0.8-5.2GHz band SiGe-MMIC Q-MOD for multi-band multi-mode direct conversion transmitters

In order to realize multiband multimode transmitters for the 4th generation mobile communication systems based on software define radio (SDR) technology, 0.8-5.2GHz broad-band direct conversion quadrature modulator (Q-MOD) has been fabricated in 0.35/spl mu/m SiGe BiCMOS process. The circuit combination of a static frequency divider and a poly phase filter (PPF) enables higher 90degree phase accuracy than that of the static frequency divider alone. By employing this 90 degree power divider, the fabricated Q-MOD achieves EVM of 4.0/3.1% rms at 0.8/2.1GHz W-CDMA transmission and 2.5% rms at 5.2GHz wireless-LAN (IEEE 802.11a) transmission.