An 11-band 3-10 GHz receiver in SiGeBiCMOS for multiband OFDM UWB communication

This work presents a receiver implementation for MB-OFDM UWB communication that enables 11 bands of operation covering 78% of the spectrum licensed by the FCC. First, important system-level considerations are discussed with basis on the specifications from the MB-OFDM standard. Next, the different circuit techniques employed in the implementation of the receiver are described. For the LNA design, a wideband impedance match network that takes into account the package components is introduced. A notch filter embedded in the LNA and its tuning mechanism are proposed to attenuate the interference from devices operating in the U-NII band from 5.15 to 5.35 GHz. Based on the results of a recent investigation on frequency planning for MB-OFDM radios, a compact 11-band fast-hopping synthesizer implementation is proposed for the receiver. The 264-MHz baseband section consists of a linear phase low pass filter and a programmable gain amplifier; it presents an in-band group delay variation of less than 0.6 ns and 42 dB of gain in steps of 2 dB. The IC is fabricated in a 0.25-mu m SiGe BiCMOS process, placed in a QFN package and mounted on FR-4 substrate for its characterization. Measurement results show a receiver gain of 78-67 dB and NF of 5-10 dB across the 11 bands from 3-10 GHz, while consuming 114 mA from a 2.5-V supply.