Akshat Jiwan Sharma

Electromagnetic wave propagation inside electron sheaths in a capacitive discharge plasma  ABSTRACT While the influence of plasma frequency on the propagation of electromagnetic (EM) waves has been extensively studied, the potential role of Lorentz force in perturbing free electrons in plasma sheath and thereby facilitating transmission of electromagnetic waves as per maxwell laws has received comparatively little attention. An oscillating EM wave at a frequency above the plasma frequency interacts with free electrons in the sheaths leading to generation of conduction currents. The frequency of oscillation of these conduction currents is equal to the applied wave frequency.  Although the primary EM wave propagates only a limited distance due to attenuation and geometric spreading, these free electrons carry the currents through the volume of the plasma making them detectable by probes placed deeper within the plasma body. This mechanism is similar to propagation of EM waves ...

  #wififorall At the ITU -APT foundation of India workshop  I shared my views with the industry leaders on the benefits of using wifi for offloading  traffic from the G networks giving consumers a simpler ,faster,cheaper and more efficient way of connecting to the internet.  While I agreed with the participants that it is important to unlock more frequency bands as the demand for data continues to rise, I emphasized that it is also essential for network engineers to recycle & reuse the frequency bands to increase the data transfer rates within the same frequency range.  Cellular networks typically create sectors that cover large areas using high power signals increasing the chances of interference. Wifi on the other hand uses low powered devices that rely on small cells to create dense connectivity zones all working in same frequency range. And it works. Nearly every home,every office,every shop has wifi. People are happily using it without reporting any dis...

Multi element antennas like LPDA (log periodic dipole antennas) have the advantage that they can work over a wide range of frequencies. An antenna has a fixed length which is calculated experimentally to maximize the radiation. It follows therefore that an antenna designed this way will work on a limited range of frequencies. Or only the one it is designed for. When you combine multiple such elements you increase the range of frequencies that the antenna can handle. Each element maximizes the radiation for a particular frequency. This feature is incredibly useful in cellular technologies, for example, that have to transmit over a set of frequencies. Conversely an LPDA can also function as a receiver for a frequency range. Single LPDA receiving many frequencies. However not all elements can radiate on all frequencies. In these cases the elements that do radiate are called active elements those that don't are passive. Passive elements can act as reflectors, increasing the gain of the...

I’m not the best one to give career advice but I would say spend as little time as possible waiting. After you’ve applied to the positions you should look to get busy on personal projects even if they are not paying the bills. But what are the things you can do at this stage? Let's start from simple things and then branch out a bit If you’re good at antennas the easiest thing that you can probably do at this stage is to study the antennas built by other companies and do a technical review for them. What category does the antenna fit in (directional, omnidirectional, portable, outdoor etc etc)? How easy is the system to set up? What is its efficiency (input power vs range/number of devices)? In what cases can it be used? ETC. Once you tune yourself you’ll discover new parameters of evaluation. This exercise will give you an understanding of the antenna market (their price, target customer etc) as well as increase your practical knowledge of different kinds of antennas in use. Beside...

  No they don’t emit, they reflect and keep on reflecting until the signal reaches the other end. Fiber optics use infrared light to transmit data [1]. This is a form of radiation (heated objects also emit IR). In fact, Infrared radiation is so common in nature that there is an entire branch of study dedicated to it called thermal imaging [2]. Fiber cables are radiation guides. Their purpose is to transmit the data signal (infrared radiation) to as long a distance as possible with minimal loss. This is done with the help of total internal reflection. If fiber optic cable emitted any radiation at any point (except at the receiving end) it would fail its purpose. But even then the radiation is not harmful it would get dissipated just as the radiation from a heated body gets dissipated. [1]https://www.thefoa.org/tech/wavelength.htm [2]https://en.m.wikipedia.org/wiki/Thermography I’d love to hear your thoughts. Please don't hesitate to get in touch with me.  Akshat Jiwan Sharma St...

Beamforming refers to focussing the signals in a particular direction. There are two types of beamforming Reflection based This can be seen in parabolic antennas which reflect the omnidirectional radiation from the source to a point (for example to a satellite in space or a base station on the ground) All antennas are omnidirectional. We add reflecting elements to focus their energy where we want. Parabolic dishes are easiest to find but other antennas like yagi,horn etc also help in beam forming. Basically anything that reflects the signal in a particular direction can create a beam. Beamforming is particularly important in point to point wireless backhauls. In these systems you want the signal to go in as straight a line as possible. Just like they would do if they were travelling in a fiber optic or an ethernet cable. (That is why tower installation people try to find line of sight, so that once the beam is in place it is not obstructed by any other object like a building or a tree....

To start with I don't have much idea about the financial health of telecom companies except for the reports that I have been hearing in the news and the opinions I've been reading on social media. Now it may indeed be true that they are not doing that well or it may be exaggerated, hard to tell. But what I do seem to sense is that the telecom industry is going to move away from being an infrastructure provider and become a service provider. Just providing the internet is no longer going to be enough. [Remember that the license for the spectrums that have already been purchased last for 20 years] Verizon purchased yahoo, JIO has their own suite of entertainment and news services and plans to build data centers, airtel has its bank and dish TV etc etc. You can see examples like this everywhere. A few years back, just around the time when whats app was gaining hold in the market there was a big outcry about application companies "eating the lunch" of infra companies. The...

Terahertz antennas are the hot new research topic. I’m afraid you won’t find many books on the matter just yet. Few articles on the web are written on the topic though from time to time https://www.technologyreview.com/2013/03/05/179586/graphene-antennas-would-enable-terabit-wireless-downloads/ As a rule, the greater the frequency the smaller the wavelength. Smaller the wavelength, the smaller the antenna. Terahertz frequencies are so high that the antennas are nano scale. So while you won’t be able to find much on antennas in particular, nano tech is a well researched topic with plenty of material available. For example here is the page on wikipedia that details 7nm chips used in semiconductors. https://en.wikipedia.org/wiki/7_nanometer It's the same theory, through and through. Nothing changes. [1] Now imagine that you succeed in building a terahertz antenna. What is the next step? How much energy can a nano material capture? You will then find out that what you need is an array ...

  Snapdragon 865 is an integrated mobile platform. That is in addition to the RF modulator it contains many other components like processor, camera and audio. To determine what kind of mobile networks it supports you’ll have to look at the modem that is on the platform. Which is in this case “X55 5G modem” https://www.qualcomm.com/products/snapdragon-x55-5g-modem And while it says 5G in the title here are the actual specs in the cellular technology section Cellular Technology: WCDMA (DB-DC-HSDPA, DC-HSUPA), TD-SCDMA, CDMA 1x, EV-DO, GSM/EDGE LTE Technology: LTE FDD, LTE TDD including CBRS support, LAA, LTE Broadcast 5G Technology: SA, NSA, 5G NR FDD, 5G NR TDD As you can see, not only does it support 4G LTE but it also supports older technologies like GSM and Edge. This is why Snapdragon 465 mobile platform could launch in India and other countries even when there have been no 5G networks in place. With that out of the way a natural question would be how can these modems support mu...

5G does not require a new spectrum but it needs it if multiple protocols have to be supported simultaneously. In wireless communication a frequency acts as a physical communication channel. If a certain protocol uses that frequency it does not mean that no other protocol can use it. For example wifi uses 2.4 GHz but so does bluetooth, microwave oven, and even satellites [1] As you can see the underlying physical channel does not care what kind of communication protocol it enables. However it does put telecom operators on a spot. They are already providing a service on a spectrum. Certain frequencies for edge and gsm. Others for 4G. Now in order to bring 5G they either need to buy license for new spectrum or try to accommodate it in the ones they have already bought. That is why some telecom companies are decommissioning old protocols so that they can reuse the existing frequency for new technology without paying more fees for acquiring more spectrum. So yeah you absolutely don't ne...

 Your observation is correct. Broadband is indeed cheaper than G networks and there are several reasons for this. Fixed line is a necessity. The present deployment of wireless technology is such that all telecom towers are actually just the termination points for fixed line networks (Very expensive and power hungry termination points for that matter). So that any communication standard you look at , 3G, 4G, 5G it all runs on fixed lines. Without those fixed lines the G networks won’t really work. Fixed line components are mostly passive (I’ll explain what that means in a minute). This makes them cheaper over the course of very large distances. Although when it comes to the last mile connectivity, they suddenly become expensive. It's not as easy to install fiber in the cities as it is to lay them in an ocean bed. Still fiber installation is no more expensive than installation of electrical lines or laying down of railway tracks or making roads. And if those things can be done certai...

  A base station is the brain behind a wireless network. It is responsible for creation and management of data transmission lines,authentication, routing,computing. Although it looks much different, a base station is simply a desktop computer packaged in a way that it can be placed outdoors. So that if you can build a gaming pc that can play Metal Gear Solid V on max settings you can build a very powerful base station. Now of course there are some differences. For one instead of a graphics card you would go with a network card. Instead of an ssd you might want to get the latest wifi card. You may ask, is this how the base station for 5G and 4G is created? Yes but they use different wireless chips and the software to control these chips are proprietary.. for now. But inside the components are the same. A motherboard, RAM, processor, peripheral components. Luckily there are alternatives. WiFi that can work on both 2.4 and 5 GHZ bands is quite open. Coupled with the advantage that you...

I’m by no means an expert on the industry but I have a few observations that I would like to share with you. I think the biggest problem being faced by the telecom industry is commoditization of their core service. The way things stand people can’t really tell the difference between the operators. The only thing that makes them choose one over the other is the price. It does not really help that most of the work done by the industry is in the background that people don’t really notice much. Coverage is very important for a network, but a normal consumer does not really care about how many miles of fiber optic cables have been laid down. Or for that matter how many new towers have been set up (unless it is for protesting against the harmful effects of radiation, at which point they become surprisingly observant) Another problem that I see is a lack of technological understanding. In the initial years, the telecom industry was the leader in technology and was directly responsible for man...

Telecommunications is an international industry and many of the companies have a global presence. Although I have no experience working in the sector I follow it closely as a technology enthusiast. Telecom companies, today, operate like land owners. A network provider only cares about the product they can supply to the end user. All of the other things that go into making the network functional are of little concern and can be handled by someone else. They are not directly involved in construction,operation or even management of the networks. In order to run their business most “efficiently” nearly all of the functions are outsourced. Although the logic behind this outsourcing is to reduce the prices as well as the risk it would involve to do everything in house, the effect is the opposite. In my opinion. Spectrum licensing is handled by the government. While I believe that licensing is important, auctions are hurting the industry. But on the flip side without auctions telecom companie...

  Any wireless device has antennas that serve as the communication endpoints. That is the antennas are responsible for transmitting and receiving data. When your phone is in the hotspot mode it acts as a base station. In other words it is in the transmission mode (Tx) for wifi. To be able to receive the signal at the time you're transmitting you need at least two wifi antennas. If your mobile has it you can do it. If it does not then you can't. One of the reasons I think phone and chip designers try to limit the number of antennas is that they consume quite a lot of power. You want to maximize the battery life and minimizing the number of operational antennas is one way to do it. As an OS android which is built on linux kernel has no limitation that prevents any device from transmitting at receiving at the same time. The limiting factor is the hardware.

  Although with fiber optic connectivity you should get better speed and data caps at the same price, let us assume, for the sake of the question, that you don't and try to see what benefits optical fiber can bring you. Fiber optic connectivity will maintain service level standards for decades. The technology is mature and so capable that we don't have machines that can process their highest speeds. Fiber optic cables once installed are not going to go anywhere. Advancements in modulation techniques can be applied on the same cable without replacing them. Unless people are careless with installations (like digging where they are installed) fiber optics are here to stay. Given that fiber optic technology is operational for decades once installed year on year the price of running such a network will decrease. Companies can pass on the savings to the consumers or bring more people online by investing the savings. Because the internet is highly reliant on network effects you'll...

  Wireless networking is one of those things that is easier to do in practice than it is to learn in theory. You will learn more by jumping in right ahead rather than poring through the books. But if you’re an absolute beginner you need to start somewhere. So I’ll give an overview of the practical aspects of wireless networks first and towards the end of my answer I’ll give suggestions from where you can learn the theory. All wireless networks have three basic components Antennas that send out wireless signals A hardware that provides input signal to the antennas which it sends out wirelessly An operating system that controls the hardware, which sends the input signals to antennas, which then sends it out wirelessly. Now if you look at something as basic as a wifi router you’ll note that it has Antennas (either external or on chip) A chip to which those antennas are connected An OS (that is accessible through the web admin panel) that controls the chip So as a start you should try ...

   My answer will be a bit roundabout so apologies in advance. It may seem off topic but it will provide background for the actual question. Also I'm not a material science expert and only have second hand knowledge of both ceramics and LCP. Signal strength is one of the most important qualities to consider when designing an antenna both transmitting and receiving. But it's not the only one. Other factors like Ease of construction, installation and maintenance Environment in which the antenna operates The function it has to perform are just as relevant. It is important to stress on the third point because of something called reciprocity principal of antennas It states that properties governing transmission and reception are the same for an antenna. If the antenna is a good transmitter for a particular situation, it is also a good receiver. If we look only at signal strength then nothing can beat parabolic antennas. They are so powerful that they can communicate with satellites...

OTPs are like tokens that help each user connect to a network in a secure manner. A wireless network can be used in a way that a single password is not shared with multiple users. Each individual has his own password/token to access the network. Usually token based authentication is performed with the help of a captive portal. The user is redirected to a web page to authenticate. Web based authentication can take place over https so that the data transmission is encrypted. This setup is different from the one that we use in our homes, for example, where a single password is shared with the members of the family. Thus it overcomes the limitation of the WPA2 encryption scheme making it secure. [1] As for the limited part there could be multiple reasons. But it is important to remember here that airports are generally not responsible for providing internet/wifi. Most likely they outsource it to some service provider who then works with the management team and at some point in time they co...

  I may not be the best person to give career advice. Usually, unless you are well off economically,you have very limited moves straight out of college. The easiest thing is to apply for a job. In wireless technology this would mean Either with an OEM [ mobile phone manufacturers, radio equipment providers,chip makers etc] Or at an ISP/Mobile network operator Or at tower companies This is a good start. But I've noticed many people and especially students take up job hunting as a full time exercise. It is not. Devote a fixed amount of time looking for the positions you want ,3-4 hours, but after that invest everything into personal projects. Here you have a lot of freedom. You can either spend that time acquiring new skills like learning about software that controls wireless network systems or build products that can be sold, for example base stations and antennas. In India there's a big push towards rural connectivity. Companies like C-DOT are always looking for part time suppo...