Need comments on my observations on real microstrip series oscillator designs.

时间：04-05 整理：3721RD 点击：

Drain stub electrical length = 180+Angle(s11)/2. Actually it is the same as matching phase in this way: Gs=1/S11
Gate stub electrical length = 180+Angle(s22)/2 - Angle(S21). It is more interesting, it gives me exact stub length matched with the photo of of microstrip oscillator in few papers. While using Gout=S22+(Gs*S12*S21)/(1-S11*Gs) and Gload=1/Gout gived less acurate results.

For example, from push-push oscillator:

Code:

35.8/4Ans = 8.95e0

wavelen=82*4wavelen = 3.28e2
gate_photo=360*94/wavelengate_photo = 1.031707317e2

drain_photo=360*74/wavelendrain_photo = 8.12195122e1

gate_guess=-153/2+180gate_guess = 1.035e2
drain1=-136/2+180drain1 = 1.12e2
drain_guess=drain1-32drain_guess = 8e1

i guessed almost exact stub lengths of 103.5deg and 80deg, while using "bookish" approach we have right value for gate, but wrong guess for drain:

Code:

OpenStub=ATan(-i*50/Zload)OpenStub = 8.917401688e1

of 89deg electrical length for drain, more 10degs.

In another design similar results, bookish drain lenght three times longer than the real drain stub on the photo. But when using 180+Angle(s22)/2 - Angle(S21) for guessing all is precise to 1deg. So where it comes from?

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