Can A Phone Case Affect Wifi Reception?

Can A Phone Case Affect Wifi Reception?

We come across this question a lot “Can a Phone Case Affect Wifi Reception?

If you have ever been frustrated with your Wifi Reception on your Cell Phone and you are looking at the causes. You may have asked the question “Can a Phone Case Affect Wifi Reception?”

The short answer is yes, and it also depends on what the Smartphone Case is made of and the proximity of the phone to the Wifi wireless transmitter, modem, router, or wireless network gateway.

Let’s just say if you make an observation that when you have a new phone case on your Smartphone and your reception is not as good as it was. You then remove the phone case and it is better and now you obviously have empirical evidence that the phone case is causing the problem. We have seen many discussions and records of that and the Smartphone manufacturers will also tell you to remove the case if reception is an issue.

Phone Case Signal Loss

Any phone case can cause signal loss if the case design or material somehow blocks the cell phone antenna. Most of the case materials in use today will not absorb or block any substantial amount of Wifi or Cellular signal but some certainly can.

We addressed some of the questions about Cell Phone case materials in previous articles “17 Cell Phone Case Questions Women Ask? and “How To Get Reception On Your Cell Phone In Remote Areas?”

Smartphone Materials

Smartphone Materials Miner

Since many Smartphones today are made out of Aluminum and Stainless Steel Metals, Glass, Plastic, and now Ceramic it is hard to imagine the case having a greater effect on the Cell Phones Signal or Wifi Reception then the phone’s materials themselves. Wireless charging is also having a great effect on the Smartphone frames and case materials with glass fronts and backing as one option.

iPhone Aluminum Case

Metal cases more effectively block radio waves and therefore may degrade your signal quality.

Suggestions by Manufacturers to Remove Your Cell Phone Case Because of Signal Problems.

So let’s start with some of the major Cell Phone Manufacturers.

The first one is interesting because all of these other manufacturers below address this question of Cell Phone interference by a Phone Case but Apple does not anymore? It used to and the link below goes to Apple’s support website but it just says “We’re sorry”.

Apple

“We’re sorry”. We can’t find the page you’re looking for. Please return to the Apple Support homepage.

Samsung

Samsung Support Page for “Phone Has No Mobile Data or a Low Signal “says:

“If your Galaxy phone is experiencing low signal or even no signal at all, you may be unable to connect to the internet, and its ability to make or receive phone calls may be limited.

#5 Remove Accessories.

Remove any third-party accessories, and cases as they can interfere with the antenna, especially anything that claims to boost the signal.”

Huawei

Huawei Support Page “Poor Signal When Using a Metal Protective Case,” says:

“A metal protective case may cause interference to the phone antenna. As a result, the signal quality of the phone deteriorates, which causes call discontinuity, call drop, and slow Internet access speed. You are advised to use a plastic protective case.”

Does Phone Case Affect Reception
Does a Phone Case Affect Reception

One Plus

One Plus Support “No Service or Poor Signal,” says:

“Remove your phone case if there is one, a metal case will block the reception of the signal.

If the issue persists, reinsert the SIM card to check, if the issue still exists, change another available SIM card to check, if you notice the same issue, try to reboot your phone to check.”

Removing the Case to help The Wifi Signal

Remove any type of cover, case or hand blocking the antenna of the smartphone. Using a cover/case on your smartphone gives added protection but at the same time, it may affect the signal reception strength.

Cell Phone / Smartphone Case Materials

Aluminum Metal 
Bamboo / Cork / Wood 
Battery Cases 
Carbon Fiber 
Compostable / Flax Seed 
Fabric 
Faraday EMF Radiation Shields
Metallized Nylon Fleece made of Nylon, copper, nickel, protective coating.
Kevlar – Aramid Fiber 
Leather and Simulated Leather 
Nylon 
Plastic and Rubber Compounds 

  • ABS – Acrylonitrile butadiene styrene
  • PC – Polycarbonate
  • Polyurethane
  • Polypropylene
  • Rubber
  • Silicone
  • TPU – Thermoplastic polyurethane

Scientific Facts:

So being a project manager by trade I don’t believe you can look at a subject like “Can a Phone Case Affect Wifi Reception?” without getting a few basic definitions and facts in order based on the science.

Wifi is Radio Frequency Waves
  • A Wireless Network (Wifi) uses Radio Frequency Waves, just like cell phones, televisions and microwave ovens do.
  • Different materials have different absorption or reflection rates of Radio Frequency Waves.
  • You can receive radio waves in most buildings made of brick, wood, plaster, wallboard, cement, etc..
  • Buildings made of metal or metal-coated glasses, or steel-reinforced concrete, reflect most of the Radio Frequency Waves and you cannot receive radio signals inside of them.
  • It is a scientific fact that different forms of materials cause Radio Frequency Impedance.

Attenuation

“Attenuation is a reduction of signal strength during transmission. It is also a fact that any radio frequency signal will suffer attenuation when it travels from the transmitter to the receiver. A variety of different phenomena give rise to this radio path loss or path attenuation.”

Propagation Losses

Signal propagation and path losses are the key elements of wireless network design. “Radio Frequency Propagation is the way radio waves travel or propagate when they are transmitted from one point to another and affected by the medium in which they travel and in particular the way they propagate or spread out around the Earth in various parts of the atmosphere. Reflection, refraction and diffraction may occur.”

Radio Frequency Attenuation Propagation

Radio Frequency Attenuation Propagation is the attenuation (the reduction of the amplitude of a signal) or (the highest separation of the rate of a radio frequency wave from its average frequency wave rate) wave propagating (the process of causing to multiply or spread out) through a material per measured distance from the source.

Forums – Message Boards – Cell Phone Cases Causing Reception Problems

Forums - Message Boards - Cell Phone Cases Causing Reception Problems

You can of course agree or disagree but since Cell Phone Manufacturers started putting the phone’s antennas internally people have been complaining on Forums and manufacturer’s support pages about the effect of the phone cases on reception.

If you start with low signal reception there are many instances as described in forum after forum from discussions on Apples Communities to Android Authority that shows people have problems with their Smartphone case causing reception interference.

Do cases interfere with iPhone reception? #7

“I had a metal batman case for my phone, link at the bottom if you want to see it. Just after I put it on I started having connection issues. I’d be in an LTE area and go from LTE to 3G to gsrc to Rogers-ext (basically connecting to other networks in a roaming like scenario).”

On top of that, it would take longer to connect calls, the reception was hit or miss too. And battery started going faster too.

Had the case about 3weeks, before taking it off.. I’m sad cause it’s a beautiful case, just not very practical for phone usage.

Phone Case Interferes With Signal.

“I just got my iPhone today. I bought a case from the mall a few weeks ago and it seems that every time I put my phone case on the phone it says no signal.. Lol. When I take it off, it says AT&T LTE again. It only happens when I throw the case on there. It’s the weirdest thing! Has this happened to anyone else??”

Phone Case Affecting Signal

Hi, I’m new to new to the Giffgaff world. My dad and I both have exactly the same phone (sony z3 compact) both on 3G. We’ve noticed that when we’re in the same location my phone will quite often have no signal whereas his will. After some investigation (and lots of turning off phones) we came to the conclusion the phone case I purchased online – a plastic case – was affecting my signal – as soon as I removed the case, the signal was restored to my phone! Would anybody have any idea why this might be (or if it is indeed the phone case!)? Thank you.

The Case for My iPhone Causes It to Loose Reception and WIFI Signal

“Before you take your iPhone to get repaired and spend a whole bunch of money because you think something is wrong with the antenna because you loose signal, check this 1st.

I got a new case for my phone noticed that I would not have cellular reception and WIFI signal at places where my phone was working properly before.. I thought that maybe I had dropped the phone and broke something.. As I hung out in my daughter’s bedroom one day where my signal was at 100% before and now my iPhone was not getting any WIFI signal or cellular reception I decided to take off the case, and magically I had full WIFI bars again.. So I placed the case back on it, and I lost signal again, I took it off was working again.. I did this about 5 times just to make sure it was the case and Indeed it was the plastic case I had on it. So before you take your phone in for repairs take off the case and see if that fixes any signal problems for you. I now only use the hard rubber cases on my phone that do not block the antenna signal.”

Don’t buy a metal phone case

Boy, do I feel stupid.  So I got this nice metal case for my new Galaxy S3 at the dollar store, it was only $2 and made of real metal (not metal-colored plastic crap), and while I know some people might think it’s ugly as hell, I thought it looked pretty sweet!

So I put it on.  And then I get very disappointed when I find out that my new Galaxy S3 can’t receive wifi in my shed like my old Atrix could.  Even my netbook can get my wifi in my shed.  And then I bring the phone inside, and discovered it can’t even get a wifi signal in the basement of my house!  So I walk around, and the wifi is working, just with a very very weak signal.  I thought “this can’t be right, this phone can’t be that crappy”, and then I remembered an experiment I did a while ago, where I wanted to see what material could block a wifi signal.  I remember that all it took was a thin sheet of tin foil on top of a phone or tablet, and the device couldn’t receive wifi at all.

I took my new metal case off my phone.  Suddenly the wifi signal increased by 25dB. Apparently this nice metal case was to blame for all my wifi troubles.

Aluminum Case

“I began using an aluminum case on my iPhone 6 and my cellular reception was notably degraded. I had to return the case because the phone was almost unusable for Maps and other situations where I needed cellular data”

Problems with Smartphones Antennas or Software

Location of Signal

A lot has to do with the area that the cell phone is in and access vicinity to signal which is very important with Wifi reception as it is necessary for most people to be in a building or their home with a router or hub nearby.

Most of the information we have acquired on Cell Phone Case interference is from anecdotal evidence from people reporting it or discussing it on forums and Smartphone manufacturer online support pages, but that being said who knows more than the consumer.

In addition, if there is an actual problem with the antenna or software and when a Cell Phone manufacturer does not want to be blamed for the phones Wifi antenna or performance issues because of the financial implications the following can happen.

Smartphone Manufacturers Continued Signal Reception Issues

In 2010 Apple settled a class-action lawsuit over problems with the iPhone 4’s reception. Owners were paid $15 or a free case to everyone in the United States who bought one of the phones.

From Apple iPhone 4 and iPhone XS Reception to the Samsung Galaxy S10

Apple’s iPhone 4 struggled with an antenna design problem that came to be known as “Antennagate”. When the new iPhone XS and XS Max were released there were reports of connection issues. There were also reports from users who are seeing the same or better signal performance on the new iPhone XS and XS Max.

Large cities or urban areas may not be seeing any connection issues so it is not clear if it is a global issue affecting a small proportion of iPhone users or mainly from rural areas with poor signal. There are also Wi-Fi connectivity issues with 5GHz networks and reports comparing older iPhones with the new models reveal less than half the speed over Wi-Fi.

Samsung

“Galaxy S10+ appears to suffer major LTE signal and connectivity issues on some carriers”

Faraday Cages is another Example of Metal Blocking Signal

Elevators and other rooms with metallic conducting frames and walls simulate a Faraday cage effect, leading to a loss of signal and “dead zones” for users of cellular phones, radios, and other electronic devices that require external electromagnetic signals.

Wifi

Standard Home or Office Wifi Distance

With typical Wi-Fi routers, a good rule of thumb in networking says that operating on the traditional 2.4 GHz band reaches up to 150 feet indoors and 300 feet outdoors.

Long Range Wifi

With a clear line of sight outdoor Wifi point-to-point directional antennas, can be extended from 7 miles or more depending on the system up to the longest unamplified Wi-Fi link is 189 miles or 304 meters.

Additional Causes of Wifi Interference

With every new technology comes problems and WiFi is certainly no exception. The Wifi 802.11 standard was established in 1997 and ever since has been getting better but connectivity with WiFi has been one of the biggest complaints. We use the App WiFi Analyzer to check Wifi Signal on our iPhone and is available from the App Store and is a good free one for Smartphones.

In addition to a Phone Case possibly causing issues, there is also WiFi Interference. Problems associated with WiFi interference can be broken down into areas:

Physical Barriers

The first and most common is Physical barriers such as a wall and the materials that a building is constructed with. Cell signals can be totally or partially blocked and absorbed by materials that conduct electricity. Wifi signal not being unable to reach your device can be impeded and here is a list of common building materials and the level of likely interference they are causing you.

Materials and Signal Attenuation

Material/ObjectSignal Attenuation 
Plasterboard wall3 dB
Glass wall with metal frame6 dB
Cinder block wall4 dB
Office window3 dB
Metal door6 dB
Metal door in brick wall12 dB
Human Body3 dB

Glass / Windows

Wifi signal attenuation means a weakening or reduction in your Wifi signal and is represented in decibels (dB) as seen above. Plain glass or a window is 3 dB comparable with a plasterboard wall but if you put a metal frame on it which is very common it goes 6db. Then add a coating of metal oxide than also can repel signal. You may use your Smartphone near a window thinking it is better. It would make sense that there would be fewer signal impediments through glass than other, denser building materials. Actually mirrors, metallic blinds, and new energy-efficient windows today are extremely effective at blocking a lot of spectrums of light, energy, and as a result signal.

Aluminum Siding, Metal Roofs, Foil Facing Radiant Barrier, and Radiant Insulation 

Manufacturers will tell you these building materials don’t affect Cell and Wifi Signal. But over and over again there are many accounts of homeowners after installing Aluminum Siding, Metal Roofs, Foil Facing Radiant Barrier, and Radiant Insulation on their home saying that the Wifi Signal is just shut off.  “Verizon has made a statement that the radiant shield was like a Faraday shield and that it was blocking the cellular signals.” What is most likely is if your home’s roof and all exterior walls are covered by one of these or a combination of these products then that would be the most likely scenario of creating the “Faraday Cage” effect.

The Weather

Nowadays, the most common use of WiFi is through wireless routers in houses or offices. As a result, such forms of WiFi signals are not affected by adverse weather conditions. But temperature and humidity are two weather conditions that might affect your indoor WiFi signal and with long-range Wifi, rain and wet foliage can decrease range further with extreme amounts of rain.

Tidal Fading

When the line of sight wireless connections across large bodies of water, tidal sounds, sea or stretches of water containing many islands, multipath interference from reflections over water can be considerably destructive.

Electrical Power Lines

Apple states “Avoid using your wireless devices near common sources of interference, such as power cables” Electrical power lines that are in close proximity to your house or in your house can be causing WiFi interference. Try not to set your Wi-Fi router near power lines in the wall or close to the breaker box.

Inadequately Shielded Cables

Electronic devices that you utilize with connector cables that are inadequately shielded can interfere with your wireless devices signal through the leakage. If you are having trouble with your wireless devices and going down the list of troubleshooting this is something you can test by temporarily removing the device from the to see if the signal improves. If that works then replace the cable that connects into the device.

Weak Wifi Reception

Weak Wifi Reception

One of the main causes of interference for Cell Phone users is weak reception. There are a number of causes for poor Wifi reception including router location and the myriad of issues listed in this article. You can improve Wifi signal and strength by moving your router to a more centralized location in your house, change your wireless router channel and reset your router regularly to name a few.

Frequency Interference

Frequency interference is when another signal crosses paths with your signal on a similar bandwidth and corrupts or overpowers it.

Wifi Network Traffic

It’s not uncommon for Wifi signal to be slow or nonexistent when too many people in the same building are competing for bandwidth. In your home alone on the crowded 2.4 MHz bandwidth from microwave ovens, Bluetooth connections, baby monitors, desktops, laptops, tablets, wireless printers video game consoles, smartphones, smart TVs, digital audio players, garage door openers, cars, and car alarms all use the same access.

Adjacent WiFi Network

Powerful WiFi networks, especially those seen in large metropolitan company buildings near your Wifi system can affect your signal and performance.

Cell Phones

Cell Phones themselves can often be a source of interference. Cell Phones and Smartphones transmit signals that can sometimes be overheard by callers nearby and can interfere with your network.

Apps

Apps require bandwidth multiplied by the number of Apps you have on your Smartphone and they can consume a lot of bandwidth. If you leave your Apps running or they are running in the background by design they are also consuming large amounts of bandwidth and signal that will affect your Wifi signal performance.

Bluetooth

Bluetooth devices can also cause interference for their user if the device is on a noisy or weak channel. Bluetooth has since introduced devices that combat this problem, but older models of the headset may still encounter interference.

Satellite Dishes

If a satellite has been wired up incorrectly or the wiring is old and deteriorating, it is possible for them to leak signal interference into the vicinity.

The Importance of the Smartphones Antenna Modules to the Cell Phone Case

In the “Olden Days” the Cell Phones antennas used to stick out above the phone. This wasn’t a huge problem but depending on the type of antenna as some were telescoping it would break or get caught or hang up on your clothes, pocket, or other things.

The antenna was not enclosed inside the Cell Phone so the case didn’t block reception and was not such an issue. But in all fairness, the technology was ancient compared to today’s antennas.

TechInsights’ Teardown and iFixit’s Teardown of the iPhone XS shows that now your new Smartphone Radio Frequency Circuit Board has a multitude of components. Baseband Processor, a Radio Frequency Transceiver Module, and a set of Microstrip Patch Wifi 4×4 MIMO Duplexer Modules to name just a few. So what are those compared to the Cell Phones “Olden Days” Antennas?

iPhone XS Radio Frequency Board Components List

WiFi/Bluetooth SoC 
Baseband Processor/Modems 
32 bit MCU with ARM 
NFC Controller 
Wireless Charging Module 
High/Mid Band Power Amplifier Duplexer (PAD) 
4×4 MIMO Duplexer 
Power Amplification Modules 
RF Transceiver 
RF Switch 
GPS Low-Noise Amplifiers 
Power Management IC

Baseband Processor

A baseband processor is a chip or part of a chip in your Smartphone that manages all the RF or Radio Frequency functions that require an antenna.

(RF) Radio Frequency Transceiver Module

(RF) Radio Frequency Transceiver Module is a microstrip made up of Radio Frequency mixers, amplifiers, pads and other RF components in your Smartphone.

An RF Transceiver is in use when the wireless communication in your Smartphone has been started a phone call or when you are on the internet for instance. Its main application is to make information in the form of voice/data/video suitable to be transmitted over the wireless network.

The Intel RF Transceiver identified in the iPhone XS says it can achieve Cat 16 downlink and Cat 15 uplink, according to Intel. That is comparing its speed to the connecting cable cord in your home or office computer which is probably Cat 5 or Cat 6 cable. The phones are way faster!!

Wi-Fi/Bluetooth Module

A Wi-Fi/Bluetooth Combination Module short-range modules enable Smartphones to easily integrate advanced Wi-Fi and Bluetooth communications with integrated antennas, software stacks, and simple interfaces in a very small space.

MIMO Antennas – MIMO means multiple-input multiple-output (MIMO).

These Wi-Fi and Bluetooth Modules are ultimately for the Internet of Things (IoT) and the integration into our daily lives.

On the Samsung Galaxy S10 Website, it says “With the Galaxy S10 5G—our first 5G-Ready device—you’ll be able to stream and download movies and share life’s moments HyperFast without Wifi.

Problem with Metallic Enclosures

In just one example a report from The International Society of Automation (ISA) kind of characterizes in their “Report on Stainless Enclosures for Wireless Antenna Necessary” that metallic enclosures are not the best medium for Wifi components or signal because they have a tendency to reflect the signal and cause attenuation or degrading of the signal.

  • For most applications, the choice of a metallic enclosure for Wi-Fi components has proven to be an ineffective one – unless there is an external antenna.
  • External antennas have many downsides including their vulnerability to: environmental elements corrosion, ferrous oxide deterioration, natural ambient interference such as that from the environmental forces.
  • This is why many designers are making the switch to non-metallic materials because they allow for free transmission of electronic signals.

External Antenna on Your Wifi Router

That is why you have an external antenna on your Wifi router. So a metal phone case is not a good idea if your Smartphone has a metal frame and body with an internal antenna as many do today. Then you put a metal phone case on top of that causes signals to reflect off, causing poor Wifi Signal penetration.

One Final Interesting Metal Cell Phone Reception Blocking Test

We took two (2) iPhones, an iPhone 7 and an iPhone XR and put them in wrapped Aluminum Foil and a closed Metal Box and tried calling them to see what would happen. We had Wifi showing on both phones when we did the testing.

Now, of course, this is not a real scientific exhaustive test but what was most shocking to us was the iPhone 7 worked fine and rang each time we tested it at least 5 times each at different times in both enclosures. The iPhone XR did not ring and went straight to voicemail every time.

So in conclusion and as discussed above in this article this all works today in a metal Smartphone chassis with a reinforced glass face and back glass and in many instances can struggle on its own too far from a weak signal. If you put the wrong type of case made of a blocking material it can partially shut down some or all of these components described above.

Wifi and Cellular Signal can also be affected by a cell phone case as we have described and as the Cell Phone manufacturers have attested too.

References:

https://www.electronics-notes.com/articles/antennas-propagation/propagation-overview/radio-signal-path-loss.php

https://isa100wci.org/Documents/PDF/Comparing-Materials-for-Protecting-Wireless-Contro.aspx

https://www.dataloggerinc.com/wp-content/uploads/2016/11/16_Basics_of_signal_attenuation.pdf

https://www.cancer.org/cancer/cancer-causes/radiation-exposure/radiofrequency-radiation.html

https://encyclopedia2.thefreedictionary.com/Radio-frequency+impedance+measurements

http://www.madsci.org/posts/archives/2002-03/1015162213.Eg.r.html

https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Borderless_Networks/Unified_Access/CMX/CMX_RFFund.html

https://classroom.synonym.com/can-cases-mess-up-iphones-signal-7031.html

https://support.apple.com/en-us/HT201542

https://support.apple.com/en-us/HT208747

https://support.apple.com/en-us/HT204051

https://www.samsung.com/us/support/troubleshooting/TSG01001598/

https://consumer.huawei.com/us/support/how-to/newbie-guide/?resourceId=en-us00410735

https://support.oneplus.com/app/answers/detail/a_id/309

https://www.am1.us/wp-content/uploads/Documents/E10589_Propagation_Losses_2_and_5GHz.pdf

https://en.wikipedia.org/wiki/Thermoplastic_polyurethane

https://www.thoughtco.com/who-invented-wifi-1992663

https://en.wikipedia.org/wiki/Long-range_Wi-Fi

https://pdfs.semanticscholar.org/d521/17ac311832ac131ef8301626f97f685565b5.pdf

https://www.techinsights.com/blog/apple-iphone-xs-max-teardown

https://www.ifixit.com/Teardown/iPhone+XS+and+XS+Max+Teardown/113021

https://www.murata.com/en-us/apps/mobile/smartphones

http://www.rfwireless-world.com/Terminology/rf-transceiver.html

https://wireless.murata.com/products/rf-modules-1/wi-fi-bluetooth.html

Forums:

https://forums.macrumors.com/threads/do-cases-interfere-with-iphone-reception.2042166/

https://forums.att.com/t5/Apple/Phone-case-interferes-with-signal/td-p/4756939

https://community.giffgaff.com/t5/Help-Support/Phone-Case-affecting-signal/td-p/15809259

https://www.neowin.net/forum/topic/1180647-psa-dont-buy-a-metal-phone-case/

John Mortensen

I was a project manager and am a technology and science enthusiast who loves to study the latest technology, such as AI, smartphones, headphones, and software.

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