. The -68.2 measurement seems to be shifted down by 180 degrees (-68.2 + 180 = 111.8). 111.8 degrees seems like a more reasonable measurement. This occurs again at random points with no discernible pattern.&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;Can I please get some feedback on why this issue might be occuring and how I can fix it?&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;Thank you,&lt;\/p&gt;&lt;p&gt;Shyam&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-382702","topic","type-topic","status-publish","hentry","topic-tag-ansys-hfss","topic-tag-hfss"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 4.9.10 - aioseo.com -->\n\t<meta name=\"description\" content=\"Hi,I&#039;m running a parametric sweep by rotating a probe around a central horn antenna. I&#039;m showing a few images below for illustration.Fig 1: At Theta = 0 degrees.Fig 2: At Theta = 10 degreesFig 3: Theta = 20 degrees...And so on...When I measure the phase of the S21 results, I see random 180 degree shifts\" \/>\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<link rel=\"canonical\" href=\"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/180-degree-phase-shift-when-measuring-s21\/\" \/>\n\t<meta name=\"generator\" content=\"All in One SEO (AIOSEO) 4.9.10\" \/>\n\t\t<meta property=\"og:locale\" content=\"en_US\" \/>\n\t\t<meta property=\"og:site_name\" content=\"Ansys Learning Forum | Ansys Innovation Space\" \/>\n\t\t<meta property=\"og:type\" content=\"article\" \/>\n\t\t<meta property=\"og:title\" content=\"180 Degree Phase Shift When Measuring S21 | Ansys Learning Forum\" \/>\n\t\t<meta property=\"og:description\" content=\"Hi,I&#039;m running a parametric sweep by rotating a probe around a central horn antenna. I&#039;m showing a few images below for illustration.Fig 1: At Theta = 0 degrees.Fig 2: At Theta = 10 degreesFig 3: Theta = 20 degrees...And so on...When I measure the phase of the S21 results, I see random 180 degree shifts\" \/>\n\t\t<meta property=\"og:url\" content=\"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/180-degree-phase-shift-when-measuring-s21\/\" \/>\n\t\t<meta property=\"og:image\" content=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/09\/15-09-2024-1726367016-mceclip0.png\" \/>\n\t\t<meta property=\"og:image:secure_url\" content=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/09\/15-09-2024-1726367016-mceclip0.png\" \/>\n\t\t<meta property=\"article:published_time\" content=\"2024-09-15T02:51:30+00:00\" \/>\n\t\t<meta property=\"article:modified_time\" content=\"2024-09-15T02:51:30+00:00\" \/>\n\t\t<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n\t\t<meta name=\"twitter:title\" content=\"180 Degree Phase Shift When Measuring S21 | Ansys Learning Forum\" \/>\n\t\t<meta name=\"twitter:description\" content=\"Hi,I&#039;m running a parametric sweep by rotating a probe around a central horn antenna. I&#039;m showing a few images below for illustration.Fig 1: At Theta = 0 degrees.Fig 2: At Theta = 10 degreesFig 3: Theta = 20 degrees...And so on...When I measure the phase of the S21 results, I see random 180 degree shifts\" \/>\n\t\t<meta name=\"twitter:image\" content=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/09\/15-09-2024-1726367016-mceclip0.png\" \/>\n\t\t<script type=\"application\/ld+json\" class=\"aioseo-schema\">\n\t\t\t{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/180-degree-phase-shift-when-measuring-s21\\\/#breadcrumblist\",\"itemListElement\":[{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum#listItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/#listItem\",\"name\":\"Topics\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/#listItem\",\"position\":2,\"name\":\"Topics\",\"item\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic-tag\\\/hfss\\\/#listItem\",\"name\":\"hfss\"},\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum#listItem\",\"name\":\"Home\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic-tag\\\/hfss\\\/#listItem\",\"position\":3,\"name\":\"hfss\",\"item\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic-tag\\\/hfss\\\/\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/180-degree-phase-shift-when-measuring-s21\\\/#listItem\",\"name\":\"180 Degree Phase Shift When Measuring S21\"},\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/#listItem\",\"name\":\"Topics\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/180-degree-phase-shift-when-measuring-s21\\\/#listItem\",\"position\":4,\"name\":\"180 Degree Phase Shift When Measuring S21\",\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic-tag\\\/hfss\\\/#listItem\",\"name\":\"hfss\"}}]},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#organization\",\"name\":\"Ansys Learning Forum\",\"description\":\"Ansys Innovation Space\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/180-degree-phase-shift-when-measuring-s21\\\/#webpage\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/180-degree-phase-shift-when-measuring-s21\\\/\",\"name\":\"180 Degree Phase Shift When Measuring S21 | Ansys Learning Forum\",\"description\":\"Hi,I'm running a parametric sweep by rotating a probe around a central horn antenna. I'm showing a few images below for illustration.Fig 1: At Theta = 0 degrees.Fig 2: At Theta = 10 degreesFig 3: Theta = 20 degrees...And so on...When I measure the phase of the S21 results, I see random 180 degree shifts\",\"inLanguage\":\"en-US\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#website\"},\"breadcrumb\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/180-degree-phase-shift-when-measuring-s21\\\/#breadcrumblist\"},\"datePublished\":\"2024-09-15T02:51:30+00:00\",\"dateModified\":\"2024-09-15T02:51:30+00:00\"},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#website\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/\",\"name\":\"Ansys Learning Forum\",\"description\":\"Ansys Innovation Space\",\"inLanguage\":\"en-US\",\"publisher\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#organization\"}}]}\n\t\t<\/script>\n\t\t<!-- All in One SEO -->\n\n","aioseo_head_json":{"title":"180 Degree Phase Shift When Measuring S21 | Ansys Learning Forum","description":"Hi,I'm running a parametric sweep by rotating a probe around a central horn antenna. I'm showing a few images below for illustration.Fig 1: At Theta = 0 degrees.Fig 2: At Theta = 10 degreesFig 3: Theta = 20 degrees...And so on...When I measure the phase of the S21 results, I see random 180 degree shifts","canonical_url":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/180-degree-phase-shift-when-measuring-s21\/","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"BreadcrumbList","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/180-degree-phase-shift-when-measuring-s21\/#breadcrumblist","itemListElement":[{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum#listItem","position":1,"name":"Home","item":"https:\/\/innovationspace.ansys.com\/forum","nextItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/topics\/#listItem","name":"Topics"}},{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/topics\/#listItem","position":2,"name":"Topics","item":"https:\/\/innovationspace.ansys.com\/forum\/topics\/","nextItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic-tag\/hfss\/#listItem","name":"hfss"},"previousItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum#listItem","name":"Home"}},{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic-tag\/hfss\/#listItem","position":3,"name":"hfss","item":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic-tag\/hfss\/","nextItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/180-degree-phase-shift-when-measuring-s21\/#listItem","name":"180 Degree Phase Shift When Measuring S21"},"previousItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/topics\/#listItem","name":"Topics"}},{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/180-degree-phase-shift-when-measuring-s21\/#listItem","position":4,"name":"180 Degree Phase Shift When Measuring S21","previousItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic-tag\/hfss\/#listItem","name":"hfss"}}]},{"@type":"Organization","@id":"https:\/\/innovationspace.ansys.com\/forum\/#organization","name":"Ansys Learning Forum","description":"Ansys Innovation Space","url":"https:\/\/innovationspace.ansys.com\/forum\/"},{"@type":"WebPage","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/180-degree-phase-shift-when-measuring-s21\/#webpage","url":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/180-degree-phase-shift-when-measuring-s21\/","name":"180 Degree Phase Shift When Measuring S21 | Ansys Learning Forum","description":"Hi,I'm running a parametric sweep by rotating a probe around a central horn antenna. I'm showing a few images below for illustration.Fig 1: At Theta = 0 degrees.Fig 2: At Theta = 10 degreesFig 3: Theta = 20 degrees...And so on...When I measure the phase of the S21 results, I see random 180 degree shifts","inLanguage":"en-US","isPartOf":{"@id":"https:\/\/innovationspace.ansys.com\/forum\/#website"},"breadcrumb":{"@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/180-degree-phase-shift-when-measuring-s21\/#breadcrumblist"},"datePublished":"2024-09-15T02:51:30+00:00","dateModified":"2024-09-15T02:51:30+00:00"},{"@type":"WebSite","@id":"https:\/\/innovationspace.ansys.com\/forum\/#website","url":"https:\/\/innovationspace.ansys.com\/forum\/","name":"Ansys Learning Forum","description":"Ansys Innovation Space","inLanguage":"en-US","publisher":{"@id":"https:\/\/innovationspace.ansys.com\/forum\/#organization"}}]},"og:locale":"en_US","og:site_name":"Ansys Learning Forum | Ansys Innovation Space","og:type":"article","og:title":"180 Degree Phase Shift When Measuring S21 | Ansys Learning Forum","og:description":"Hi,I'm running a parametric sweep by rotating a probe around a central horn antenna. I'm showing a few images below for illustration.Fig 1: At Theta = 0 degrees.Fig 2: At Theta = 10 degreesFig 3: Theta = 20 degrees...And so on...When I measure the phase of the S21 results, I see random 180 degree shifts","og:url":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/180-degree-phase-shift-when-measuring-s21\/","og:image":"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/09\/15-09-2024-1726367016-mceclip0.png","og:image:secure_url":"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/09\/15-09-2024-1726367016-mceclip0.png","article:published_time":"2024-09-15T02:51:30+00:00","article:modified_time":"2024-09-15T02:51:30+00:00","twitter:card":"summary_large_image","twitter:title":"180 Degree Phase Shift When Measuring S21 | Ansys Learning Forum","twitter:description":"Hi,I'm running a parametric sweep by rotating a probe around a central horn antenna. I'm showing a few images below for illustration.Fig 1: At Theta = 0 degrees.Fig 2: At Theta = 10 degreesFig 3: Theta = 20 degrees...And so on...When I measure the phase of the S21 results, I see random 180 degree shifts","twitter:image":"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/09\/15-09-2024-1726367016-mceclip0.png"},"aioseo_meta_data":{"post_id":"382702","title":null,"description":null,"keywords":null,"keyphrases":null,"primary_term":null,"canonical_url":null,"og_title":null,"og_description":null,"og_object_type":"default","og_image_type":"content","og_image_url":null,"og_image_width":null,"og_image_height":null,"og_image_custom_url":null,"og_image_custom_fields":null,"og_video":null,"og_custom_url":null,"og_article_section":null,"og_article_tags":null,"twitter_use_og":true,"twitter_card":"default","twitter_image_type":"default","twitter_image_url":null,"twitter_image_custom_url":null,"twitter_image_custom_fields":null,"twitter_title":null,"twitter_description":null,"schema":{"blockGraphs":[],"customGraphs":[],"default":{"data":{"Article":[],"Course":[],"Dataset":[],"FAQPage":[],"Movie":[],"Person":[],"Product":[],"ProductReview":[],"Car":[],"Recipe":[],"Service":[],"SoftwareApplication":[],"WebPage":[]},"graphName":"","isEnabled":true},"graphs":[]},"schema_type":"default","schema_type_options":null,"pillar_content":false,"robots_default":true,"robots_noindex":false,"robots_noarchive":false,"robots_nosnippet":false,"robots_nofollow":false,"robots_noimageindex":false,"robots_noodp":false,"robots_notranslate":false,"robots_max_snippet":null,"robots_max_videopreview":null,"robots_max_imagepreview":"large","priority":null,"frequency":null,"local_seo":null,"limit_modified_date":false,"created":"2024-10-28 16:29:08","updated":"2024-10-28 16:29:08","ai":null,"breadcrumb_settings":null,"seo_analyzer_scan_date":null},"aioseo_breadcrumb":"<div class=\"aioseo-breadcrumbs\"><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/innovationspace.ansys.com\/forum\" title=\"Home\">Home<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">&raquo;<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/innovationspace.ansys.com\/forum\/topics\/\" title=\"Topics\">Topics<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">&raquo;<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic-tag\/hfss\/\" title=\"hfss\">hfss<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">&raquo;<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\t180 Degree Phase Shift When Measuring S21\n\t\t<\/span><\/div>","aioseo_breadcrumb_json":[{"label":"Home","link":"https:\/\/innovationspace.ansys.com\/forum"},{"label":"Topics","link":"https:\/\/innovationspace.ansys.com\/forum\/topics\/"},{"label":"hfss","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic-tag\/hfss\/"},{"label":"180 Degree Phase Shift When Measuring S21","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/180-degree-phase-shift-when-measuring-s21\/"}],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["449801","39445"],"_bbp_author_ip":["137.122.64.52"],"_btv_view_count":["917"],"_bbp_topic_status":["unanswered"],"_edit_lock":["1726368789:449801"],"_bbp_topic_id":["382702"],"_bbp_forum_id":["27793"],"_bbp_engagement":["39445","449801"],"_bbp_voice_count":["2"],"_bbp_reply_count":["7"],"_bbp_last_reply_id":["388272"],"_bbp_last_active_id":["388272"],"_bbp_last_active_time":["2024-10-05 20:05:30"]},"test":"spate035uottawa-ca"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/382702","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":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/382702\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=382702"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}