There are two ways to verify whether your device should work as a Miracast source.
The first method is mainly useful for Laptops and PCs- simply make certain the device is WiDi compatible
You are looking for a sticker or logo like the one shown below.
You can also refer to the manufacturer's website to see if the specifications of your computer include WiDi.
Note that having WiDi hardware only means that your PC can be made to be a Miracast source, not that it is able to be one. You will still need to make certain that you have the latest software drivers for your wireless chipset. See the section entitled “Troubleshooting drivers for Miracast PC's.”