WCDMA Multicarrier Receiver for Base-Station Applications

Low-noise amplifiers for WCDMA base-station receivers

“…2 [1]. In this design, the two gain modes have been implemented using separate cores, which use a mutual load resonator to combine the signal path.…”

“…In this paper, two different alternatives to implement an LNA for WCDMA base-station receivers are described. The LNA, which is often the most important block when pursuing high performance, is implemented as a part of a whole receiver, which includes quadrature mixers, frequency divider for local oscillator signal, low pass active baseband filters, and buffer amplifiers for an analog-to-digital converter [1], [2]. The simplified block diagram of the complete receiver is shown in Fig.…”

Programmable SiGe BiCMOS low-pass filter for a multicarrier WCDMA base-station receiver

“…2, is chosen due to a low sensitivity to component value mismatches. In contrast to the filter in [1], three different gain settings with 6 dB steps are implemented in the second stage of this filter (R3 and R4 in Fig. 2) to compensate for possible process variations (i.e.…”

“…By using a single multicarrier IC that does not need parallel blocks, the size and cost of the BS can be reduced [1,2]. However, since the number of adjacent channels allocated for different operators can vary, it would be advantageous if a single IC could be used to receive different number of channels [3].…”

“…In order to keep the requirements of the analog-to-digital converter (ADC) constant, the out-of-band blocking and interfering signals should be attenuated similarly in the low-pass filter (LPF) regardless of the number of the received channels. Thus, to receive one to four channels, the LPF designed for a multicarrier receiver presented in [3] can be programmed to four different À3-dB bandwidths, which cannot be done with the filter in [1]. To receive two or four adjacent channels, the À3-dB bandwidth of the LPF is set to 5 or 10 MHz, respectively.…”