I am building a device that needs to be inside of a microwave oven but somehow needs to communicate with another device outside of the microwave.

How can I reflect microwaves so they don't come into contact with the electronics in the device, while still allowing the device to transmit and receive data?

The frequency of the microwaves in a microwave oven is pretty much the same frequency that is used in Bluetooth. I was thinking the only possible way of doing this is to have an antenna that is small enough that it can slip outside of a microwave oven through the door (but small enough so the door is still able to close properly).

Could I use some material to protect the electronics of the device from microwaves? Is there a way to have this device communicate with another device outside of the microwave oven without the microwaves interfering with it?