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How would I approach analyzing the reflection that occurs at a shunt resistor, R1, between two connected coaxial transmission lines with different characteristic impedances? I was initially thinking to use reflection coefficients, but have not found an equation applicable to this particular situation.

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Thanks for any help, it is much appreciated.

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  • \$\begingroup\$ Write the V and I equations for waves on the left line, the right line, and in R1. Note the all three voltages are equal at their junction. Kirchoff allows you to find one current from the other two at their junction. That gives you enough equations for the unknowns. Note that waves arriving at the junction, and leaving the junction, have opposite currents, while their voltages are the same sign. \$\endgroup\$
    – Neil_UK
    Commented Feb 26, 2023 at 17:02
  • \$\begingroup\$ This kind of problem is normally solved with ABCD, or chain matrices. You can look them up in a microwave circuits text. \$\endgroup\$
    – user69795
    Commented Feb 26, 2023 at 19:59

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The reflection coefficient is calculated as usual. The source impedance is Z1 and the load impedance is the parallel combination of R1 and Z2 as the waveform sees the parallel combination of R1 an Z2 when hitting R1.

In your case the reflection coefficient for a waveform hitting R1 from the left is:

formula

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