However, I don't understand why the Smith chart would show 1 + j0 at the 5 Ghz point. Started by avins1234 Replies: 4 RF, Microwave, Antennas and Optics. You can now do this easily with ViVA in IC6.1.4 USR2, IC6.1.5 and later subversions. For S21, the magnitude plot makes sence, because it goes to 0, meaning no energy from port 1 is appearing at port 2. To assess the quality of your s-parameter data, look at the s-parameter data on the Smith Chart. So really what's going on is ADS is plotting the reflection coefficient against lines that aren't shown on the chart, and you're reading the impedance off the lines that are on the chart. 4), which is equivalent to the complex reflection coefficient G for single. That's why this smith chart is the characteristic of your input impedance normalized to (generally) 50 ohm impedance. Then the Smith chart lines would give you the impedance without having to do any tedious calculations. In essence, the Smith chart is a special plot of the complex S-parameter s11 (Ref. If you click on the smith chart, it tells you the impedance at that frequency. In CST you don't need to calculate the input impedance by yourself. I guess you know the relation between S-parameter (reflection coefficient) and input impedance. however, the reflection depends on the input impedance of your antenna. Īnd i don't understand what u want to say, plz tell me in detail. S-parameter shows the ratio of reflected to transmitted power from the input port. In that list you have your smith chart.Īccording to your answer that smith chart is only for S parameters not for input impedence and here i want to plot input impedance of an antenna in CST Microwave studio so plz tell me how can i plot the input impedance on smith chart in CST Microwave studio.Ĭan you tell me what this S-parameter refers to? :D Dont you think it is related to your input impedance? Tell me how can we plot input impedence of an antenna on smith chart in CST Microwave studio.Īfter simulating your structure in CST, take a look at the left column. scattering parameters, noise figure circles, constant gain contours and regions for unconditional stability, including mechanical vibrations analysis.