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The world’s first single-chip RF transceiver to support 5G sub-6-GHz new radio (NR) and long-term evolution (LTE) E-UTRA New Radio-Dual Connectivity (EN-DC) in 14-nm FinFET CMOS technology is presented. The single-chip transceiver integrates identical primary and diversity receivers (RXs) with seven pipelines for supporting four inter-band carrier aggregation (CA) with three 4 $\times $ 4 MIMO, two independent transmitter (TX) chains, eight frequency synthesizers for RX and TX, and on-chip digitally controlled crystal oscillator (DCXO) to reduce the phase noise and bill of material (BOM) cost. The receiver features 12 single-ended low-noise amplifiers (LNAs) with wideband characteristics. With the help of the proposed pipeline structure and frequency-band switchable transformer, the die size can be reduced despite covering the whole frequency range from 2G to sub-6-GHz 5G NR. It achieves the noise figure (NF) from 6.5 to 9.3 dB, +3-dBm out-of-band (OOB) IIP3, more than +70-dBm OOB IIP2 after calibration. For the transmitter, low RX-band noise and harmonic suppression technique are applied to support surface acoustic wave (SAW)-less architecture, and the bandwidth control of the baseband filter is implemented for the digital pre-distortion (DPD) operation of 100-MHz BW in NR transmit data. The measured error vector magnitudes (EVMs) in 4G and 5G bands of n79 are −39.5 dB at +4-dBm output power and −33.9 dB at +3.06-dBm output power, respectively, and the measured RX-band noise of 2G is −163 dBc at 20-MHz offset. The RX consumes 18 mW at LTE 1-CA mode and the TX consumes 350 mW at n79.

This paper presents a wide dynamic range (DR) CMOS root-mean-square power detector with a temperature variation compensation technique in a 28-nm CMOS process. The cascaded gain amplifiers and squaring circuits in the proposed power detector can achieve wide DR with the power level segmented detection method using a switch driver with the help of a modem. A 12-bit current digital-to-analog converter is used to calibrate dc offset in the power detector with 25- $\mu{\hbox{V}}$ steps to improve the accuracy. Measured DR is more than 40 dB from 700 MHz to 4 GHz. A temperature compensation bias circuit improves the performance of the detector with maximum 0.8-dB error over the temperature range $-{\hbox{30 }}^{\circ}{\hbox{C}}\sim {\hbox{90 }}^{\circ}{\hbox{C}}$ . The chip area is 333 $ \mu{\hbox{m}}\times$ 450 $\mu{\hbox{m}}$ and the power consumption is from 5.8 to 11.8 mW depending on the input power using a 1.8-V power supply.

This paper presents a wideband transformer-coupled CMOS power amplifier (PA). On-chip transmission-line transformers are used as key components of matching networks at output, input, and interstage. The wideband on-chip transformer is harnessed without any additional inductive devices so that a wideband power characteristic can be achieved. The PA is fabricated using a 0.18-μm CMOS process. It provides a saturated output power of 21.5 dBm with the power-added efficiency (PAE) of 20.3%, and the output 1-dB gain-compressed power (P1 dB) is 20.2 dBm with the PAE of 14.8% at 9.5 GHz, respectively. The small-signal gain is 25.3 dB and the 3-dB bandwidth is 6.5 GHz (6.5-13 GHz). The die area is 1.34 mm × 0.47 mm. Among the reported X/Ku-band CMOS PAs, this amplifier achieves the highest figure of merit, and also shows suitable performances for phased-array systems.

This paper reports new RF microelectromechanical systems (MEMS) switches actuated by the combination of electromagnetic and electrostatic forces for low-voltage and low-power operation. The proposed RF MEMS switches have utilized the proper combination of two actuation mechanisms: taking advantage of the large actuation force from electromagnetic actuation for initial movement and the low-power feature from electrostatic actuation for holding the actuator position. Both series- and shunt-type switches have been implemented using the proposed actuation mechanism. From the fabricated switches, feasibility of operation has been successfully demonstrated. The fabricated switches can be operated within several hundred microseconds. In the series-type switch, the isolation has been measured as -34dB and insertion loss as -0.37dB at 20 GHz. In the shunt type switch, the isolation is -20.7dB and insertion loss is -0.85dB at 19.5 GHz. The proposed RF MEMS switches are mechanically robust and the combination of electromagnetic and electrostatic actuations makes it possible to achieve excellent switching characteristics at low power and low voltage below 5 V.