Broadband antennas new trend in test & measurement

“Broadband is the trend in the field of testing and measuring equipment. The measuring time, and therefore the costs, can be substantially reduced thanks to this technology.” These are the words of Leendert de Voogd, product manager at EEMC. FHI spoke with De Voogd and his colleague Hans Zijlstra, director of EEMC and parent company Elincom, about new developments within the test and measurement sector. 

“With broadband you use one antenna for a frequency range. You do not change anything in the physical test setup. Previously you had to set up multiple antennas, but with broadband antennas you only vary the source of the frequency,” De Voogd explains. “Especially if you have to measure multiple objects, it is nice that you can leave the antenna in place and only have to set it to the desired frequency of the device to be measured. This not only saves time, but it also reduces the chance of noise. The reliability of the measurements increases.”

Clean signal

“Broadband is a well-known concept, but the former 'broadband antenna' cannot be compared to the broadband antenna of 2022,” continues De Voogd. “The broadband antenna of the past was in fact a narrowband antenna in which the frequency range was boosted by an amplifier. So you placed an extra piece of electronics in the measuring room that added something to the signal. You don't want this in test chambers, because you want to measure passively as much as possible without any influence. With modern broadband antennas you can approach the frequency range as wide as possible in a passive measurement system, without electronics in the antenna itself, so you can measure really cleanly.”  

Send and receive

Broadband antennas are larger than their narrowband predecessors. “The wavelength is inversely proportional to the frequency, so the lower the frequency, the larger the antenna you need,” Zijlstra explains.

“We have launched a relatively affordable broadband antenna on the market, but the purchase price is higher than for a narrowband antenna. You can quickly calculate these costs if you calculate how much money you will save in the long term. Especially when you consider that broadband antennas can both transmit and receive and are therefore twice as effective. This makes it possible to test pre-compliance at your own location, so that you know in advance whether you meet a standard. This way, if necessary, you can make adjustments before the 'real' testing begins.”

Second trend

A second trend within the test and measurement sector, noted by Zijlstra and De Voogd, is the increased interest in materials that shield electromagnetic fields. “You don't see radio waves and electromagnetic fields, but they are there and surrounding equipment can be sensitive to them,” Zijlstra gets started. “We recently had a marine equipment manufacturer experiencing autopilot failures at several customers. Most of the electronics equipment was over 30 years old, but there was also new telecom equipment present that affected the old equipment. Replacing the equipment was too expensive and complex. We were ultimately able to prevent the malfunctions by wrapping the autopilot and shielding it with electrically conductive textiles. It didn't solve the cause of the problem, because that would require replacing all the electronics in the boat, but it did eliminate the consequence.”

“We know more and more about interference radiation and how you can prevent it,” De Voogd adds. “In the past, you were not allowed to turn on mobile phones in the hospital because of the radiation. Nowadays this is allowed, because medical equipment is shielded. That brings me back to the use of antennas. Thanks to the broadband antenna, I do not have to spend two days testing whether the equipment is sufficiently shielded, but one day is sufficient.”

Shielding fabric

Zijlstra responds to this: “Test and measurement rooms are always very expensive, whether you rent them or build them yourself, because they are completely covered with anechoic material. That is why some companies opt for a test tent. It is made of anechoic fabric consisting of several layers of metallized textile. These are special wires that are dipped in copper or silver and that keep out rays. We also sell this same material to wind turbine manufacturers. They apply it to the blades of the blades so that in the event of a lightning strike, the charge is evenly spread over the blade. This prevents the charge from concentrating on one point and destroying the electronics. The shielding material allows the charge to flow away and the damage is limited.”

Rockets and quantum computers

“As a company, we always look for the extreme ends of the frequency spectrum, because we do not want to be a 13-in-a-dozen provider. We try to pick out the special things,” says Zijlstra. “But it is not always the gigantic test equipment that impresses. Sometimes small products make all the difference. How about electrically conductive sealant (form in place gasket) through which no radiation can pass. This is widely used in the medical and military world, for example in the construction of rockets, quantum computers and medical equipment. We are the only company in the Benelux that offers this certified kit.”

Electrically conductive glue

“Another example is electrically conductive glue with which you can attach two metal materials to each other,” De Voogd adds. “In the past, you could only realize a metal-to-metal connection by welding. Unfortunately, there are fewer and fewer people who master the craft of welding. But that's not the only problem. Because devices are becoming smaller, it is sometimes technically not possible to weld. Glue is the solution for this and also makes it possible to process larger quantities of material in one go.”

“The brand of glue that we sell is the only one in the Benelux that can be used in medical equipment and military products because it has met certain EU standards. It is even permitted in space travel because of the thermal connections that can withstand the extreme temperatures in space,” De Voogd continues. “The outgassing values in the glue must meet strict NASA requirements and of course the glue must not decompose in space. So this is not just a tube of adhesive. There is a lot more to it than you think.”

Very dangerous

According to Zijlstra, testing and measuring rays will only become more important in the future. “The demand for electronics continues to increase, both from consumers and companies, and all those devices and apps influence each other. This can lead to unpleasant and even life-threatening situations. Take for example the solar fields, these are fields with hundreds of solar panels together. So much RF power is released there that it can affect the communications equipment of emergency services, such as the police and fire brigade. These services operate in the same frequency range as the linked ones inverters. If you do not take measures for this, it can have disastrous consequences, while the solution is simple. There are mechanical and electrical filters on the market that reduce the radiation from that solar field inverters keep it inside,” says Zijlstra.

Espionage

Criminals also like to use RF technology. De Voogd: “Your laptop is in fact one big transmitter. If I sit a hundred meters from your house with spy equipment, I can see everything you do on your screen or monitor. This is very undesirable for employees of the police, Defense or the AIVD. Here too the solution is relatively simple. You can attach a special screen to your monitor that blocks the outside radiation. Because the screen is transparent, you can see everything yourself, but people from outside cannot watch. There are very thin metal wires in the screen that the rays do not penetrate,” De Voogd explains. “You can apply the material in two ways: by laminating (applying it to a surface) or by pouring it (casting). The latter is preferable, because material that you laminate can also de-laminate, for example under the influence of cleaning products. Bee cast that is not possible.”

Free gadget

“For real spies, we also supply foil with which you can mask off windows,” De Voogd continues. “You can't pick up anything from the outside, electromagnetically speaking. We even sell electrically conductive wallpaper and clothing.”

EEMC has developed a gadget especially for the WoTS that is made of the same shielding material as the test tents. This is a bag made of sealing, radiation-free material in which you can, for example, store your mobile phone. No one can then read data. Would you also like to receive such a handy and, above all, safe bag? Then visit the EEMC/Elincom stand during the WoTS, from September 27 to 30 in Jaarbeurs Utrecht. You will find the EEMC/Elincom stand in hall 9 at location 9B049. Be quick if you want to get your hands on the gadget, because there are only a hundred free bags available and they're gone.  

EEMC is a subsidiary of Elincom. The Dutch company has existed since 1977 and specializes in test and measurement products and services. EEMC is ISO 9001 certified by BVQI. For more information, please refer to the website: https://www.eemc.nl/.