Question

A mode is a combination of a voltage V and current I, which propagate along z according to the common propagation factor of

• A. \( exp(j\omega t-yz) \) and which, maintains a constant relationship between V and I
• B. \( exp(j\omega t+yz) \) and which, maintains a constant relationship between \( \alpha \) and \( \beta \)
• C. \( exp(j\omega t) \) and which, maintains a constant relationship between \( \alpha \) and \( \beta \)
• D. \( exp(yz + t) \) and which, maintains a constant relationship between V and I

Hint:

A mode is related to propagation of signal along a transmission line and therefore has a relationship with propagation constant which can be represented in terms of \( \alpha \) (attenuation) and \( \beta \) (phase constant).

Answer 1

The Correct Option is A

A mode in a transmission line is a distribution of voltages and currents that propagate along the line with a specific propagation constant. The common propagation factor that defines a mode is of the form \( exp(j\omega t-yz) \), where \( \omega \) is the angular frequency, \( t \) is time and \( \gamma \) is the propagation constant. This mode also maintains a constant ratio between voltage and current.