Why are coaxial cables useful?

Coaxial cables are used as transmission lines for radio frequency, video and data signals. They have traditionally been used as feed lines to connect radio transmitters and receivers with antennas, internet connections, digital audio and cable television signals.

Why the wave guides are preferred in comparison to transmission lines for transporting EM energy at microwave frequencies?

At microwave frequencies, wave guides are preferred to transmission lines for transporting EM energy because of all following except. Losses in transmission liens are prohibitively large. Waveguides have larger bandwidths and lower signal attenuation. Transmission lines are larger than waveguides.

What are wave guides and how they are different from transmission lines?

A two conductor structure that can support a TEM wave is a transmission line. A one conductor structure that can support a TE wave or a TM wave but not a TEM wave is called as a waveguide….Transmission Lines Vs Waveguides.

Transmission Lines	Waveguides
It has a characteristic impedance	It has wave impedance

What is TM wave?

An electromagnetic wave propagating in a propagation medium, including free space, in such a manner that the magnetic field vector is directed entirely transverse, i.e., perpendicular, to the general forward direction of propagation. Common abbreviation TM wave.

What is the reason why waveguide has low copper loss?

The tangential magnetic field needs to be supported by a surface current on the waveguide wall. This implies that the surface current on the waveguide wall becomes smaller as the frequency increases. The wall loss (or copper loss or eddy current loss) of the waveguide, hence, becomes smaller for higher frequencies.

Why does TEM mode exist in transmission lines?

TEM, also referred to as transmission line mode, is the principal mode of wave propagation and exists only in transmission lines made of two conductors. This mode becomes dominant in wave propagation where the cross-sectional area of the transmission line is small compared to the signal wavelength.

What is difference between coaxial and waveguide?

As waveguide is air filled there will be less loss compare to coaxial line. In waveguide, no power is lost through radiation and even dielectric loss is negligible. Waveguide can handle higher power compared to coaxial cable. While coaxial line is smaller in size and lighter in the weight.

What are the advantages waveguides have compared to coaxial transmission lines?

Compared to the coaxial lines waveguides have significant advantages. The main advantage is that waveguides support propagation with lower loss. The electric and magnetic fields, which are used for the transport of energy, are equal to zero in metal surfaces.