It appears as though Microsoft is getting ready to expand its Lumia line with the Lumia 640 (RM-1109), yet another affordable handset on the Windows Phone platform. There hasn't been an official announcement yet, but in lieu of that, Brazil's National Telecommunication Agency called Anatel recently approved the device in question.
Details are light, though the approval notice does reveal a few fun tidbits, such as that the Lumia 640 will support HSDPA+, offer Wi-Fi and Bluetooth 4.0 connectivity, and sport dual SIM cards. It will also support digital TV -- a feature that PhoneArena says is pretty popular in Brazil -- and come with a 2500 mAh battery.
The rest is speculative. We have a hunch it will launch with no more than 1GB of RAM -- as we pointed out a couple of months ago, the Windows Phone platform is littered with low memory handsets, some with as little as 512MB of RAM.
It will also be interesting to see what System-on-Chip (SoC) Microsoft runs with. Qualcomm recently confirmed that it would be powering Lumia smartphones in 2015 with its Snapdragon 810 processor, though that's a potent part typically reserved for high-end and flagship devices.
Finally, the timing of the release will likely determine whether the Lumia 640 gets outfitted with Windows 8.1 or Windows 10, the latter of which will run on devices with as little as 512MB of RAM, albeit with some features missing.