本論文研究以傳輸線及電路模型為架構之時域模擬器,來獲得待測系統之 S 參數(S parameters). 測試區段之連接埠以傳輸線等效模型連接, 主測試埠以一時域脈衝進行輸入, 並於其它連接埠傳輸線之末端匹配以等值之阻抗. 藉由模擬器之運算可以取得主測試埠之反射波型與其它各連接埠之穿透波型模擬值. 利用傅立葉轉換將各波型之模擬值由時域轉換至頻域可得到測試區段之頻率響應. 藉由此方法可以得到該測試區段之S 參數; 包含反射係數與穿透係數. 在此論文的後續章節中, 一些雙埠(two-port), 三埠(three-port )及四埠(four-port )的電路被用來驗證此方法之有效性與準確性. This thesis presents a time-domain numerical simulator of using transmission line and equivalent-circuit model to obtain scattering parameters of the test section. The ports of the test section are connected with transmission lines. A time-domain pulse is given into the input port for extracting the properties of the system with a matched load added at the terminal of each transmission line. With this simulator, the incident and reflected waveforms at the input port, and transmitted wave at the other ports can be achieved. A Fourier-transform approach is applied to transfer the input, reflected, and transmitted waveforms from the time domain into frequency domain to obtain the frequency responses. The S parameters and the characteristics of the system including reflection and transmission coefficients can be obtained. Examples of two-port, three-port, and four-port networks are investigated in this thesis to confirm the feasibility. The results obtained from the simulator are compared with results from some alternative approaches such as AC-analysis method and show precise accuracy of this methodology.
