The Magnetron: A Cornerstone in Radar Technology and Microwave Oven Invention

The Birth of the Magnetron

In the early 20th century, the limitations of existing radar technology became apparent. The need for more precise and higher frequency signals was crucial for effective operations. Radar systems of the time were bulky and limited in range and accuracy, relying on longer wavelengths that couldn’t provide detailed information about distant objects.

The breakthrough came in 1940 when British physicists John Randall and Harry Boot developed the cavity magnetron, a device capable of generating microwaves at high power levels. The magnetron operates by using a stream of electrons interacting with a magnetic field to generate microwaves. These microwaves are then emitted through resonant cavities within the magnetron, producing powerful and precise high-frequency signals. This innovation was a game-changer, providing the ability to produce small wavelength signals essential for high-resolution radar systems.

The Magnetron and Radar Technology

The development of the cavity magnetron significantly enhanced radar capabilities. Radar systems equipped with magnetrons could detect aircraft and ships with much greater precision. Before the magnetron, radar systems used lower frequency signals that were less effective at detecting smaller objects and were easily scattered by atmospheric conditions. The high-frequency signals generated by magnetrons allowed for smaller and more sophisticated radar systems, capable of discerning finer details and operating more effectively in various environments.

The success of radar technology accelerated advancements in both military and civilian applications. The ability to detect and track objects with high precision had far-reaching implications, leading to innovations in air traffic control, weather forecasting, and navigation systems. The principles of radar technology, powered by the magnetron, became foundational for many modern technological systems.

Magnetron in Everyday Life: The Microwave Oven

The magnetron also found a revolutionary application in the kitchen. In 1945, Percy Spencer, an engineer at Raytheon, discovered that microwaves generated by a magnetron could cook food quickly and efficiently. This serendipitous discovery led to the development of the first commercial microwave oven, radically changing cooking methods worldwide.

Magnetron in Microwave Oven

The early microwave ovens were large and expensive, but as the technology improved and manufacturing costs decreased, they became more accessible to the general public. Today, almost every household contains a microwave oven, showcasing the magnetron’s versatility and lasting impact.

The Evolution of Radar Technology

The evolution of radar technology did not stop with the initial developments. Advances in digital technology and signal processing have further refined radar capabilities. Modern radar systems utilize sophisticated algorithms and digital signal processing to enhance performance, offering improved accuracy, resolution, and reliability.

These advancements have expanded radar’s applications beyond traditional uses. In civilian aviation, radar ensures the safe and efficient management of air traffic. In meteorology, radar systems track weather patterns, helping predict storms and other severe weather events. In automotive technology, radar systems assist in adaptive cruise control and collision avoidance, contributing to vehicle safety.

Conclusion

The invention of the magnetron was a revolutionary milestone that transformed radar technology and had a profound impact on both military and civilian life. Its role showcased its potential for high-precision detection and tracking, while its adaptation into microwave ovens demonstrated its versatility. As radar technology continues to evolve, the legacy of the magnetron endures, highlighting the ongoing importance of this groundbreaking invention. The magnetron’s journey from pioneering technology to everyday convenience underscores its significance and enduring relevance in the modern world.

Celebrating 120 Years of Radar: Christian Hülsmeyer’s Historic Telemobiloscope Demonstration

The Inspiration Behind Radar

Christian Hülsmeyer, a German inventor, was inspired by a tragic boating accident on the Rhine, where two ships collided in foggy conditions, resulting in several fatalities. This incident spurred Hülsmeyer to develop a solution for preventing such tragedies caused by poor visibility. His quest led to the creation of the “Telemobiloscope,” the first patented device to use radio waves for detecting the presence of distant objects, such as ships.

How the Telemobiloscope Worked

The Telemobiloscope was an ingenious apparatus composed of a large wooden box, a spark-gap transmitter, two simple parabolic antennas, and a crude detector. The transmitter generated radio-frequency electromagnetic waves, and the antennas, positioned on a movable platform, could rotate 360 degrees. When the transmitted signals hit an object and reflected back to the receiver, an electric bell inside the device would ring, indicating the object’s presence. Hülsmeyer also devised a toothed-wheel mechanism called Kompass, allowing the user to determine the direction of the detected object.

The Historic Demonstration

On May 17, 1904, Hülsmeyer publicly demonstrated the Telemobiloscope in the courtyard of the Dom Hotel in Cologne. Using a metal gate as the target, Hülsmeyer proved his device could detect objects even when not directly visible. This demonstration was widely reported, showcasing the practical applications of his invention and earning him significant acclaim.

Breakthrough at the Maritime Conference

Following the success in Cologne, Hülsmeyer presented the Telemobiloscope at a maritime safety conference in Scheveningen, Netherlands. During a tour aboard the ship-tender Columbus in the Rotterdam harbor, his device successfully detected passing vessels, impressing shipping industry leaders and highlighting radar’s potential for preventing maritime collisions.

Challenges and Legacy

Despite the initial excitement, Hülsmeyer faced financial difficulties in further developing and commercializing the Telemobiloscope. He eventually sold the rights to his invention to the Trading Company Z.H. Gumpel in Hannover. Subsequent demonstrations faced technical challenges, and competition from Marconi’s Wireless Telegraph Company hindered widespread adoption of his radar technology.

However, Hülsmeyer’s pioneering work laid the foundation for future developments. In 1953, at a radar conference in Frankfurt, Hülsmeyer and Robert Watson-Watt, a key figure in British radar development, were both honored. Watson-Watt acknowledged Hülsmeyer’s contribution by saying, “I am the father of radar, whereas you are its grandfather.” Today, Christian Hülsmeyer is celebrated for his groundbreaking invention, which has had a lasting impact on navigation and safety technologies.

mecorad expands business in North America

On April 2, 2024, mecorad Inc. was established to serve steel and metals producers in North America. The decision to enter the American and Canadian market was made after exploring the market at the AISTech trade fair for two years. Marc Banaszak, CEO of mecorad Inc., says that it was clear that their US customers deserved them to be fully present in the market. There is huge demand for their solutions in North America, and there is a large potential for growth due to the private and governmental investments into growing digitalization and data analytics in the steel industry in the US and Canada. mecorad’s radar sensor platform 1224 is fully FCC compliant and registered for free use in the United States. It can capture digital information about shapes, geometries, distances, levels and presence of material reliably and highly accurately, even down to single micrometers, at any process step in the harshest conditions.

Utilizing state-of-the-art radar technology and industry 4.0 digitalization, the radar sensor platform 1224 provides solutions for both up and downstream processes in the hot steel and metal industry. In contrast to the typical radar sensor development process, all mecorad products were initially designed to withstand the toughest and most extreme conditions, meeting the industry’s demand for robustness. This includes advanced compensation mechanisms, like temperature adjustments, to prevent any result drift. Alongside the exclusive signal processing, the sensor technology offers both accuracy and precision, down to single micrometers. Additionally, mecorad’s single sensor and multiple sensor fusion solutions not only support the PLC but also allow connection to higher IT levels for instant use in advanced control and AI applications.

About mecorad 

mecorad offers customers in steel and metals production, hot-rolling and beyond, higher quality of products at lower production costs. Our patented radar-based plant digitalization solutions combine unparalleled accuracy with highest reliability and robustness under the toughest industrial conditions. At any process step, from the smelter to the finished product, we measure distances, levels and customer-specific dimensions, detect objects under any conditions, optimize these processes with our applications and connect into systems along the value chain.

mecorad Inc. address:

80 Pine Street, Floor 24
New York, NY 10005
Phone: 646-537-7638                                     
       

MaRSCH – On-line Materialklassifikation mittels Radar in Schlacken

On-line material’s classification for slag with Radar

Duration of the project 01.10.2022 – 30.09.2024
Partners involved mecorad GmbH (Lead Partner)

Technical University Bergakademie Freiberg -Institute of Iron and Steel Technology
 
Institute for Nonferrous Metallurgy an Purest Materials
Funding reference 033RK103A
Objective and content of the project Research and development of a method for online measurement and characterization of the properties of molten-liquid phases of slags as using radar
Funded by German Federal Ministry of Education and Research
Programme managed by  Projektträger Jülich
   

Joint project for the research of slags starts

To answer this question, a new funded research project was set up.
In the project “MaRSCH – On-line material classification by radar in slags”, the TU Bergakademie Freiberg and the startup mecorad are using state-of-the-art radar to detect the composition of different slags and to determine their specifics. In this way, a process is to be developed over the next two years to determine the properties of molten-liquid phases of slags and their individual levels in real time.

TU Bergakademie Freibergs Institute for Iron and Steel Technology and Institute for Non-Ferrous Metallurgy and High-Purity Materials are contributing their expertise to the project. The mecorad GmbH puts in its know-how in radar development and the highly complex field of signal evaluation.

“Surveys on the properties and recycling of metallurgical slags are a current research focus. Using radar sensors for this and their testing directly at our test facilities is an exciting new issue for us.” says Dr Thilo Kreschel from the Institute of Iron and Steel Technology at TU Bergakademie Freiberg. 

Professor Alexandros Charitos from the Institute of Nonferrous Metallurgy and High Purity Materials adds: “Modern sensors are the basis for digitalisation in the metallurgical industry and will contribute to the efficiency of processes. Our partner mecorad will develop this radar technology for sophisticated applications in metallurgy as part of the project. We are happy to be involved and look forward to working together over the next two years.”   

As happy is mecorad, Dr. Marc Banaszak admits: “The expertise of the colleagues here at the TU Bergakademie Freiberg and the opportunity to test the research results with them in the laboratories are a real stroke of luck for us. We hope the joint project will lead the way for automation of the separation of slag phases prior to disposal.”

The project is being funded as part of the “KMU innovativ” programme on behalf and with funds from the German Federal Ministry of Education and Research. PT Jülich Research Center joins the project as the executing organization.

Find more information on the KMU innovative programme on the programme site.

Fundings for improvements in continuous casting processes

Our new development can provide geometrical information of slab casting processes directly from below the mould exit in the cooling zone.
While existing systems only check the dimensional accuracy at the end of the straightening zone, mecorad succeeds in measuring the width of the cast strand at a distance of around four metres below the mould level, while the surface of the red-hot strand is just solidifying.  Accuracy of measured width is well below one millimetre.

Furthermore, the determined data is processed real-time by mecorad´s intelligent software application and can be connected via interfaces into the customers applications. This direct feedback means that the casting process can be far better matched to the tolerances to be maintained. Time-consuming reworking, as well as material- and thus cost-intensive overcasting, are significantly reduced. The measured values generated also allow casting models to be further improved and compared across plants.

The new development was presented for the first time together with Aperam Châtelet Belgium at the European Steel Technology and Application Days 2021 in Stockholm.

Förderlogo

Measurement solutions for hot metals forming

We at mecorad looked at our customers’ specific situation in the up- and downstream processing of hot steel and metal, which is – as you might imagine – extremely challenging.

The following considerations led the way to our choice and might help you with your decision:  

  • What level of accuracy has to be realised?
  • What about prevailing environmental conditions? Is there dust, steam, heat? A vacuum? 
  • Are there any specific characteristics of the object’s material? 

To answer the above issues, one has to take at least a short look at the pros and cons of the measuring principles.

In this article, we limit our comparison to the contactless methods of laser, ultrasound and radar. These three are often chosen and – compared to isotopic solutions, such as X-ray – do not imply hazardous radioactive exposure of the worker and workplace.  

Ultrasound

Ultrasound sensors measure distances by using the time-of-flight principle.

Ultrasound waves are pulses of sound at a frequency between 20 kHz and 1 GHz, higher than humans can hear. Bursts of these waves are emitted in a certain time cycle from a sensor and move in the air at the speed of sound. Hitting an – in our case metallic- object, they are reflected by the object’s surface. These reflected echoes return to the sensor. By measuring the time shift of the reflected echo, the distance covered is determined and displayed to the user.

Ultrasound is very suitable for complex objects, even transparent or highly shining ones within homogeneous material, where there is only low sound absorption.  That is why it is often used for quality control to mark defective structures of the material, inclusions, or impurities within a certain material.

However, moving in a heterogeneous environment, the speed of the waves can be interfered by several conditions, such as instable temperatures or a change in the air composition surrounding the object. 

Metal processing usually is not a clean room. So imagine your rather dusty workspace. Or think about the steam of the cooling water. The ultrasound waves are distracted at the micro water drops in the air, leading to an interruption of the transmission and reflection of the signal. The measurement results are no longer precise. Hot objects, like glowing steel slabs, also cause heat convection in the surrounding air by themselves. These convections again interrupt the ultrasound signal. 

Laser

The word laser is the acronym for light amplification by stimulated emission of radiation. Laser beams consist of electromagnetic waves that move at the speed of light (approx. 300000 km/s).

Today, there is a range of laser use cases with a variety of measurement tasks. Lasers can be used for detection, counting of objects, etc. A well-known example for electro-optical measurement of distances and the derived calculation of speeds is even used by the police for speed control. 

In our industrial context, measurements are based on one of the following principles: triangulation, phase shift or time-of-flight, the last as explained before.

Laser sensors are highly precise under determined conditions and therefore often used for measurement tasks in industrial environments. But they lack, if dust or deposits block the view, so the beam can not be emitted properly. And nobody wants to check or clean the laser sensor every once in a while, right? 

Also, at open flames or glowing objects, measurement with standard red-light-laser supplies incorrect signals. The reason for this is the similar frequency of infrared radiation of the laser and the color spectrum of the glowing surface. The dimensions of the object are not recognized correctly, the laser might measure into the surface. In these cases, blue-light laser with a huge spectral distance might be a solution, but they are rather expensive and not the first choice for other measuring tasks. 

Wet, dusty or smeared surfaces have strongly changing reflective properties, declining measurement accuracy, as well. The distance between a laser sensor and the measuring object is restricted to very little variations to deliver robust signals.  And huge water drops, as one can find in the steel industry´s cinder wash, refract the laser signal. 

Radar

Radar measurement is based on electromagnetic waves. The sensor emittes the high-frequency signal, which also propagates at the speed of light, and calculates the distance to an object by measuring the reflection of the signal from that object.  

Radar measurement captures a spot that can be focussed by lenses or antennas. Comparable to focussing a flashlight on a wall, this spot can be more or less focussed. Because of this, even when obstructions occur in the direct line of sight, the sensor still captures the rolling stock.

Radar waves are insensitive to adverse environmental conditions such as high temperatures or polluted air.  Fog, for example, is much more permeable to radar radiation than to visible laser light. Even under zero-view conditions or while measuring through vapour, water drops, dust, cinder and open flames, the beams are still being controllable at high accuracy. 

Though radar – compared under laboratory conditions – may not be as precise as laser, it is from our point of view, the most suitable solution for measurement of width, thickness and length of hot metal. 

That is why we use it in our innovative IIoT measurement solutions.

A startup story- Product development for the steel industry

The spin-off from Chemnitz University of Technology received start-up funding and start-up support from TUClab and SAXEED in addition to equity financing.

Two years after winning the TUClab award, mecorad founder and managing director Dr. Marc Banaszak met Dr. Joseph Heß, project manager of the TUClab, and Dr. Susanne Schübel, managing director of the start-up network SAXEED, at the TCC Technology Center Chemnitz to speak about current projects and mecorad`s development. Things got hot when Marc Banaszak’s team used the new demonstrator to show that the sensors measure precisely even under extreme heat as it is the case in steel production.

“In mid-2020 we found ourselves in the middle of the corona pandemic and accordingly it was challenging for most of the young companies and start-ups that we work with as part of the TUClab to survive in the market. So it is all the nicer to see how mecorad, which we have promoted and supported, has developed further despite this difficult time,” says Heß.
The order books are now filling up again and the demonstrator presented shows that mecorad is ready to make an important contribution to the digitization of the steel industry. “After the visit, I am very convinced that the company will bring everything that is necessary for this,” adds Hess.

 In 2018, mecorad came up with the idea of ​​helping the operators of steel and hot rolling mills to improve their processes with high-precision measurement solutions and applications based on them. In addition, they wanted to support the companies in networking their production to the end customer. The need was and is there, because both the reduction of CO2 emissions from these energy-intensive industries and digitization are currently among the greatest challenges for the steel and metal industry.

Today – three years later – mecorad can provide high-precision measurement solutions that lead to higher product quality and reduce losses in production value. Funding within the framework of the TUClab of the TU Chemnitz prepared the ground for this success.  “So far, the rolled steel has not been measured at the process points, but after it has cooled down and in some cases by hand. Our in-house developed radar sensors can measure the still hot material to be formed in real time and use calculation algorithms to output the values ​​to be expected after cooling.” says Banaszak. If the data generated in this way deviates too much from the production plan, the plant operator in the rolling mill can take countermeasures directly and precisely and thus reduce scrap, overtime and thus also CO2 emissions. In order to integrate the data obtained in real time into the IT systems requested by the customers, mecorad also offers tailor-made solutions. The company is helping to digitize steel production along the value chain.

At the meeting in the TCC, Banaszak demonstrated the reliability of the sensors developed by mecorad using a burner at the new demonstrator. The construction of the demonstrator was part of an MEP grant with which the European Union and the Free State of Saxony promoted the market launch of their product line “wtl series for rolling lines”. The funds come from the European Regional Development Fund (ERDF) and the budget of the Free State of Saxony decided by the Saxon State Parliament.