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CMOS millimeter-wave integrated circuits for next generation wireless communication systems
\"This book addresses in-depth technical issues, limitations, considerations and challenges facing millimeter-wave (MMW) integrated circuit and system designers in designing MMW wireless communication systems from the complementary metal-oxide semiconductor (CMOS) perspective. It offers both a comprehensive explanation of fundamental theories and a broad coverage of MMW integrated circuits and systems. CMOS Millimeter-Wave Integrated Circuits for Next Generation Wireless Communication Systems is an excellent reference for faculty, researchers and students working in electrical and electronic engineering, wireless communication, integrated circuit design and circuits and systems. While primarily written for upper-level undergraduate courses, it is also an excellent introduction to the subject for instructors, graduate students, researchers, integrated circuit designers and practicing engineers. Advanced readers could also benefit from this book as it includes many recent state-of-the-art MMW circuits.\" -- Provided by publisher.
Book
A survey of millimeter wave communications (mmWave) for 5G: opportunities and challenges
With the explosive growth of mobile data demand, the fifth generation (5G) mobile network would exploit the enormous amount of spectrum in the millimeter wave (mmWave) bands to greatly increase communication capacity. There are fundamental differences between mmWave communications and existing other communication systems, in terms of high propagation loss, directivity, and sensitivity to blockage. These characteristics of mmWave communications pose several challenges to fully exploit the potential of mmWave communications, including integrated circuits and system design, interference management, spatial reuse, anti-blockage, and dynamics control. To address these challenges, we carry out a survey of existing solutions and standards, and propose design guidelines in architectures and protocols for mmWave communications. We also discuss the potential applications of mmWave communications in the 5G network, including the small cell access, the cellular access, and the wireless backhaul. Finally, we discuss relevant open research issues including the new physical layer technology, software-defined network architecture, measurements of network state information, efficient control mechanisms, and heterogeneous networking, which should be further investigated to facilitate the deployment of mmWave communication systems in the future 5G networks.
Journal Article
5G mmWave patch antenna array with proximity sensing function for detecting user's hand grip on mobile terminals
We propose a new concept millimetre‐wave patch antenna that integrates the functions of an antenna and a capacitive proximity sensor to detect the hand grip state for 5G mobile terminals and compensate for the hand effect. The proposed antenna has the structure of a proximity‐coupled fed patch and functions as a proximity sensor by using the capacitance change of the patch that occurs when the user's hand approaches the patch. By observing the capacitance change at the centre of the patch operating in the TM01 mode, it is possible to simultaneously perform the functions of antenna and sensor without mutual interference. The proposed antenna is implemented as a 1 × 4 array. The experimental results show that it has a stable gain of 8.3 to 10.1 dBi at 26.5 to 29.5 GHz and can operate as a proximity sensor with a capacitance change of 200 fF according to the proximity of the hand. The authors propose a new concept millimetre‐wave patch antenna that integrates the functions of an antenna and a capacitive proximity sensor to detect the hand grip state for 5G mobile terminals and compensate for the hand effect. The proposed antenna has the structure of a proximity‐coupled fed patch and functions as a proximity sensor by using the capacitance change of the patch that occurs when the user's hand approaches the patch.
Journal Article
Photodissociation transition states characterized by chirped pulse millimeter wave spectroscopy
The 193-nm photolysis of CH₂CHCN illustrates the capability of chirped-pulse Fourier transform millimeter-wave spectroscopy to characterize transition states. We investigate the HCN, HNC photofragments in highly excited vibrational states using both frequency and intensity information. Measured relative intensities of J = 1–0 rotational transition lines yield vibrational-level population distributions (VPD). These VPDs encode the properties of the parent molecule transition state at which the fragment molecule was born. A Poisson distribution formalism, based on the generalized Franck–Condon principle, is proposed as a framework for extracting information about the transition-state structure from the observed VPD. We employ the isotopologue CH₂CDCN to disentangle the unimolecular 3-center DCN elimination mechanism from other pathways to HCN. Our experimental results reveal a previously unknown transition state that we tentatively associate with the HCN eliminated via a secondary, bimolecular reaction.
Journal Article
Energy-efficient design for mmWave-enabled NOMA-UAV networks
Owing to the recent advances of non-orthogonal multiple access (NOMA) and millimeter-wave (mmWave), these two technologies are combined in unmanned aerial vehicle (UAV) networks in this paper. However, energy efficiency has become a significant metric for UAVs owning to their limited energy. Thus, we aim to maximize the energy efficiency for mmWave-enabled NOMA-UAV networks by optimizing the UAV placement, hybrid precoding and power allocation. However, the optimization problem is complicated and intractable, which is decomposed into several sub-problems. First, we solve the UAV placement problem by approximating it into a convex one. Then, the hybrid precoding with user clustering is performed to better reap the multi-antenna gain. Particularly, three schemes are proposed, where the cluster head selection algorithm is adopted while considering different equivalent channels of users. Finally, the power allocation is optimized to maximize the energy efficiency, which is converted to convex and solved via an iterative algorithm. Simulation results are provided to evaluate the performance of the proposed schemes.
Journal Article
Millimeter-Wave Measurement of Anisotropy Permittivity for Liquid Crystals Based on Open Resonator Method
The liquid crystal (LC) can be applied in the reconfigurable RF devices due to its excellent tuning capacity of dielectric property. Accurate characterization of its anisotropic permittivity is critical for the optimization of high-frequency or high-speed circuits and components. This work developed a nondestructive quasi-optical Fabry-Perot open resonator and the anisotropic dielectric properties of LC were measured at W band. The dielectric anisotropy of LC was experimentally studied in (75~110) GHz, with the tunability about 22%.
Journal Article
Applicable Near-Field Millimeter Wave Imaging Technology for Human Body Security Based on Scanning 1D Non-uniform Sparse Arrays
Employing a sparse array is an effective method to reduce the cost of millimeter wave (MMW) imaging systems. However, the sparse array can lead to uneven MMW sampling along the array dimension, which renders the highly efficient range migration algorithm (RMA) inapplicable. While the back projection algorithm (BPA) can meet the needs of uneven sampling, its efficiency is too low. Therefore, this paper proposes a novel MMW image reconstruction algorithm, named range migration and back projection algorithm (RMBPA), which combines RMA and BPA. The RMBPA uses the RMA for focusing and solving in the mechanically scanned and range-focused directions with uniform sampling and employs the BPA for aperture synthesis in the direction with non-uniform sampling. Building upon the RMBPA, this paper introduces an innovative low-cost planar scanning MMW imaging technology based on a one-dimensional (1D) sparse array. Simulation and experimental results demonstrate that the imaging technology can achieve a spatial resolution of 5 mm in the Ka-band, clearly discerning the human silhouette and handgun model in human body imaging. The image quality is comparable to that of non-sparse array imaging under the same conditions, with imaging efficiency slightly lower than RMA but significantly higher than BPA. The technology can get a 1 m × 2 m area imaging in only 2.0 s, offering significant application value.
Journal Article
3DRIED: A High-Resolution 3-D Millimeter-Wave Radar Dataset Dedicated to Imaging and Evaluation
Millimeter-wave (MMW) 3-D imaging technology is becoming a research hotspot in the field of safety inspection, intelligent driving, etc., due to its all-day, all-weather, high-resolution and non-destruction feature. Unfortunately, due to the lack of a complete 3-D MMW radar dataset, many urgent theories and algorithms (e.g., imaging, detection, classification, clustering, filtering, and others) cannot be fully verified. To solve this problem, this paper develops an MMW 3-D imaging system and releases a high-resolution 3-D MMW radar dataset for imaging and evaluation, named as 3DRIED. The dataset contains two different types of data patterns, which are the raw echo data and the imaging results, respectively, wherein 81 high-quality raw echo data are presented mainly for near-field safety inspection. These targets cover dangerous metal objects such as knives and guns. Free environments and concealed environments are considered in experiments. Visualization results are presented with corresponding 2-D and 3-D images; the pixels of the 3-D images are 512×512×6. In particular, the presented 3DRIED is generated by the W-band MMW radar with a center frequency of 79GHz, and the theoretical 3-D resolution reaches 2.8 mm × 2.8 mm × 3.75 cm. Notably, 3DRIED has 5 advantages: (1) 3-D raw data and imaging results; (2) high-resolution; (3) different targets; (4) applicability for evaluation and analysis of different post processing. Moreover, the numerical evaluation of high-resolution images with different types of 3-D imaging algorithms, such as range migration algorithm (RMA), compressed sensing algorithm (CSA) and deep neural networks, can be used as baselines. Experimental results reveal that the dataset can be utilized to verify and evaluate the aforementioned algorithms, demonstrating the benefits of the proposed dataset.
Journal Article
High-Isolation MIMO Antenna for 5G Millimeter-Wave Communication Systems
The work in this article presents the design and realization of a low-profile, four-port MIMO antenna supporting fifth-generation (5G) wireless applications operating at a millimeter-Wave (mm-Wave) band. Each MIMO antenna is a 2-element array fed with a corporate feeding network, whereas the single antenna is a patch with a bow-tie slot at the center and slits at the edges. The vertical and horizontal slots are incorporated as a Defected Ground Structure (DGS) to optimize the antenna performance. In addition, a slotted zig-zag decoupling structure is etched from edge to edge on the top side to enhance the isolation. Significant isolation (>−40 dB) is achieved between antenna elements by employing spatial and polarization diversity techniques. The proposed antenna covers the 5G mm-Wave band with a −10 dB bandwidth ranging from 27.6–28.6 GHz, whereas the maximum gain attained for the proposed structure is 12.02 dBi. Moreover, the lower correlation values, higher diversity gain, and lower channel capacity loss make it a suitable contender for 5G MIMO applications at the mm-Wave range.
Journal Article