Advantages of Waveguide | disadvantages of Waveguide

This page covers advantages and disadvantages of Waveguide. It mentions Waveguide advantages or benefits and Waveguide disadvantages or drawbacks. It provides links on various topics on Waveguide types and basics.

What is Waveguide?

Introduction:
The waveguide is used to transfer electromagnetic energy from one end to the other end. The EM waves propagate lengthwise through the waveguide. They are hollow structures constructed from conducting material. Waveguide looks similar to a coaxial line without center conductor. Waveguide is a passive microwave device which functions as High Pass Filter (HPF) for microwave frequencies. It is available in different shapes viz. rectangular, circular and elliptical. The first two types are depicted in the figure below.

waveguide

There are two EM modes supported in a waveguide structure viz. transverse electric (TE mode) and transverse magnetic (TM mode). In TE mode, electric field is perpendicular to the direction of wave propagation. In TM mode, magnetic field is perpendicular to the direction of wave propagation. TEM (Transverse Electric and Magnetic) mode does not exist in a waveguide and it is only possible in two conductor based transmission lines. Refer waveguide basics tutorial>> and Rectangular vs Circular Waveguide>> for more information.

Benefits or advantages of Waveguide

Waveguides have several advantages over coaxial and two wire transmission lines. Following are the benefits or advantages of Waveguide:
➨Waveguide supports EM mode propagation with lower losses.
➨EM fields are confined in the space available within the walls of a waveguide. Hence EM fields are shielded from outside and hence they have good amount of immunity against any RF interference from outside.
➨It has higher power handling capacity.
➨EM waves traveling through it has lower attenuation for given cutoff wavelength.
➨It is easy to install waveguides in a microwave transmission systems due to its simple structure on both the ends.

Drawbacks or disadvantages of Waveguide

Following are the disadvantages of Waveguide:
➨It is not suitable for operations at lower frequencies due to increased dimensions.
➨It is very bulky in size and weight.
➨It is not economical.
➨It (rigid waveguide) is not flexible in nature. For applications requiring flexibility, the flexible waveguide is used.
➨It supports narrow band of operation.
➨TEM mode of propagation is not possible in the waveguide.
➨Polarization of EM wave is fixed in rectangular waveguide while it can be altered in circular waveguide due to minor irregularities of surface walls.