A poll shows that the impedance at the entrance on the patch, by l = lMS = 40 mm; of a Micro strip food line with w = WMS = 1 mm, is Zin = 58 + j54 Ω. 1) Find the impedance of the patch, Zp, when impedance is l= 0 mm. I have done it like this: -First I have found the impedance of the micro strip food line: Zf= 82,6 Ω Zin= 58 + j54 Ω (Which is given) Zp= ? (The impedance we are going to find) ______________________________________________________ Zin = Zf * ((Zp+j*Zf*tanβl)/(Zf+j*Zp*tanβl)) But my problem is know how I find the tanβl??? Because when I have the value of tanβl, I can just isolate ZP from the formula above, and find the impedance of the patch.