Leuven, Belgium – Feb. 22, 2016 – World-leading nanoelectronics research center imec and Vrije Universiteit Brussel (VUB) have demonstrated a 0.22mm2 CMOS resistive charge-based direct launch digital transmitter with -159dBc/Hz out-of-band noise. The achievement paves the way to small form-factor SAW-less transmitter implementations enabling advanced wireless communication systems including all the cellular standards 3G, 4G and future 5G.
Analog transmitters are less suitable for integration in advanced CMOS nodes. Digital transmitters are more compact and more robust to transistor imperfections and mismatches compared to analog transmitters, but they typically fall short with respect to high-end performance requirements such as out-of-band noise and spurious emission. Imec and VUB overcome this with a new transmitter architecture that combines the best of both worlds. The incremental-charge-based digital-to-analog (QDAC) conversion, allows full direct digital control of the transmitted signal, while at the same time enables intrinsic noise filtering that reduces out-of-band noise and alias components to state-of-the-art levels.
The presented prototype features resistor-based QDACs that deliver the required RF power efficiently direct to the 50? output load, omitting the need for a power-hungry PA driver. A peak output power of 3.5dBm and a phase noise of -159Bc/Hz at 45MHz offset from both 900MHz and 2.4GHz modulated carriers is achieved, with an Error Vector Magnitude (EVM) performance of -36dB for a 64-QAM modulated signal. With an active area of only 0.22mm2 this architecture is extremely suitable for integration in nanoscale RF CMOS SoCs.
These breakthrough results were achieved in the framework of imec’s industrial affiliation program on reconfigurable radio technologies, including industrial partners such as HiSilicon, Panasonic, Murata, Sony and Cadence. The research also received funding through the Flemish HERCULES project VeRONICa.
This press release can be downloaded at http://www2.imec.be/be_en/press/imec-news/resistive-charge-based-direct-launch-digital-transmitter.html
About imec
Imec performs world-leading research in nanoelectronics. Imec leverages its scientific knowledge with the innovative power of its global partnerships in ICT, healthcare and energy. Imec delivers industry-relevant technology solutions. In a unique high-tech environment, its international top talent is committed to providing the building blocks for a better life in a sustainable society. Imec is headquartered in Leuven, Belgium, and has offices in Belgium, the Netherlands, Taiwan, US, China, India and Japan. Its staff of more than 2,300 people includes almost 700 industrial residents and guest researchers. In 2014, imec’s revenue (P&L) totaled 363 million euro. Further information on imec can be found at www.imec.be. Stay up to date about what’s happening at imec with the monthly imec magazine, available for tablets and smartphones (as an app for iOS and Android), or via the websitewww.imec.be/imecmagazine
Imec is a registered trademark for the activities of IMEC International (a legal entity set up under Belgian law as a “stichting van openbaar nut”), imec Belgium (IMEC vzw supported by the Flemish Government), imec the Netherlands (Stichting IMEC Nederland, part of Holst Centre which is supported by the Dutch Government), imec Taiwan (IMEC Taiwan Co.) and imec China (IMEC Microelectronics (Shanghai) Co. Ltd.) and imec India (Imec India Private Limited).
About VUB
Vrije Universiteit Brussel, in the heart of Europe
Over 14,200 students, representing more than 120 nationalities study at VUB to take the next step in their career. 3000 of our students – more than 21% of our student population – are international students, making our institute a vibrant and truly global one.
VUB supports more than 100 English-taught programs with both outstanding research and a modern campus. Everything you need is at your fingertips and available on-site, near Brussels’ bustling city center: an extensive library, modern computer labs, state-of-the-art sports facilities, and exciting restaurants as well as interesting cultural activities, language courses and an invaluable job service.
In VUB’s eight faculties, students can choose to study and explore beyond their own discipline where they can exchange experiences, cultures, ideas and values. The University’s open-door policy means students build rapport with both faculty members and assistants, and staff are happy to answer student questions. Small group workshops are also in place to provide close interaction and hands-on experience.
Thanks to its expertise and location in Brussels, VUB is an ideal partner for prestigious research and education with an outlook on Europe and the world. With a research budget of EUR 86 Million, VUB covers some 2,200 publications and 24 reported inventions annually, supporting 150 research groups.
VUB is a haven for education and research, combining the best of both on American-style green campuses. It is listed in the top 200 QS World University Ranking and 251 – 275 in the Times Higher Education Ranking. The university has more than 75 cooperation contracts in 38 countries. It offers postgraduate degrees in English and awards Bachelor’s and Master’s degrees in a range of academic fields covering human sciences, life sciences and medicine, sciences and engineering. Doctorates are offered in all subjects for which the university issues academic degrees. VUB counts more than 1,800 PhD students.
