Microwave Engineering – Waveguide Components

  Microwaves propagate through microwave circuits, components and devices, which act as a part of Microwave transmission lines, broadly called as Waveguides. A hollow metallic tube of uniform cross-section for transmitting electromagnetic waves by successive reflections from the inner walls of the tube is called as a Waveguide The following figure shows an example of a waveguide.     A waveguide is generally preferred in microwave communications. Waveguide is a special form of transmission line, which is a hollow metal tube. Unlike a transmission line, a 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 and expensive.

 

Advantages of Waveguides

  Following are few 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.
• When microwave energy travels through waveguide, it experiences lower losses than a coaxial cable.

 

Types of Waveguides

  There are five types of waveguides.  

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

  The following figures show the types of waveguides.     The types of waveguides shown above are hollow in the center and made up of copper walls.