%0 Journal Article
%T An Integrated 5£¿GHz Wideband Quadrature Modem for OFDM Gbit/s Transmission in SiGe:C BiCMOS
%A Klaus Schmalz
%A Eckard Grass
%A Frank Herzel
%A Maxim Piz
%J International Journal of Microwave Science and Technology
%D 2007
%I Hindawi Publishing Corporation
%R 10.1155/2007/47927
%X This paper presents a 5 GHz wideband I/Q modulator/demodulator for 650 MHz OFDM signal bandwidth, which is integrated with a 5 GHz phase locked loop for I/Q generation. The quadrature signals are derived from a 10 GHz CMOS VCO followed by a bipolar frequency divider. The phase noise at 1 MHz offset is −112 dBc/Hz for the modulator as well as for the demodulator. The chips were produced in a 0.25 μm SiGe BiCMOS technology. The signal-to-noise ratio (SNR) of transmitted/received OFDM signal and the corresponding I/Q mismatch versus baseband frequency are given. The modulator achieves an SNR of 22–23 dB, and the demodulator realizes an SNR up to 22 dB. The modulator reaches a data rate of 2.16 Gbit/s using 64 QAM OFDM, and the demodulator realizes 1.92 Gbits/s.
%U http://www.hindawi.com/journals/ijmst/2007/047927/abs/