What is a waveguide and what are its types?

Generally, if the frequency of a signal or a particular band of signals is high, the bandwidth utilization is high as the signal provides more space for the other signals to get accumulated. But the high-frequency signals can’t travel long distances without getting attenuated. We have studied the transmission lines that help the signals to travel longer distances.

A Waveguide

Microwaves propagate through microwave circuits, components and devices, which act as a part of Microwave transmission lines, broadly called as Waveguides.

Definition

A hollow metallic tube of the uniform cross section for transmitting electromagnetic waves by successive reflections from the inner walls of the tube is called as a Waveguide.

A waveguide is generally preferred in microwave communications. A waveguide is a special form of a transmission line, which is a hollow metal tube. Unlike the transmission line, the waveguide has no center conductor.

The Main Characteristics of A Waveguide Are

• The tube wall provides distributed inductance
• The empty space between the tube walls provide distributed capacitance
• These are bulky, heavy, and expensive

Advantages of Waveguides

• Waveguides are easy to manufacture.
• They can handle very large power (in kilowatts)
• Power loss is very negligible in waveguides
• They offer very low loss ( low value of alpha-attenuation)
• The microwave energy when travels through the waveguide, experiences lower losses than a coaxial cable.

Types of Waveguides

There are five types of waveguides. They are:

• Rectangular waveguide
• Circular waveguide
• Elliptical waveguide
• Single ridged waveguide
• Double ridged waveguide

The above shown are the types of waveguides which are made hollow in the center and made up of copper walls. These have a thin lining of Au or Ag on the inner surface.