Nujira provides envelope tracking efficiency results for TD-LTE

In test results, the company said its 20MHz NCT-L1300 ET modulator chip produced twice the energy saving for RF power amplifiers (PAs) operating in TD-LTE mode, compared to other solutions Tim Haynes, pictured, Nujira's ceo, said: "Nujira has consistently produced ET solutions that deliver the highest bandwidths in the industry. We have already demonstrated that our patented High Accuracy Tracking architecture for ET can support 40MHz for LTE-Advanced, and these latest tests show that Nujira continues to lead the way in terms of ET performance." The company says that, for handset OEMs and chipset vendors, TD-LTE presents a significant challenge as handsets can only transmit for a fifth of the time. This means transmit bandwidth and power has to be five times higher than for FD-LTE (frequency division), increasing transmit power by 7dB. This will double the instantaneous current consumed by the RF PA during transmit bursts and Nujira says 50% of the PA energy consumption is at high power/high bandwidth. "Despite being simpler to develop," Haynes continued, "5MHz, or even 10MHz, ET components will not deliver much benefit in a TD-LTE system. Chipset vendors and handset OEMs really need ET solutions that can support the maximum 20MHz bandwidth in order to optimise the RF front end." Nujira's test results and analysis are detailed in a white paper published today and available for download from www.nujira.com/td-lte.