Module 5.4 Generator and Load Mismatches |
| | | | Reflection coefficient of the generator, \(\Gamma_{G}\) = Reflection coefficient of the load, \(\Gamma_{L}\) = Voltage standing wave ratio on the line, \(SWR\) = Input reflection coefficient at the generator, \(\Gamma_{IN}\) = Output reflection coefficient at the load, \(\Gamma_{OUT}\) = | The power delivered to the load \({\rm P}=\frac{1}{2} \left|V_{G} \right|^{2} \frac{R_{IN} }{(R_{IN} +R_{G} )^{2} +(X_{IN} +X_{G} )^{2}}=\) (mW) The power delivered to the input terminal \({\rm P}_{{\rm IN}} =\frac{1}{2} \left|\frac{V_{G} \sqrt{Z_{0} } }{Z_{G} +Z_{0} } \right|^{2} \frac{1-\left|\Gamma _{IN} \right|^{2} }{\left|1-\Gamma _{G} \Gamma _{IN} \right|^{2}}=\) (mW) The power available from the generator \({\rm P}_{{\rm AVS}} =\frac{1}{2} \left|\frac{V_{G} \sqrt{Z_{0} } }{Z_{G} +Z_{0} } \right|^{2} \frac{1}{1-\left|\Gamma _{G} \right|^{2}}=\) (mW) The power available from the network \({\rm P}_{{\rm AVN}} =\frac{1}{2} \left|\frac{V_{G} \sqrt{Z_{0} } }{Z_{G} +Z_{0} } \right|^{2} \frac{\left|1-\Gamma _{OUT} \Gamma _{L} \right|^{2} }{\left|1-\Gamma _{G} \Gamma _{L} \right|^{2} (1-\left|\Gamma _{OUT} \right|^{2} )}=\) (mW) | | |
Introduction: In this module, we discuss the generator and load mismatch effects on the standing wave pattern and power distribution of a lossless transmission line. By adjusting the range sliders, you can observe the dynamic behavior of the standing wave and the variation of the average power delivered to the load.
Ex.1:When the generator and the load impedances are both matched to the line ( \(Z_G = Z_L = Z_0\) ), the maximum power delivered to the load is obtained. Ex.2:When the generator impedance is matched to the line ( \(Z_G = Z_0\) ),, the average power available from the source (PAVS) reaches its maximum. | Parameters: 1. \(V_{G}\) : Generator voltage, (V) 2. \(Z_{G}\) : Generator impedance, (Ω) 3. \(Z_{L}\) : Load impedance, (Ω) 4. \(Z_{0}\) : Characteristic impedance of the transmission line, (Ω) 5. \(\beta\) : Phase constant, (rad/m) 6. \(f\) : Operating frequency, (GHz) 7. \(d\) : Length of the transmission line, (cm) |