Right at the beginning of this last year, we took a look at WiSpry; they make a MEMS-based tuning product for dynamically adjusting the antenna matching characteristics dynamically as things change. Things like grabbing the phone in the natural (but wrong) place. Not that that would ever happen; I’m sure such phones would always “just work.” But… just in case…
Such capabilities sound great in theory, but WiSpry recently ran an actual test – one that can’t be accused of being a best-case idealized one either. They purchased two phones and literally opened one of them up, replacing the stock tuner with theirs, and then compared the bandwidths between the two phones. The stock phone had 25 MHz bandwidth; the modified phone? 150 MHz.
At issue specifically here is LTE data, which requires a separate diversity antenna in the phone. It’s one of about six antennas (four for cellular, one for GPS, and one for WiFi/Bluetooth). Something there’s not a lot of room for. If the bandwidth for the voice antenna, for instance, can be broadened to make it effective at data as well, then one antenna can be removed.
The lower frequency bands are the most troublesome because they require larger antennas. According to WiSpry, prior to LTE, the total bandwidth range was from 824 to 2170 MHz; their product can extend the lower range down to 700 MHz. LTE’s top end goes to 2700 MHz; their next product will support the entire 700-2700 MHz range.
You can see more on their release…