Microwave & mmWave Waveguide Sizes

The use of coaxial cable as a transmission line becomes increasingly detrimental as the operating frequency increases. Microwave and mmWave communication technologies employ waveguide transmission lines between the radio and antenna to overcome the electrical limitations of coaxial cable.

A waveguide is a type of physical structure that directs electromagnetic waves from one point to another. It functions as a conduit for these waves, ensuring they travel in a specific direction without loss of signal strength. Common waveguide shapes include:

• Rectangular: Characterised by a rectangular cross-section, this type of waveguide is widely used due to its simplicity and ease of manufacture. It supports a broad range of frequencies and allows for efficient transmission of electromagnetic waves.
• Circular: This waveguide shape features a circular cross-section. It is typically used in applications where rotational symmetry is required, such as in radar systems. The circular shape allows for the transmission of waves in multiple modes.
• Double Ridge: The double ridge waveguide has two ridges extending along the length of the guide. This design increases the bandwidth of the waveguide, making it suitable for applications that require a wide range of frequencies.
• Elliptical: An elliptical waveguide has an elliptical cross-section. It offers a compromise between the rectangular and circular designs, providing low attenuation and supporting multiple modes.

Each waveguide shape offers unique advantages and is chosen based on the specific requirements of the communication system, such as the frequency range, power handling capacity, and physical constraints.