 Let's talk about the 3D radiation diagrams of antennas, one of the most important antenna characteristics. Hi, I'm Mr. T, the product guy at our velements. If you find our videos useful, consider subscribing to our channel, like or leave a comment. In our previous video, we've explained what an antenna radiation diagram is and how to read it. Most frequently, the data sheets of antennas show the gain of an antenna in the form of a 2D polar plot. We believe that having a 3D radiation diagram is more useful than the 2D version. And in this video, we will explain why. So what is the 3D radiation diagram anyway? Generally, the gain radiation pattern says what is the radiation intensity of the electromagnetic fields an antenna radiates in any direction. A 2D pattern gives this information in a selected two-dimensional cut. Most commonly in two planes perpendicular to each other, you can already guess that the two cuts probably give a limited information compared to the full 3D radiation pattern showing the gain in all three dimensions. Imagine the simplest example of an isotropic antenna. It is a theoretical antenna that radiates with the same intensity in every direction. Let's place it at the origin of the XYZ coordinate system. Drawing radiation intensity in a given direction as vectors and connecting their tips, we get a surface which is the 3D radiation diagram. Since an isotropic antenna radiates with the same strength in all directions, the radiation pattern has the shape of a sphere. It's that simple. The same can be done for any antenna out there. Consider it's placed at the origin of the Cartesian coordinate system. The direction and strength of its radiation at any point in space can be expressed by a vector, with direction and amplitude. Connecting the tips of all the vectors forms a spatial image we call 3D radiation diagram. Since no real antenna is isotropic, let's have a look at a real-life example, a parabolic dish antenna. It focuses the energy of the electromagnetic wave in the direction of its main axis where it's the strongest. Besides that, it also has side-lops that are weaker than the main-hop and are mostly unwanted especially in the unlicensed frequency bands where the interference is the biggest problem. Same thing here as with the isotropic antenna. We can plot the vectors from the origin of the whole spherical surface, but now, because the parabolic dish does not radiate equally everywhere, the vectors will have varying lengths depending on the direction. Connecting the tips of the vectors, we get the 3D radiation pattern of this antenna. The 3D radiation diagram provides a complete information about the gain of an antenna. Since it shows the gain in every possible direction in 3D space, you cannot do better than that. This is why it is generally more useful than the 2D plot, which is obtained from the 3D plot anyway. In some fields, the 2D diagram can be enough, but when examining the side-lopes of an antenna is vital to the particular application. For example, in the wireless internet service provider industry where many operators leverage unlicensed frequency bands, the noise propagated through the side-lopes does a lot of harm. In such cases, it is better to check the 3D radiation pattern and use an antenna with as little side-lopes as possible. Another view on the amount of side-lopes is provided by beam efficiency. Check our previous video if you want to know more about that. The 3D diagram is more difficult to obtain than the 2D one. So historically, the 2D plots became a standard in most engineering fields. But today, with powerful computers available to everyone and advanced antenna measurement setups capable of full 3D measurement, this difference is diminishing. But let's talk about that in another episode. So stay tuned and if you find our videos useful, consider subscribing to our channel, like or leave a comment.