What Is Slotted Waveguide Antenna? Definition and Benefits

A waveguide slot array antenna is most commonly used in radars. Radar applications need a slotted waveguide antenna design to ensure high gains and mechanical robustness. This is because radar antennas have a higher power transmission which plane arrays can’t efficiently achieve.

Give this article a read if you want to understand an array waveguide antenna’s basics fully. 

Slotted Waveguide Antenna Explained

Slotted Waveguide Antenna
Waveguide Antenna

A slotted waveguide antenna is an array antenna that uses a waveguide to conduct radio waves. There are slots in that waveguide of the antenna. They are holes designed to appear either rectangular or circular. Usually, these antennas are used in systems of microwave radar.

The shape of them, the driving frequency, and the size of them influence the slotted waveguide antenna radiation pattern.

With half of a wavelength, they are designed to be thin. There is minimal width apparent in the slotted waveguide array antenna design.

Check out this slotted waveguide antenna ppt or PowerPoint presentation for more information. 

History of Waveguide Array Antenna 

Alan Blumlein invented the array antenna in 1938.  He did so to develop a practical antenna for use in television broadcasting via VHF.

During World War II, Canada’s National Research Council and McGill University did radar research together. That is when they patented this antenna.

Slotted Waveguide Antenna Advantages

An array antenna is a product that has quite a few advantages. The pros of these antennas are user-friendliness, power levels, wind load, convert communication, current, ration patterns, adjustability, and flexibility.

Let’s look at how this antenna can give you an advantage if you decide to use it.

Easily Operated

If you are new to using these antennas, you won’t struggle much to operate them. They are pretty user-friendly, and you can operate them efficiently. This is the best thing about these antennas.

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As you widen the slot, it becomes as thick as a thick dipole. The bandwidth is also increased in this way. If the slots had more width, there would be a greater chance of cross-polarization, which isn’t ideal.

Lower Wind Load

This antenna is perfect for you if you need an antenna that can face exposure to the elements. Because of the slotted waveguide array antenna design, you can use it outdoors without hesitation.


You can easily use any kind of technology to automate array antennas. Even cutting out or unmounting it from any surface is super easy. 

You can easily adjust this antenna’s design, size, and shape if you want a different performance. 

Low Current

Unlike a dipole antenna, an array antenna will use less amount of current. This will eventually save you a lot of money.

Higher Power Levels

Use these antennas if you need to use an antenna with higher power levels. This is one of the main reasons why navigation systems, weather radars, and other applications use this antenna.

Secure Communication

Most security systems use array antennas for their communication systems. The reason for this is that this antenna is easy to conceal in metallic objects such as fake ventilation systems.

Ration Patterns

A slotted waveguide antenna radiation pattern can receive or transmit signals in every direction.


When it comes to the size of these antennas, they can be easily adjusted. You can reduce the size and make sure that the aerodynamics improve. This makes them fit for aircraft radar dishes.

Disadvantages of Array Antennas

As most things are imperfect, the waveguide array antenna has some cons. Let’s explore these disadvantages.

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High Levels of Cross-Polarization

There is a high level of cross-polarization in array antennas., which isn’t ideal.

Low Radiation

Despite their numerous advantages, these antennas are limited because they do not have a high radiation efficiency.


It’s also important to point out that they are pretty heavy if you compare array antennas with dipole antennas.

The Concept of a Slotted Waveguide Array Antenna Design

We often watch scenes in movies where people monitor the movement of an aircraft, or someone resolutely observes a space mission from a covert establishment. That is the basic concept of array antennas. 

As I’ve already mentioned, people usually use these antennas in different radar applications. The radar system uses radio waves to measure objects’ velocity, range, or angle. 

We usually use radar to locate spacecraft, guided missiles, motor vehicles, weather formations, aircraft, ships, and terrain.

Radar Systems

Before understanding how an array antenna works, you must learn about radar systems. The radar system uses a transmitter to produce different electromagnetic waves on the radio and another antenna for receiving and transmitting signals. It uses a processor and a receiver to analyze objects’ properties. 

The transmitter of the radar system produces radio waves that reflect off of objects and return to its receiver, providing information on the speed and locations of the objects.

In the case of the widespread parabolic antennas, reflectors are used to transmit and receive signals. However, array antennas don’t use any reflectors.

How Slotted Antenna Emits Data

Through its slots, an array emits data. How they are spaced is essential, which is arranged by contemplating the reception and transmission wavelength. 

A slotted waveguide array antenna design is based on a resonant radiator’s principle. This principle makes them similar to dipole antennas. 

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The real difference between these antennas is that dipole antennas have horizontal and vertical fields, unlike array antennas with rotated polarization.

Applications of Slotted Antennas

Array antennas are helpful in enormous ways for a couple of things. Let’s dive into the applications of an array antenna.

  • Initially, television broadcasting utilized these antennas.
  • The most common use of this antenna is in different radar applications.
  • Microwaves and UHF frequencies make use of array antennas.
  • Broadband applications make the most of pylon or pole antennas, specialized versions of array antennas.
  • Most commonly, radar antennas use these antennas.
  • Sometimes, cellphone stations use these antennas.
Slotted Waveguide Antenna

Others antenna

Final Words

The technology behind array antennas has transformed today’s use of radar systems. You can rely on these antennas for navigation purposes.

Why should you use a slotted waveguide antenna? That’s because it isn’t only a user-friendly antenna but also one that is reliable, flexible, and efficient.

Whatever your demand is, commercial or military applications, you won’t be disappointed if you choose a waveguide array antenna. 

Did reading this article help answer your queries? If not, let us know what we should write about next. 

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