There MAY be a hardware solution that could mitigate signal issues.

[chrmjenkins]

http://arstechnica.com/apple/news/2010/06/putting-hard-numbers-to-the-iphone-4-antenna-issue.ars

The discovery that gripping the iPhone 4 in a way that bridges the left and bottom antennas can cause serious signal problems has resulted in—to say the least—a lot of controversy. However, most of the data that either "proves" or "refutes" that existence of said problem has been anecdotal at best.

So AnandTech used a clever hack to get an iPhone 4 to report actual signal strength instead of "bars," giving some quantitative data about how bridging the antennas can negatively affect signal strength. The analysis explains why not all users are affected by the problem, and further investigation also shows that the antenna design does in fact improve reception as long as the left-bottom area isn't bridged when holding the device.

Other mobile handsets definitely have antenna attenuation problems—when cupping an iPhone 3GS or Google Nexus One in the manner that causes problems with the iPhone 4, AnandTech measured 14dBm and 18dBm drops, respectively. However, the problem with the iPhone 4's external antenna is worse; bridging the antennas detunes 3G reception by a full 24dBm.

As long as you have a signal strong enough to show five bars on your iPhone 4—between −51dBm and −91dBm—a 24dBm drop in signal strength won't drop your call or data connection. However, Apple only uses a very small range of signal strength for showing four or less bars, from −91dBm down to the usable signal cutoff of −113dBm. If your iPhone displays four bars or less, a 24dBm attenuation will cut the signal below the useable limit.

That's definitely a significant problem—one that Apple has so far failed to address adequately, in our opinion—but there is good news in all of this. AnandTech also discovered that the iPhone 4 can actually use signal at the lower threshold far more reliably than any previous iPhone. "It's readily apparent that the new baseband hardware is much more sensitive compared to what was in the 3GS," according to Anand Shimpi. "The difference is that reception is massively better on the iPhone 4 in actual use."

Rumors have suggested that Apple has an update to iOS 4 coming soon that may address the issue, and an e-mail from Steve Jobs to a frustrated customer seems to support that theory. A reader indicated to us via e-mail that Apple may be using digitally adjustable solid state capacitors to tune the iPhone 4's antennas, which would make a software fix possible.

While Apple has yet to externally admit there is a problem, the company is definitely looking to beef up its on-staff expertise in antenna engineering—ironically posting job listings for mobile antenna engineers on the same day that the iPhone 4 problems were discovered. Until Apple does offer an official fix (assuming one can be made), using some type of case, or alternately covering the gap between antennas on the bottom left corner with some type of insulating material, is the only reliable solution if you're affected by this problem.

Just don't get your hopes up for a huge improvement.

 

[iphoneguy123]

If Apple could give us just a little ****ing information it would be great.

 

[shawntkeating]

Band-aide

 

[br0adband]

But we already know this...

No offense to the OP, however, or Ars, but it's nothing new, honestly. It doesn't mitigate the fact that you don't touch the antenna, ever, and making a cellular phone with antennas that the user can touch, ever, is a very bad idea, period.

 

[8CoreWhore]

People are reporting that if you remove the sim, wiggle it around, and reinsert it- they get a strong signal and the bars won't drop from a certain grip.

But they aren't considering that the contact is still there and what they've done is ask the phone to reestablish the connection with the tower- or even another tower.

What I'm seeing is the metal contacts of the sim is touching a portion of its tray that has a non conductive coating.

By reinserting the sim, the phone is doing manually what the software is supposed to do regularly- renegotiate a stronger signal or switch towers.

Once you have the strong signal, gripping will not drop bars and signal.

What does this mean? There's a software fix in the works.

 

[Ferris23]

I also said that reseating the SIM renegotiates signal to the strongest available tower hence more bars. I was told that didn't make sense.

 

[chrmjenkins]

People are reporting that if you remove the sim, wiggle it around, and reinsert it- they get a strong signal and the bars won't drop from a certain grip.

But they aren't considering that the contact is still there and what they've done is ask the phone to reestablish the connection with the tower- or even another tower.

What I'm seeing is the metal contacts of the sim is touching a portion of its tray that has a non conductive coating.

By reinserting the sim, the phone is doing manually what the software is supposed to do regularly- renegotiate a stronger signal or switch towers.

Once you have the strong signal, gripping will not drop bars and signal.

What does this mean? There's a software fix in the works.

There could be an issue with some of the SIMs. My launch phone had a SIM that straight-up didn't work. I had to go to AT&T to get a new one.

But we already know this...

No offense to the OP, however, or Ars, but it's nothing new, honestly. It doesn't mitigate the fact that you don't touch the antenna, ever, and making a cellular phone with antennas that the user can touch, ever, is a very bad idea, period.

Old cell phone designs had ones with extendable antennas. Later models had ones with external antennas in the same location that were shorter but still touchable. In fact, some people would hold them and rest their index finger on them during calls.