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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.

Signage systems are visual information systems that indicate the direction, allow for identification, and show safety information and regulations to occupants via graphics or text during emergencies. Wayfinding is difficult in large and complex buildings, such as large shopping malls. Occupants can be disoriented while searching for their way in such buildings. This problem can be more serious in emergency situations, such as fires, than in normal situations. Signage systems can be helpful in solving this problem. Domestic and overseas standards on emergency signage systems specify that the signage should be noticeable, easy to read, and easy to understand. However, most regulations do not quantify the effectiveness of such signage systems under emergency situations. To address these issues, in this study, several experiments were conducted considering the viewing distance and angle using a backlit signage system, and changes in cognition under smoke conditions were analyzed. First, the concept of effective cognition area (ECA) was introduced to analyze the relationship between the viewing distance and angle. Experiments were conducted using a backlit emergency exit sign, and the changes in the ECA in a smoke situation were analyzed. Finally, the results of this study were compared with those of previous studies. Furthermore, the extent to which occupants can recognize the signage system was quantified. If the concept of ECA developed in this study is applied to the development of emergency signage design, more diverse evacuation scenarios could be designed.

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.

As LTE offers the best wireless experience as never before, people spend much more time on smartphones to enjoy internet surfing and social networking, etc. To further improve the LTE network efficiency, recently, the Power-Class 2 (PC2) High Power User Equipment (HPUE) applied to B41 is deployed. To support HPUE, RF transmitters (TXs) need to deliver higher output power while maintaining stringent linearity requirements of emission mask, especially for third-order Counter Intermodulation (CIM3) in one Resource Block (1RB) case. CIM3 can be improved by several techniques such as power mixers [1,2], Harmonic-Reject Mixers (HRM) [3], notch-filter mixers [4, 5] and digital TXs [6]. Power-mixer, HRM and digital TX solutions may not be suitable for HPUE due to power-efficiency limitations. The notch-filter mixer is based on a voltage-mode passive mixer with 25%-duty-cycle LO, and it reduces 3flo, which exactly corresponds to the component at 3flo-fbb, by employing an LC trap. However, the conventional series [4] or parallel [5] 3flo trap causes a significant insertion loss at flo, which exactly corresponds to the component at flo+fbb, due to the trade-off between its efficiency, 3flo suppression and tuning range. This work presents a new transformer-based notch filter mixer. In this structure, the 3flo suppression can automatically track the channel frequency resulting in a wide operation frequency range of 1.4GHz to 2.7GHz while both the power efficiency and 3flo suppression are improved compared with the conventional notch-filter mixer [4,5].

Objectives : The purpose of this study is to explore the trends of acupoints used for lumbar HIVD(Herniated Intervertebral Disc) and treatment and anatomical location of Hwatahyeopcheock. Methods : We searched the latest clinical studies on acupuncture treatment for lumbar HIVD(Herniated Intervertebral Disc) through domestic studies search. To analyze the data, we categorized them by year and article types of literatures and investigated often-used acupoints and acupuncture types for treatment by reading treatment part of every paper searched. Domestic and Chinese literatures related to Hwatahyeopcheock were also studied for its anatomical location. Results : Total 50 articles are searched and local points are more used than distant points for lumbar HIVD(Herniated Intervertebral Disc) and most of them showed curative effects. Back-su points were used the most and Hwatahyeopcheock use accounted for one-third of the articles. In the articles of Hwatahyeopcheock use, except for one, patients complained of both low back pain and radiating pain, and all of them showed positive results after treatment. Conclusions : Back su point is considered to have its meaning as physical region where patients feel pain including herniated disc level rather than the effect meridian system makes. Through document research and meridian muscle theory, we found that Hwatahyeopcheock means vertebral facet joint, intervertebral foramen and surrounding muscle, nerve, blood vessel and related spinal nerves.