Detailed Analysis of iPhone 4 Signal Strength Dropoff

Anandtech has managed to provide a detailed analysis of the iPhone 4's potential antenna signal issue. Their analysis may shed some light on people's experiences with the iPhone 4 and the drop-off in signal when the device is being held in hand.

The issue has generated a lot of press since the iPhone 4 launch due to a variety of user reports on the issue. Apple has maintained that a certain amount of signal loss is normal when mobile phones are held in hand. In a leaked support note, they have also insisted that the iPhone 4 antenna performance is better than that of the iPhone 3GS. Based on Anandtech's analysis, it appears Apple is correct in this statement, though with some caveats.


First, Anandtech managed to hack together a way for the iPhone 4 to report actual signal strength instead of the usual 5 bar signal strength scale. As has been noted by many, this 5 bar scale can be a poor representation of the actual signal strength. As seen above, nearly 40% of the range of possible signal levels is reported as 5 bars. Because of this broad range, there could be a huge difference in actual signal strength despite the same "5 bars" being displayed.

They then ran several tests comparing the signal degradation from holding the iPhone 4 in hand in various positions:


As it turns out, the iPhone 4 does have a significantly greater drop-off in signal strength in all positions as compared to the iPhone 3GS which preceded it. Perhaps the most notable difference is in the "Holding Naturally" position which could theoretically "bottom out" a 4 bar signal or bring the low-end of the 5 bar signals down to 1 bar. Holding the iPhone 4 tightly, of course, accentuates the problem. All phones do exhibit the same behavior, though the iPhone 4's external antenna presumably exaggerates the effect.

However, Anandtech points out that in their testing they found the iPhone 4 antenna is indeed improved over the 3GS -- adding validity to Apple's previous statements. In their testing, Anandtech found that at very low signal strengths (down to -113), the iPhone 4 would hold onto calls far better than the iPhone 3GS.

It's amazing really to experience the difference in sensitivity the iPhone 4 brings compared to the 3GS, and issues from holding the phone aside, reception is absolutely definitely improved. I felt like I was going places no iPhone had ever gone before. There's no doubt in my mind this iPhone gets the best cellular reception yet, even though measured signal is lower than the 3GS.

All in all, the findings may help to explain some seemingly discrepant statements and observations. While the iPhone 4 is likely to perform better at the same signal level as the iPhone 3GS, the signal of the iPhone 4 may be more greatly reduced by attenuation when being held in the same position. This could explain all but the most extreme issues depicted. In the end, Anandtech also suggests using a case may be best move and that with a bumper case, the iPhone 4 has the same attenuation performance as other other smartphones.

Top Stories

First iPhone 12 Mini Hands-On Video Surfaces [Update: Video Pulled]

Wednesday October 28, 2020 1:21 pm PDT by
Apple's iPhone 12 mini and the iPhone 12 Pro Max aren't set to be available until November 13, but a Romanian YouTuber got his hands on the iPhone 12 mini and showed it off today, offering a size comparison between the iPhone 12 and the 12 mini along with going over some of the device's features. The iPhone 12 mini is identical to the iPhone 12 in design and functionality, but it has a...

Apple References Unreleased 2020 16-Inch MacBook Pro in Boot Camp Update

Monday October 26, 2020 8:42 am PDT by
Last week, Apple released an update for Boot Camp, its utility for running Windows on a Mac. While this update would typically be unremarkable, several of our readers noticed that the release notes reference an unreleased 2020 model of the 16-inch MacBook Pro. While this could easily be a mistake, the 16-inch MacBook Pro is nearly a year old, so it is certainly a worthy candidate for a...

After Mocking Apple, Samsung May Remove Power Adapter From Galaxy S21 Box

Tuesday October 27, 2020 4:29 pm PDT by
Samsung's Galaxy S21, coming in 2021, may not include a power adapter or headphones in the box, according to reports from Korean media sites highlighted by SamMobile. Rumors earlier this year also said that Samsung was considering removing these accessories from future smartphone models, but that didn't stop Samsung from mocking Apple for selling the iPhone 12 models without a power adapter...

Report: Apple Silicon iMac Featuring Desktop Class 'A14T' Chip Coming First Half of 2021

Tuesday October 27, 2020 4:14 am PDT by
The first iMac powered by Apple Silicon is set to arrive in the first half of next year and will feature a desktop class "A14T" chip, according to Chinese-language newspaper The China Times. Codenamed "Mt. Jade," Apple's first custom-made desktop processor will be twinned with its first self-developed GPU, codenamed "Lifuka," both of which are being produced using TSMC's 5-nanometer process, ...

iPhone 12 Ceramic Shield Still 'Scratches at Level 6 With Deeper Grooves at Level 7' in Mohs Hardness Test

Wednesday October 28, 2020 7:10 am PDT by
iPhone 12 and iPhone 12 Pro models feature a new Ceramic Shield front cover that is "tougher than any smartphone glass," according to Apple, but the displays on the devices still have similar scratch resistance as previous iPhones based on a new test. Zack Nelson today shared his much-anticipated iPhone 12 Pro durability test on his YouTube channel JerryRigEverything, and based on the Mohs...

2020 iPad Air vs. iPad Pro: Hands-On Comparison

Tuesday October 27, 2020 3:03 pm PDT by
Apple announced the new 2020 fourth-generation iPad Air in September, but the new tablets just started shipping out to customers last Friday. We picked one up and thought we'd do a hands-on comparison with the iPad Pro, which was last updated in March, because both tablets are about as powerful and share many similarities. Subscribe to the MacRumors YouTube channel for more videos. Design and ...

MagSafe Charger Only Charges at Full 15W Speeds With Apple's 20W Power Adapter [Updated]

Monday October 26, 2020 3:38 pm PDT by
Alongside the iPhone 12 and 12 Pro models, Apple introduced a new MagSafe charger that attaches to the magnetic ring in the back of the devices, providing up to 15W of charging power, which is double the speed of the 7.5W Qi-based wireless charging maximum. Apple does not provide a power adapter with the $39 MagSafe charger, requiring users to supply their own USB-C compatible option. Apple...

Apple Files Mystery 'Personal Computer' With Placeholder 'B2002' Name in Bluetooth Product Database

Tuesday October 27, 2020 12:36 pm PDT by
Last week, a listing appeared in the Bluetooth product database for an Apple product with a placeholder name "B2002" and a model number of "TBD." MacRumors was alerted to the listing by health and fitness tech website MyHealthyApple. The product is filed under the "personal computer" category, which Apple has used for previous Mac and iPad listings in the database, so it is hard to pinpoint...

Apple Releases First macOS Big Sur 11.0.1 Beta to Developers [Update: Public Beta Available]

Wednesday October 28, 2020 10:15 am PDT by
Apple today seeded a new macOS Big Sur 11.0.1 beta to developers for testing purposes, with the new beta replacing the existing macOS Big Sur 11 beta 10 update that was released two weeks ago. The macOS Big Sur beta can be downloaded through the Apple Developer Center and once the appropriate profile is installed, subsequent betas will be available through the Software Update mechanism in...

iPhone 12 Models Might Support Reverse Charging of Future Apple Accessories According to FCC Filing

Tuesday October 27, 2020 6:25 pm PDT by
iPhone 12 models could have an inactive wireless charging feature for accessories, according to an FCC filing discovered by VentureBeat's Jeremy Horwitz. In the filing, Apple said that 2020 iPhones support a wireless charging function that will seemingly be enabled for at least one future Apple accessory:In addition to being able to be charged by a desktop WPT charger (puck), 2020 iPhones...