Recent content by yefj

Hello,I have a PNA which works till 120GHz I use a 1mm to 1.85mm adapter to measure till 67GHz 1.85 SMA. I need to measure a differential lines. At first i got low causality about 50% so i played with the connector screwed unscrewed tried wipe of some spots i saw on the ground pad. Then i saw...

Hello Baluncore, I was told that there are two kinds of differential lines. Neck Down and Loosly Coupled. The difference between them is that Neck down has attenuated SDD21,correct? I tried to recreate this effect its not working. How can I design the ND and LC lines to the the difference in...

Hello , I tried to build a differential line and controll the SDD21 as shown in the photo. SDD21=S21-S41 i tried to increase the absolute s41 but the sdd21 is the difference between two complex and as you can see in the photo. i cant get the sdd21 smaller. Where did i go wrong? Thanks.

Hello,is there a way to model crosstalk using ADs transmission line models shown below? Thanks.

Hello , I have built a script by the method described in the article. it has dut with two fixtures on both side. I have fixture-X_length-fixture and fixture-2X_length-fixture what is the best strategy to extract the sparams of the dut. the optical article is good and it uses only one s2p...

Hello Baluncore,I have am trying to visualise this situation using a simpler case in another article shown below. As you can see in the photo taken from the article the Vb and VF pulses are a result of odd mode and even mode being not in the same velocity . why exactly the pulse shape is because...

Hello Baluncore, this is very intresting ,regarding the NEXT. When we have sudden rise in voltage it couples as sudden rise of voltage on the victim because parasitic capacitance I=CdV/dt and has to keep the same amout of voltage on both ends. Two question: 1.the coupling agression creates...

Hello , I saw this very intresting article atatched regarding cross talk in miander lines. Why in differential lines Fext is acting by pulses but NEXT is by steps. Is there a good alternative explanation to what the article says? Thanks.

Hello Baluncore, could you please draw in general the differential line structure you mean so I could try to simulate this principle ? Thanks. "If the track ran across a PCB past many other signals, then you might identify where the crosstalk was coupled from"

update : Hello , I have simulated two differential lines as shown in the photo and got its step responce for every port as shown in the photo. Chatgpt says below that localised jump in voltage at S31 (victim agressor) can suggest localised area where is happens . Is it true? Thanks...

Hello , I started smaller to test the step responce issue. . I have built a basic through differential line as shown below. The S21 is very good almost 0dB. Step responce means we sent 1V step from port 1 and we expect most of it to reach at port 2 then maybe little peaces will arrive later...

Hello BalunCore ,Could you reccomend me a manual on SDD param loss? simple differential transmission line that I want to understant how the SDD21 straight line getting attenuated? Thanks.

Hello Baluncore,I have made a another good method to find crosstalk position between the lines. on one hand we put the TDR of the victim (step responce IFFT into impedance) on the other hand IFFT of SDD21 pure step responce which basickally says that we put one volt step threw the victim and the...

Hello I found a method as following I am doing step responce from the agressor and see what voltage comes to the victim an after how much time. the problem is that pcb is a complex thing i cannot just do derivative of the phase to find velocity. Is there a general method to find phase velocity...

Hello ,Is the a 3D structure I could simulate in EM solver which I could learn how to analyze its cross talk situation?Thanks.