{"id":369803,"date":"2024-06-04T15:19:33","date_gmt":"2024-06-04T15:19:33","guid":{"rendered":"\/forum\/forums\/topic\/mirror-impedance-capacitance-between-two-bodies\/"},"modified":"2024-06-04T15:19:33","modified_gmt":"2024-06-04T15:19:33","slug":"mirror-impedance-capacitance-between-two-bodies","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/mirror-impedance-capacitance-between-two-bodies\/","title":{"rendered":"Mirror impedance – capacitance between two bodies"},"content":{"rendered":"

I am trying to obtain the input impedance (reactance) between a mirror and its housing. The mirror is insulated from the housing (which is grounded) by some dielectrics. To simplify, the dielectrics were removed from the model. So I have a body (mirror) and a gap of 1 mm to its housing. Both bodies are  enclosed in a parallelepiped with ???????? = 1, which performs the function of the environment. The “perfect electric conductor” (PEC) boundary conditions was assigned to the exterior walls of this structure. I introduced a port between the housing and body by means of a coaxial.  Electromagnetic RF excitation is applied to the coaxial port located on the reverse side of the mirror. I simulated the model in HFSS for f=80 MHz using a lumped port. Then, I calculated the impedance of the mirror to the housing with the S-parameters: Im(????????) = Im(50(1 + S11\/(1 − S11))), where S11 is the EM voltage wave reflection coefficient and 50 is the characteristic impedance. The result is ~j1 Ω. However, if I calculate the reactance theoretically, it results in ~2.6 Ω. The theoretical value was calculated considering ????=(ε·????)\/???? and <\/span>𝑍<\/span>𝐵<\/span>=<\/span><\/span>𝑋<\/span>𝐶<\/span>=<\/span><\/span>1<\/span>𝑗<\/span>2<\/span>𝜋<\/span>𝑓𝐶<\/span>Z_B=X_C=1\/j2πfC, where A=area=86834.78 mm2 and S=separation=1 mm. ε=1 since the bodies are separated with vacuum. Is this method correct to obtain the reactance\/capacitance between two bodies? <\/p>\n","protected":false},"template":"","class_list":["post-369803","topic","type-topic","status-closed","hentry","topic-tag-capacitance","topic-tag-hfss","topic-tag-Impedancecalculation-1"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["117886","340833"],"_bbp_author_ip":["23.216.133.166"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["174"],"_bbp_topic_status":["unanswered"],"_bbp_topic_id":["369803"],"_bbp_forum_id":["27793"],"_bbp_engagement":["117886"],"_bbp_voice_count":["1"],"_bbp_reply_count":["0"],"_bbp_reply_count_hidden":["1"],"_bbp_last_reply_id":["0"],"_bbp_last_active_id":["369803"],"_bbp_last_active_time":["2024-06-04 15:19:33"]},"test":"gorka-beaskoetxeaidom-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/369803","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\/369803\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=369803"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}