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Engineering Technology

What are the Potential Challenges of MIMO Antennas?

An awful lot of newly established wireless networks nowadays are highly dependent on MIMO antennas. MIMO stands for Multiple-Input-Multiple-Output. This technology boasts of taking wireless performance of devices to a heightened level of efficiency and reliability. However, much like every other system we have in the modern world, this one has its  own share of weak points. We are going to show you here now some of the most common pitfalls linked to the use and selection of MIMO antennas.

The process of choosing the most appropriate antenna for your application can never be qualified as a trivial undertaking. While system designs are closing in to their full completion, the idea about the use of antenna comes to mind. System designers are always in high anticipation of the gains they need to obtain from the antenna, after which they’d go about and shop around looking for any reasonably priced antenna. They sometimes fall on a whim of looking for an antenna based only on its cool factor or good aesthetics, oblivious of the requirements that it requires.

With regard to the conventional single communications channel, the quarter-wave and half-wave antennas are understood really. The peak current of  standard half-wave antenna is in the middle, while the peak voltage can be found at its end. The center’s peak current is considered very handy due to the antenna’s extremely low impedance and the perfect spot for  antenna feeding using transmission lines of 50 Ohm. We call half-wave antennas dipoles, and we qualify them as plane ground independent.

In a basic quarter-wave antenna, voltage peaks can have a one-quarter wavelength from its feed point. This makes the ground plane dimension to be at least a quarter wave long to allow a properly balanced antenna. Quarter-wave antennas are ground plane dependent and we call them monopoles.

Usually, a half-wave design will not be needing an additional ground plane. Therefore, if you will make an effort to attach that to an access point plastic enclosure, it will not affect its performance. And for this reason, the system designer is likely to witness his expected performance.

If a system designer decided to have a quarter-wave design and have that on the exact, same plastic enclosure, he is up for some surprise that the performance he is anticipating to see is lower than what he is expecting. A simple type of quarter-wave antenna needs to work against a ground plane.

In the case of access point plastic enclosure, there is no metal intended for the quarter-wave. Hence, you can substitute internal components for a ground plane. This may induce the RF current to be possibly seen in any metal that is within its reach, such as the power supply leads.  

If, from the very start, the system designer knew already that a quarter-wave antenna is the best choice for his access, more targeted steps could have been utilized while still in the design stages.

Metalization in the plastic enclosed unit could have been utilized instead. It would provide the plane ground of the antenna electronic shielding. The main circuit board also could be designed to work as the ground plane without the need to create an impact on the other electronics, which is done typically in cellular or mobile phones.

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Engineering

Difference Between Water Jet Cutting and Laser Jet Cutting

Water jet cutting and laser jet cutting are two of the most commonly used material cutting methods in the manufacturing industry. With respect to the material in question and the desired end result, either of these two options would be appropriate for a given application. By delving deeper into the fundamental differences that exist between these two material cutting methods and the range of materials that they usually work well with, we’d be able to determine when and to which project they will best work for.

Laser Cutting 

CO2 is considered as the lifeblood of laser cutting machines, it functions as its energy or fuel. This gas is being transmitted through a beam and under the guidance of custom-built mirrors, then finally directed to your material. In CO2 laser cutting machines, the source of the laser itself can be located inside the machine itself. The beam of the laser can produce an output between 1500 to 2600 watts. When trying to consider the application of laser cutting method in your material cutting requirements, applications, materials as well as precision and safety are among some of the important factors to take into account.  

Materials and Applications 

You can work with laser cutting machines with a manifold of materials. This would include wood, glass, plastic and all kinds of metals with only one exception though, the reflective type. If the material you are going to use as a workpiece is comprised of different materials with different melting points, it might pose a certain level of challenge. Sandwiched structures highlighted by cavities might not be cut by CO2 laser, and any material that eventually proves as having limited access will prove to be difficult to cut also. Cutting material for a 3D project will pose a certain level of a challenge due to the rigid beam guidance.   

Precision and Safety

Precision and accuracy have never been an issue with laser cutting. Depending on the laser speed itself, the minimum cutting slit size can reach to 0.006 inches. Thinner workpieces are at a greater risk of suffering from gas pressure in case that the proper distance is not well maintained. Partial burring is likely to occur due to thermal stress. This will render your cut material to have a striated appearance.  

While safety goggles may not be a constant requirement, the laser cutting process may produce dust and smoke. With some metals and plastics, it may run the risk of even producing toxic fumes, therefore proper ventilation would be critical. Overall, the perceived risks involved when working with a laser cutter is rather low, much like the amount of produced waste and the subsequent cleanup.  

Water Jet Technology

Contrary to how laser cutting machines work, water jet cutters make use of strongly pressurized water to cut through a wide range of materials. To further intensify its cutting power, abrasive particles such as aluminum oxide and garnets can be added to water. Overall, the water jet process is designed to imitate the erosion of the soil in the mountains and nature, just that it is done with much stronger force, greater speed, and higher concentration. 

A high-pressure pump is worked to drive water through tiny and rigid hoses. This action will result in the production of a forceful water jet. Regular water jet cutting machine typically produces about 4-7 kilowatts of output. If the laser source in laser cutters are located inside the cutting machine itself, it works pretty differently for water jets – the pump and the work area are always separate from each other.  

Material and Applications

Water jets are highly reputed in the industry due to its ability to cut through virtually almost any kind of material, even with the combination of materials. But there is one downside to the use of water jet technology and that involves the risk of delamination. 

You can make use of water jet technology with your 3D material cutting projects. But they usually tend to exhibit having a limited ability when it comes to handling sandwich cavities and structures. It is possible to work with materials that give you limited access to it but working your way through it will be very challenging or difficult.  

Precision and Safety

Compared to laser cutting, water jet technology is considered by many experts as not absolutely at par with it. Due to the high amount of force that it requires to have, thin and small parts don’t fare well, and for this reason, they need to be handled with extra care. While thermal stress is not likely to be seen as a possible issue and burring is not likely to appear in the cut, the material surface will have a sand-blasted appearance due to the abrasive material added to the water. This necessitates the use of goggles for eye and face protection. 

Water jet cutting may produce noise. Aside from which may also necessitate a good amount of clean up work to be done in the work area. The addition of abrasive material to the water may likely produce a significant amount of waste.