Nujira says the first 4G LTE smartphones to use its power efficient RF technology will be on the market next year.
“In the past it was an aspiration to get envelope-tracking (ET) technology designed into volume handsets, now we know it will happen in 2014,” Tim Haynes CEO, Nujira told Electronics Weekly.
“We have worked with chipset vendors for five years to make it happen,” said Haynes.
According to Haynes, 12 chipset vendors have taped-out ET-capable 4G modems with Nujira-compatible interfaces, either OpenET or MIPI.
Haynes also said all the major PA vendors have developed ET-capable power amplifiers (PAs), these are the devices Nujira’s chips will drive.
Based around Nujira’s recently announced NCT-L1200 ET chip, the reference design tackles the multi frequency band challenge of global LTE rollout by covering up to 16 frequency bands from 700MHz to 2.7GHz in a PCB area of less than 200mm2.
According to Haynes, the problem mobile handset makers face is the need to simultaneously support different operating modes (e.g. LTE, TD-LTE, WCDMA, HSPA and GSM) in one handset. But also to support an increasing number of frequency bands.
Nujira applies its envelope-tracking supply modulator to three PAs from three different chip suppliers, covering l6 frequency bands from 700MHz to 2.7GHz.
“Adding envelope-tracking to a couple of specific LTE bands is relatively straightforward, but doesn’t by itself solve the cost, footprint and power consumption challenges the industry is facing,” said Haynes.
“What the mobile industry really needs is multi-mode, multi-band reference designs that can be quickly incorporated into handsets,” said Haynes.
Woodstock
The reference board, dubbed Woodstock, has a multi-mode, multi-band power amplifier, a 2.3-2.7GHz PA and a region- or operator-specific LTE PA.
The Woodstock design integrates Nujira’s NCT-L1200 Envelope Tracking supply modulator with PA devices, antenna switches and filters.
Nujira’s ET modulator enables the handset to deliver full power to the antenna port, maximising coverage and boosting data rates, even for LTE signals with high Peak-to-Average Power Ratios (PAPR), eliminating the need for Maximum Power Reduction (MPR).
The modulator can drive 4 PA devices in parallel even on the highest bandwidth 20MHz LTE channels, with a significant energy saving.
MIPI and OpenET interfaces
Nujira is also supplying a complete suite of MIPI RF Front End (RFFE) control scripts, ET shaping tables, and production calibration algorithms for the solution, minimizing time-to-market for platform vendors and OEMs.
Both the industry-standard MIPI and OpenET interfaces are supported on a growing number of ET-enabled 3G and 4G modem chipsets.
The design supports GSM operation in 850, 900, 1800, and 1900 MHz bands, 3G operation in the 850, 900, 1800, 1900 and 2100 MHz bands, FD-LTE in the 700, 800, 850, 900, 1700, 1800, 1900, 2100 and 2600 bands, and TD-LTE in the 2300, 2600 and 2700 MHz bands.
200 LTE patents
There may be patent issues in the future. Nujira has 200 patents associated with envelop tracking and it knows at least three chip firms, believed to be Qualcomm, TI and RFMD, are developing ET designs.
“We know there are two ways to do envelop-tracking, our patented way and one other less efficient way,” said Haynes.
“We will be looking at these other vendors’ chips very closely with an oscilloscope and a microscope when they come on the market,“ said Haynes.
