A Highly Linear Receiver Using Parallel Preselect Filter for 5G Microcell Base Station Applications

By introducing three different techniques, this article, for the first time, presents a wideband highly linear receiver (RX) capable of handling blocking scenarios in fifth-generation (5G) microcell base station applications.First, a parallel preselect filter is introduced to satisfy the base station co-location blocking requirements.Next, a combination of third-order RF and baseband (BB) filters is adopted to attenuate close-in blockers by a -120 dB/dec roll-off.Finally, a translational feedback network is proposed to reduce the in-band gain ripple to below 0.5 dB and provide better than -19 dB input matching.Fabricated in the 40-nm CMOS technology, the proposed RX occupies a core area of 0.8 mm 2 and consumes 108-176 mW from a 1.3 V supply over the RX's 0.5-3-GHz operating frequency.It achieves a 3-dB bandwidth of 150 MHz and a noise figure (NF) of 2.6-3.9 dB over the RX frequency range.Activating the parallel preselect filter degrades the NF by as little as 1.2 dB in the worst case.The RX shows a ≥97.5% throughput when receiving a 100-MS/s quadrature phase shift keying (QPSK) signal with 7.5-dB SNR and achieves a -9.7 dB error vector magnitude (EVM) while facing a -15 dBm continuous-wave (CW) blocker only 20 MHz away from the desired 100-MS/s QPSK signal with 12.3-dB SNR, thus satisfying the 3rd generation partnership project (3GPP) requirements with sufficient margin.Index Terms-Blocker-tolerant, current-mode receiver (RX), fifth-generation (5G), harmonic rejection (HR), high-order bandpass filter, preselect filter, software-defined radio, wideband RX. I. INTRODUCTIONF IFTH-GENERATION (5G) mobile communication has recently been introduced for sub-6 GHz radios to satisfy the relentless customer demands for higher data rates.However, it imposes stringent design requirements on the base station receivers (RXs).First, the RF bandwidth (BW RF ) can be as high as 200 MHz, demanding higher power consumption for the baseband (BB) amplifiers.Second, an out-of-band close-in blocker with -15 dBm power can appear at only 20-MHz offset frequency from the bandwidth edge, thus requiring sharp filtering.Third, a sub-3-dB noise figure (NF) is