Phase Factor in wave propagation (lossy medium): does the distance matters?

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SUMMARY

The discussion centers on the phase factor (BETA) in wave propagation through lossy media, emphasizing its unit of radians per meter. Unlike the attenuation factor (ALFA), which is directly related to distance (d) through the formula 8.69*ALFA*d, the phase factor does not have a straightforward distance relationship in the same context. The phase shift is calculated as BETA multiplied by the distance in the direction of wave propagation, represented as beta(z). The complex propagator in transmission lines is expressed as γ = α + iβ, where α is in nepers per meter and β is in radians per meter.

PREREQUISITES
  • Understanding of electromagnetism theory
  • Familiarity with wave propagation concepts
  • Knowledge of complex numbers in transmission lines
  • Basic grasp of decibel (dB) calculations
NEXT STEPS
  • Research the relationship between phase shift and distance in wave equations
  • Study the derivation of the complex propagator γ = α + iβ
  • Learn about the implications of attenuation in lossy media
  • Explore practical examples of calculating total attenuation in dBs
USEFUL FOR

Electromagnetic engineers, physicists, and students studying wave propagation in lossy media will benefit from this discussion.

Ionito
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In the electromagnetism theory, the phase factor or constant (usually BETA) in wave propagation for lossy medium has the unit rad/m.

I understood that it must be interpreted as the amount of phase shift that occurs as the wave travels one meter.

However, differently of the attenuation factor (usually ALFA), I cannot see examples relating the phase factor to the distance. In other words, we can see the signal attenuation as the form of 8.69*ALFA*d, where d is the distance between the sender and the receiver. However, this distance "d" is not used in conjunction with the phase factor BETA. Is it right?

Can anyone provide me a complete example of the total attenuation (in dBs), given ALFA, BETA, frequency, and distance d, for a plane wave propagating in a lossy medium?

Thanks
 
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Yes, the phase factor appears in the wave equation as beta(phase shift) multiplied with the distance in the direction of wave propagation.i.e if wave is traveling along z direction then phase factor = beta(z)
along with the time dependence wt.

beta is radians per meter,this multiplied with distance gives the phase shift in radians.
 
See the Definitions section of

http://en.wikipedia.org/wiki/Phase_constant#Phase_constant

The propagator in transmission lines is complex; γ = α +iβ. Alpha (α) has dimensions of nepers per meter. Beta (β) has dimensions of radians per meter. The attenuation in dB is 8.686·α·d.

Bob S
 

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