Free Space Wavelength

[gundam]

Hi,

Just check with you guys, apart of from saying that free space wavelength is the wavelength that is found in free space, what is the correct defintion of the free space wavelength and how do we find the value of this? Do I have to use the speed of light=frequency * wavelength to find it?

Thanks a lot

 

[eda4you]

The relationship speed = frequency * wavelength is always valid. The free-space means that the em wave is travelling in a vacuum, that means that εr=1 and µr=1. --> the wave propagates with max. speed --> 3*10^8 m/s.

 

[gundam]

The relationship speed = frequency * wavelength is always valid. The free-space means that the em wave is travelling in a vacuum, that means that εr=1 and µr=1. --> the wave propagates with max. speed --> 3*10^8 m/s.

Hi eda4you,

Which means that if I transmit at 35GHz, using the above equation. my wavelength is ard 8.571mm. Can this be termed as the free space wavelength but restricted to 35GHz only right?

Thanks

 

[eda4you]

The relationship speed = frequency * wavelength is always valid. The free-space means that the em wave is travelling in a vacuum, that means that εr=1 and µr=1. --> the wave propagates with max. speed --> 3*10^8 m/s.

Hi eda4you,

Which means that if I transmit at 35GHz, using the above equation. my wavelength is ard 8.571mm. Can this be termed as the free space wavelength but restricted to 35GHz only right?

Thanks

you are rigth. on a pcb board εr is higher and therefore the propagation speed gets decreased. However, the frequency keeps the same.

 

[masadi]

hello......

i think the constant parameter is frequency, so wavelength depends on where the propagates ( epsilon r)

wavelength_material= wavelength_freespace/sqrt(epsilon_r)

masadi

 

[amicloud]

Free space means the wave propagates in infinite space of pure material space with no boundary,no discontinuity.In this situation the E vector and M vector and k vector are perpendicular to each other.no scatteration will occur.When there is
a boudary ,for example in waveguide systems,because of scatteration,the wave length will be shorter.

 

[evoplus]

hello......

i think the constant parameter is frequency, so wavelength depends on where the propagates ( epsilon r)

wavelength_material= wavelength_freespace/sqrt(epsilon_r)

masadi

Hi,

If that is the case, what would be the wavelength_material be if the wavelength_free space is not known in the first place?