iPhone 4 RF failing?

Lately, I've been noticing HUGE variations in the signal strength on my iPhone 4. It goes from 1 bar to 5 bars and back to 1 bar over a short period of time sitting in the same place. At home too I have been noticing such variations...previously I always had 3 to 4 bars.

Today, I went by the Apple store and my phone had variable signal between 1 bar and 4 bars. An employee there had an iPhone 5 with 4 bars at the same time that mine showed only 1 bar.

Is the phone failing? Or has something been changing with AT&T's network?

It doesn't matter how it is held. Even if I just hold it flat on my palm I can see these huge signal variations.

Are there any tests that can be run on a phone to check the health of the RF?

Thanks CubeHacker!

I did this and I observed signal reports anywhere from -82 to -116 within a few minutes all sitting at the same location in my apartment. If I walk around I see similar variations.

I don't remember seeing this level of variation a few months ago...this is quite recent. When I first got the phone I remember having a signal of 3-4 bars at all times within the apartment. Now it is anywhere from 0-5.

Fortunately I don't make a lot of calls, and when I'm at home, if someone calls on cell phone, I immediately call them using my landline (even if I end up having to pay long distance). However, it is really bothersome when driving or when I'm on the road away from home because it is nearly impossible to have a conversation without breaking up or dropping the call.

Do you know if there is some kind of recalibration that can be done? Would resetting to factory defaults and restoring the phone help with such an issue?