Is sleeping next to your cell phone bad for sleep?

Do any of you sleep next to your cell phone or smart phone? If so, do you notice any difference in how it affects the quality of your sleep?
I tried sleeping with my phone near me a few nights and also tried sleeping without the phone nearby or turned off, and noticed that when I sleep near my smart phone while it's on, my sleep quality suffers. I get nightmares, feel anxiety and wake up groggy and with a bit of a headache, as though the sleep process was interfered with. But when the phone isn't around or turned off, I slept much better and more normal without interference.
Is there a reason for this? Or is it just a placebo effect?
Have any of you tried both ways and experienced any difference?
What about the wifi in my home? Should I turn it off during sleep too? But even if I do, the neighbors' wifi from multiple houses still runs through the house. What can you do about that? Wear a tin foil hate or radiation protector blanket?
I tried sleeping with my phone near me a few nights and also tried sleeping without the phone nearby or turned off, and noticed that when I sleep near my smart phone while it's on, my sleep quality suffers. I get nightmares, feel anxiety and wake up groggy and with a bit of a headache, as though the sleep process was interfered with. But when the phone isn't around or turned off, I slept much better and more normal without interference.
Is there a reason for this? Or is it just a placebo effect?
Have any of you tried both ways and experienced any difference?
What about the wifi in my home? Should I turn it off during sleep too? But even if I do, the neighbors' wifi from multiple houses still runs through the house. What can you do about that? Wear a tin foil hate or radiation protector blanket?