


Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community for help and clear up your study doubts
Discover the best universities in your country according to Docsity users
Free resources
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
standing wave in electronics domain
Typology: Study notes
1 / 4
This page cannot be seen from the preview
Don't miss anything!
Plot the standing wave pattern, V(z) Vs length of the line using MATLAB for given data Z 0 =50 Ω, Z (^) L=0, 25, 50, 75, 100 Ω and attenuation constant α=0, 0.001, 0.002, 0.003,0.004, 0.005, 0.1 .The incident wave amplitude =1 V and operating frequency f=10 GHz also length of the line=2λ. THEORY: Transmission line is a medium through which the EM wave travelling from source to load, so to know the behavior of the EM travelling wave inside the transmission line we have to analysis it but it is very difficult to analysis of an infinitely long transmission line because the parameters are distributed through line so we consider a small section ∆Z from an infinitely long transmission line in figure given below
Now the solution of the travelling wave consist two parts one is forward and reflected shown in the figure Pin is the incident power in the load and P (^) ref is the reflected power from the load. The travelling voltage and current wave can be written as V= V+*exp(-γZ) + V-^ *exp(γZ)
I= I+exp(-γZ) + I -^ exp(γZ) Where V+=Incident voltage wave amplitude V-^ =Reflected voltage wave amplitude I+=Incident current wave amplitude I-^ =Reflected current wave amplitude γ=Propagation constant=α+jβ Now putting the above value- V= V+exp(-(α+jβ)Z) + V-^ exp((α+jβ)Z) V= V+exp(-αZ) exp(-jβZ)+ V^ -^ * exp(αZ)* exp(jβZ) = V+exp(-αZ)[ exp(-jβZ)+ (V-^ / V+)* exp(2αZ)* exp(jβZ)] = V+exp(-αZ)[{cos(βZ)-jsin(βZ)}+Γ{cos(βZ)+jsin(βZ)}] = V+exp(-αZ)[(1+^ Γ)cos(βZ) - j( 1-^ Γ)sin(βZ)] = V+exp(-αZ)(1+ Γ) cos(βZ) [1 – jStan(βZ)] Where Γ= (V-^ / V+) =Reflection coefficient S=(1+ Γ)/(1- Γ)=Standing wave ratio
From the MATLAB simulation we observed the sinusoidal standing wave for different value of load impedance and attenuation constant. If we increase the attenuation constant value by keeping load impedance value constant, than the amplitude of the standing wave decrease simultaneously.