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.

073849 bars 500

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:

074258 signal

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.

Related Forum: iPhone

Popular Stories

apple tv 4k yellow bg feature

When to Expect a New Apple TV to Launch

Tuesday April 9, 2024 8:30 am PDT by
It has been nearly a year and a half since the current Apple TV was released, so the device is becoming due for a hardware upgrade. Below, we recap rumors about the next Apple TV, including potential features and launch timing. The current model is the third-generation Apple TV 4K, announced in October 2022. Key new features compared to the previous model from 2021 include a faster A15...
iPhone 16 Camera Lozenge 2 Colors

iPhone 16 Plus Rumored to Come in These 7 Colors

Wednesday April 10, 2024 3:52 am PDT by
Apple's iPhone 16 Plus may come in seven colors that either build upon the existing five colors in the standard iPhone 15 lineup or recast them in a new finish, based on a new rumor out of China. According to the Weibo-based leaker Fixed focus digital, Apple's upcoming larger 6.7-inch iPhone 16 Plus model will come in the following colors, compared to the colors currently available for the...
iPhone 16 Pro Sizes Feature

Alleged iPhone 16 Battery Details Show Smaller Capacity for One Model

Tuesday April 9, 2024 3:46 am PDT by
Apple's upcoming iPhone 16 lineup will feature bigger battery capacities compared to previous-generation models with the exception of the iPhone 16 Plus, which will have a smaller battery than its predecessor. That's according to the Chinese Weibo-based leaker OvO Baby Sauce OvO, a relatively new source of supply chain leaks with an as-yet unproven track record for accuracy. The iPhone 16 ...
apple silicon feature joeblue

Macs to Get AI-Focused M4 Chips Starting in Late 2024

Thursday April 11, 2024 10:10 am PDT by
Apple will begin updating its Mac lineup with M4 chips in late 2024, according to Bloomberg's Mark Gurman. The M4 chip will be focused on improving performance for artificial intelligence capabilities. Last year, Apple introduced the M3, M3 Pro, and M3 Max chips all at once in October, so it's possible we could see the M4 lineup come during the same time frame. Gurman says that the entire...
M3 iPad Feature 3

Apple Event for New iPads Still Considered 'Unlikely' Following Delays

Tuesday April 9, 2024 6:37 am PDT by
Apple is "unlikely" to hold an event to announce new iPad Pro and iPad Air models, according to sources cited by Taiwanese supply chain publication DigiTimes. Bloomberg's Mark Gurman already said Apple was not planning to hold an event for the new iPads, but he made this claim back in early March, before it was reported that the devices were postponed due to manufacturing delays. With the...
iOS 18 WWDC 24 Feature 2

iOS 18 May Feature All-New 'Safari Browsing Assistant'

Wednesday April 10, 2024 6:11 am PDT by
iOS 18 will apparently feature a new Safari browsing assistant, according to backend code on Apple's servers discovered by Nicolás Álvarez. MacRumors contributor Aaron Perris confirmed that the code exists, but not many details are known at this time. Álvarez said it seems like the browsing assistant will use iCloud Private Relay's infrastructure to send relevant data to Apple in a...