{"id":170493,"date":"2023-05-25T07:30:02","date_gmt":"2023-05-25T07:30:02","guid":{"rendered":"\/knowledge\/forums\/topic\/in-hfss-3d-the-default-port-impedance-is-50-ohms-however-the-user-may-want-set-the-port-impedance-to-a-complex-number-like-r-jx-ohms-to-account-for-matching-circuits-at-times-if-reactance-is-set\/"},"modified":"2023-07-31T12:34:25","modified_gmt":"2023-07-31T12:34:25","slug":"in-hfss-3d-the-default-port-impedance-is-50-ohms-however-the-user-may-want-set-the-port-impedance-to-a-complex-number-like-r-jx-ohms-to-account-for-matching-circuits-at-times-if-reactance-is-set","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/in-hfss-3d-the-default-port-impedance-is-50-ohms-however-the-user-may-want-set-the-port-impedance-to-a-complex-number-like-r-jx-ohms-to-account-for-matching-circuits-at-times-if-reactance-is-set\/","title":{"rendered":"In HFSS 3D, the default port impedance is 50 ohms. However, the user may want set the port impedance to a complex number like R-jX ohms to account for matching circuits. At times, if reactance is set in the port settings, it may trigger positive S parameters. In this document we explore how correctly set the port to a non 50-ohm termination and obtain the correct S parameters."},"content":{"rendered":"

To model R-jX ohms for port impedance, the recommended method to modeling complex port impedance is to 1.Divide the port into 3 rectangles; two rectangles for the capacitors and one for the port itself. We use two capacitors instead of one for a balanced feed as shown in the attached PDF. 2.The port and two capacitors are in series. 3.Calculate the capacitance C= 1\/(2*pi*f*X) and where X is the imaginary part of the required port impedance. C1 = C2 = 2C 4.The port should be set to the real part of the required port impedance (R) and be normalized to 50 ohms (network analyzer). <\/p>\n

Attachments:
\n1. How%20to%20Set-up%20a%20non%2050%20Ohm%20Port.pdf<\/a><\/p>\n","protected":false},"template":"","class_list":["post-170493","topic","type-topic","status-publish","hentry","topic-tag-17-2","topic-tag-electromagnetics-electronics","topic-tag-excitations","topic-tag-hfss","topic-tag-other"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_wp_page_template":["default"],"_bbp_last_active_time":["05-25-2023 20:20:01"],"_bbp_forum_id":["153856"],"_bbp_author_ip":["209.182.204.162"],"_btv_view_count":["6793"],"siebel_km_number":["2043111"],"product_version":["17.2"],"km_published_date":["2016-09-06T00:00:00.000Z"],"family":["Electromagnetics & Electronics"],"application_name":["HFSS"]},"test":"solution"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics\/170493","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics\/170493\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/media?parent=170493"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}