There have been numerous reports claiming that the iPhone 4 has reception issues and the signals are dropping when someone holds the device with their hands. Apple had launched the new iPhone4 with a list of features which not even Gizmodo would expect including the Retina Display, Large Antenna on the back which means that the complete back section of the device would work as the antenna and save up the overall space but still there are issues with this.
The problem is that when someone holds the iPhone near the metal antenna then the reception goes to zero displaying no bars even though when the handset is in connectivity zone. There are different tests done by people by holiding it with one finger, one on the glass and one on the metal and comparing results, which finally show that there is some real fault going on and which does not seem to be a hardware issue.
Apple would hopefully fix this issue with the next iOS4 update either in iOS 4.0.1 or iOS 4.1 version and make sure that the reception is not impacted in any way you handle the device. Its predicted that human touch can interfere with the antenna because its outside of the photo and this is a normal issue like the Yellow Spot Display Problem.
I hope that Apple will fix the problem. I belive that antenna gate will be forget soon.