A 1.5-V 45-mw direct-conversion WCDMA receiver IC in 0.13-μm CMOS

Digitally Enhanced Alternate Path Linearization of RF Receivers

“…A common solution to the dc offset issue in UMTS receivers is to use highpass filtering at baseband [4,5,24], with a cutoff frequency no greater than 10 kHz [24]. In this work, highpass filtering at 10 kHz is performed in the digital domain for both main and alternate paths to remove the dc offset of the complete analog portion of the receiver, including the ADC.…”

“…In the alternate path digital domain an IIR fixed equalization filter also exists, which accounts for most of the known LTI path mismatch between the main and alternate paths. It is posited that calibration of this digital IIR filter is unnecessary, as the use of automatic calibration in the analog baseband postfilter to maintain a relatively constant frequency response over PVT variation is common practice in cellular receivers [4,5,24]. The implemented version of the adaptive equalizer is shown in Fig.…”

“…24 Measured results of a modified two-tone test: (a) for proposed enhanced complex NLMS architecture; (b) for canonical complex NLMS architecture.…”

Equalization of Third-Order Intermodulation Products in Wideband Direct Conversion Receivers

“…A common solution to the dc offset issue in UMTS receivers is to use high-pass filtering at baseband [7], [8], [37], with a cutoff frequency no greater than 10 kHz [37]. In this work, high-pass filtering at 10 kHz is performed in the digital domain for both main and alternate paths to remove the dc offset of the complete analog portion of the receiver, including the ADC.…”

Trend of wireless communication systems and wide-band circuits

“…For instance, with regard to IEEE802.11, the number of presentations was previously one each for 11a and 11b in 2001 [1,2] but subsequently increased to four each in 2003 [3][4][5][6][7][8][9][10]. With regard to UMTS, two presentations in 2001 [11,12] were followed by four in 2003 [13][14][15][16]. Hence, the degree of attention to wider bandwidth has been extremely high for the past two years.…”