Is the threshold for electromagnetic wave and antenna major getting lower and lower? Is the reliance on simulation software getting higher and higher?
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When I first entered university, I was told that the electromagnetic field major required a high level of math skills, but later I found that except for computational electromagnetics and a few professional courses that required a high level of math skills, all other subjects were solved with simulation software. Even many graduate students around me started with zero foundation and did not even understand the most basic electromagnetic fields, relying entirely on simulation software. Is this a common phenomenon? What should I pay attention to in my later studies?
Let’s take a look at the answers from industry insiders!
1. Development Status and Industry Threshold
Since Hertz proved the existence of electromagnetic waves in 1887, electromagnetic waves have been changing human life. It is certain that electromagnetic waves will still be the most common way to transmit information for a long time in the future. Even if quantum communication becomes popular in the future, it will not shake the important position of electromagnetic waves in communication. Regarding the importance of antennas in the entire communication system, I think it is indispensable, but not crucial. Let me give you a very simple example: rice is indispensable for a meal, and you can't be full without it, but the chicken, duck, fish and meat determine the quality of the meal.
Regarding the threshold of electromagnetic waves and antennas, I think it depends on the level of people. For beginners of electromagnetic waves and antennas, the "threshold" of this profession is getting lower and lower, because a large number of simulation software can solve many problems that originally required a lot of manpower and material resources to solve. But for those who already have some understanding of this profession, the "threshold" of this profession is getting higher and higher. Therefore, for senior electromagnetic antenna experts, the professional threshold has not been lowered. Very profound professional problems cannot be solved by commonly used simulation software, and commonly used software can only solve superficial things. It's like things in the world are always rare and valuable. When everyone can use simulation software to solve an antenna, the design value of this antenna is also reduced. From this perspective, the threshold of electromagnetic waves and antennas is gradually getting higher, because there is no threshold in the field of basic knowledge, and the threshold has been moving towards deeper fields.
2. Basic knowledge and simulation software
Regarding the requirements for mathematical skills in this major, each direction may be slightly different, but it is certain that as long as it is in this industry, the requirements for mathematical skills must be high. Electromagnetic field and microwave technology are divided into several small research directions, and antenna is only one of them. Compared with other directions, the requirements for mathematical skills for antenna should be the lowest, far less than computational electromagnetics. If you cannot understand the equations in the electromagnetic field, you will not have a certain depth of understanding of electromagnetic waves. Antenna theory can be regarded as the sublimation of electromagnetic wave theory. Antenna theory is very important, but most of it is in antenna books, not in basic electromagnetic field and electromagnetic wave books. Sometimes many people may say that they don’t understand any formula in the electromagnetic field, but they can still make antennas. However, if they understand the equations in the electromagnetic field, the efficiency of their antennas will be improved. It is undeniable that you can imitate antennas without understanding the basic principles of electromagnetic waves. In fact, many graduate students are still at this stage, imitating other people’s antenna structures according to other people’s papers, but the antennas imitated in this way generally have the following problems:
(1) There is no solution to the problem with the antenna indicators. Because I don’t understand the principle, the antenna I simulated is just a blind cat catching a dead mouse, and it is often a coincidence. I can’t find which parameters affect which indicators in which form. Therefore, in the process of antenna optimization, I can only scan the parameters continuously, but I can’t solve the problem from the deepest level of the antenna. Many times, I scanned the parameters for several days before I found that the problem was the antenna structure itself.
(2) The antenna cannot be replicated in other frequency bands or with other materials. Each antenna has its own radiation mechanism, and all three-dimensional antennas can be converted into planar antennas in theory. Each antenna can be implemented on different materials. Therefore, if you want to implement the same antenna with different structures and materials, you must understand the basic radiation principle of the antenna, so that the design of the entire antenna can form a complete system in terms of structure and material. Just like the design of an inverted F antenna, only by mastering the basic principles of radiation can you know how to transform a planar inverted F antenna into a three-dimensional inverted F antenna. Only by understanding the principle of the generation of circularly polarized waves can you design different types of circularly polarized antennas without being restricted by antenna type and material.
(3) Antennas cannot be innovated at a deeper level. Many people say that antenna innovation is very simple. Isn’t it just making a slot or digging a hole? From the results, this is indeed the case, but we don’t know where to make the slot, where to dig the hole, why to make the slot, and why to dig the hole. In fact, all these works can be explained from the most primitive theory. For example, when making a slot for a circularly polarized antenna, everyone knows how to make a slot, but how to make it and how big to make it are the key. To understand these things, we must work on the basic principles of the antenna. Moreover, such innovation is only a small innovation, and it is difficult to improve the performance of the antenna to a higher level.
From the current phenomenon, it is an indisputable fact that a large number of designs rely on simulation software, whether it is a master's or doctoral student. In fact, there is nothing wrong with relying on software to design antennas, which can make antenna design more convenient, but the result is the opposite. The main reasons for this situation are as follows.
(1) Software brings a lot of convenience to everyone. Software gives people a sense that it can solve all problems, which leads to people paying less and less attention to theoretical knowledge. People are more willing to accept this simple and quick way, just like everyone knows that walking more is good for health, but they still squeeze into the bus and subway every day.
(2) The research cycle is too short and the utilitarianism is too strong. The whole society's mentality of quick success and instant benefits has also left a deep imprint on scientific research. Students do not have time to learn basic knowledge. Most of the time, they just make some simple improvements to the existing antenna structure and then publish some papers casually, just to meet the graduation requirements as soon as possible, but are unwilling to spend time and energy to study their own fields. No major breakthrough in any field has been achieved in one or two years, let alone in the field of electromagnetic wave antennas, which has been very mature in discipline development. What is more worrying is that students and teachers simply cannot spend one or two years doing only one thing.
(3) The saying that antenna theory is not important has poisoned many students who have just started. This saying was passed down from seniors. Maybe their original intention was not to express this, but it has caused a very bad influence. In fact, this saying may be better explained as follows: We can only analyze the antenna structure qualitatively but not quantitatively. The performance of the antenna cannot be calculated. We can only know qualitatively that if the result is biased, we should go in the direction to eliminate the error.
(4) Current scientific research is mainly project-oriented. This is especially true during the master's degree period. If the project directly requires product transformation, there is basically no need for major innovation. Many things in existing papers are re-implemented, so more often than not, the study of theoretical foundations is neglected. The situation is better during the doctoral stage, which is mainly based on papers and has high requirements for theoretical knowledge.
3. Some advice for beginners
Getting started is very important for any industry, especially for the antenna industry. These technical knowledge that relies heavily on experience will be much more effective if someone guides you, especially for students who want to learn antennas from scratch. So here I want to talk about the detours I took before, so that you can avoid them and better enter the door of antennas.
(1) When you first start learning about antennas, you must learn both simulation software and antenna theory. Many students learn antenna courses very well, but have never simulated a few antennas. If they continue like this, they will never learn the essence of antennas. The key to antennas is how to radiate the energy input to the antenna more smoothly. Therefore, there are two basic points for all antennas: matching and radiation performance, both of which are indispensable. Matching is to ensure that energy can be input to the antenna, which is usually called S11 or impedance bandwidth; radiation performance refers to the antenna's beam width, directivity, and direction of electric field change. Specifically, it refers to whether the energy radiated by the antenna is directed to a very small surface (beam width), the ratio of the power density in the maximum radiation direction to that of an omnidirectional antenna (gain), whether the radiation direction will change (beam scanning), and the direction of the electric field vector change (polarization type). All of these can be clearly displayed on the simulation software. Beginners should simulate the basic antenna structure and match these indicators from the rigid formulas in the book to the vivid images and data in the simulation software.
(2) Beginners should find a senior student who is good at antennas to teach them basic software operation and theory. All beginners will encounter problems. When they encounter problems, they cannot solve them no matter what, and they don’t even know where the problem lies. At this time, senior students who have made the same mistakes are needed to help everyone get out of the misunderstanding. The first thing to solve is the software operation problem. Beginners do exactly the same as in the textbook, but the results are different. 99% of the reasons for this problem are software settings. If you have no experience, it is difficult to find the cause. For this kind of problem, you can ask senior students. It is possible that they can solve the problem that you can’t solve in hours in minutes. This kind of research will not improve your ability in any qualitative way in your lifetime, so there is no need to spend any time on it.
(3) After you have an understanding of several basic antennas, you should simulate the antennas in the paper. When you look at the antennas in the paper, you will find that they are completely different from the basic antenna structures you usually learn. At this time, what you need to do is to simulate according to the paper and not rush to pursue innovation, because innovation at this stage is blind. Before you have a clear understanding of the antenna structure and performance principles, all innovations are blind. After simulating according to the model in the paper, you will naturally understand this type of antenna after a certain number of simulations. For example, various deformations of dipole antennas will not be considered dipole antennas at first. Only when you know the basic principles can you know the meaning of each bend in the structure.
(4) About innovation. Judging from the current development trend of antennas, it is almost impossible to invent new types of antennas, so what needs to be done is to improve the existing antennas. Current innovations can and should be implemented in basic antenna theory. Many times, two seemingly unrelated structures are actually the embodiment of the same basic antenna theory. For example, the cross capacitor, bend, and lumped capacitor on the near-field loop antenna. In essence, they all form phase advance. Innovation from the perspective of how to achieve phase advance will be much simpler. This is the common essence of these structures. Another example is the circularly polarized antenna. The original intention of all designs should be to implement how to make the electric field vector in the far field change in the form of a circle, rather than being restricted to the shape of the antenna itself or whether to use a dipole antenna or a spiral antenna.
(5) Don’t be afraid of making mistakes, think more, and simulate more. In fact, this is true for every industry and every job. You should try more and not be afraid of making mistakes. Simulation is not like making a physical object. Even if you make a mistake, there will not be a big loss. At most, it will cost you some time, and the gain is that you will never make the same mistake again. When you encounter other people’s structures, think more about why, and explain the problem from the bottom of the antenna principle, rather than simply classifying the structure as slotting or digging holes. Different antenna slots and holes often have different effects because they start from different principles. After thinking of the structure, simulate more and verify the possibility. Even if it is a perfect theory, it is unacceptable if it cannot be proven by experiments.
The above is from ai radar sheep - microwave RF enthusiasts answer
As an antenna designer and developer, I feel the need to share my experience. When I was doing my graduate thesis, FEKO was not as popular as it is now. To simulate a simple dipole, I had to write a program myself. Yes, I used Fortran. I had to program the current, self-impedance, mutual impedance, gain pattern, and standing wave ratio by segment. If I made a mistake in one link, I would have to find it for a long time. Anyway, I spent a month to find the bug in a fishbone antenna. Now I can get the result in an hour. It has greatly improved my work efficiency.
Although it is easy to get started, if you don’t have the basic knowledge, you may not understand the basic principles of model setting and may even make low-level mistakes, not to mention optimization and simulation of large arrays.
The above is the answer from the designer of the taro sprout antenna
From the antenna field I have been involved in, I can see that the math requirements are indeed lower. In the past, many simple antennas needed to be calculated manually, and the calculations were not accurate. Now, as long as you understand the basic principles, you can simulate them. However, it is not certain whether the threshold is low or not, because antennas are now more complex and the working environment is also complex.
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