A 0.6 – 3.6 GHz CMOS wideband demodulator for 4G mobile handsets

This paper presents a 0.6 - 3.6 GHz CMOS wideband demodulator dedicated to 4G Long Term Evolution - Advanced (LTE-A) mobile handsets. The circuit uses three paths 120° phase shifted from one another instead of only two 90° phase shifted I and Q paths, which is the conventional configuration encountered in the well-known in-phase/quadrature (I/Q) demodulator. Thus, the proposed architecture is less sensitive to phase mismatch and has therefore strong potential for wideband operation that will be mandatory in future LTE-A systems. Furthermore, an analog circuit integrated on-chip converts the three output paths to two, in order to be compatible with a conventional I/Q front-end architecture. The circuit was designed using the 0.13 μm HCMOS9GP process provided by ST Microelectronics. The chip size is 1.79mm×1.3mm and it consumes 11.5 mW. This very high bandwidth (over 140%) demodulator which is compliant with integration in LTE-A mobile handsets is to our knowledge one of the very few dealing with this topic.