Download or read book Concurrent Dual band Doherty Power Amplifiers for Carrier Aggregation written by Mingming Liu and published by . This book was released on 2017 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carrier aggregation is the main feature of the Long Term Evolution advanced (LTE-A) standard to increase the spectral efficiency and communication bandwidth. It calls for wireless transmitters to be multi-band and multi-standard to meet the demands of various deployment scenarios. In addition, these transmit radios must efficiently amplify signals characterized with a high peak-to-average power ratio (PAPR), which is caused by advanced modulation schemes. These two factors highlight the need for the multi-band Doherty power amplifier (DPA), which allows the transmitter remain in high efficiency at back-off power levels and maintain that high efficiency over multiple frequency bands. In this work, a novel output combining network is presented for the dual-band DPA design with extended fractional bandwidth for carrier aggregated signals. The proposed output combiner employs a modified Pi-shape network, which enables the absorption of output capacitances from both the main and peaking devices and eliminates the need for phase offset lines which are major sources of bandwidth limitation in the existing multiband DPAs. In addition to performing the impedance inversion, the proposed combiner incorporates the biasing feeds and presents small low-frequency impedances to both the main and peaking transistors. The inclusion of the bias feeds and small low low-frequency impedance feature improves the linearizability of the DPA when stimulated with concurrent dual-band modulated signals. Lastly, by using the gain contour at the back-off power level, the non-linear AM-AM response caused by the varying input capacitance of the main transistor is mitigated. The proposed dual-band output power combiner and the back-off gain contour technique were applied to design of a dual-band two-way Doherty PA using the commercialized 25W Gallium Nitride (GaN) transistor. Measurement of the two-way DPA shows a gain of 7.5- 9.5 dB at 2.05 - 2.3 GHz and 9 - 11 dB at 3.2 - 3.62 GHz. The efficiency at 6 dB back off is greater than 49% and 47% across the two frequency bands. The linearizability of the dual-band DPA is validated using various carrier aggregated signals. The PA exhibits linear behaviour when driven by up to 80 MHz intra-band carrier aggregated signal and 20 MHz concurrent dual-band signal after DPD. Additionally, carrier aggregated signals usually lead to a PAPR value between 8-10 dB. The efficiency of classic two-way DPA deteriorates when dealing with such signals. To cope with the efficiency deterioration, a three-way DPA was designed. Simulations of the three-way DPA show that the gain is greater than 9 dB within the two frequency bands, 2.05 - 2.32 GHz and 3.35 - 3.65 GHz. The efficiency at 10-dB back-off is greater than 40% in the two frequency bands.

Download or read book Concurrent Multi band Envelope Tracking Power Amplifiers for Emerging Wireless Communications written by Hassan Sarbishaei and published by . This book was released on 2014 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emerging wireless communication is shifting toward data-centric broadband services, resulting in employment of sophisticated and spectrum efficient modulation and access techniques. This yields communication signals with large peak-to-average power ratios (PAPR) and stringent linearity requirements. For example, future wireless communication standard, such as long term evolution advanced (LTE-A) require adoption of carrier aggregation techniques to improve their effective modulation bandwidth. The carrier aggregation technique for LTE-A incorporates multiple carriers over a wide frequency range to create a wider bandwidth of up to 100MHz. This will require future power amplifiers (PAs) and transmitters to efficiently amplify concurrent multi-band signals with large PAPR, while maintaining good linearity. Different back-off efficiency enhancement techniques are available, such as envelope tracking (ET) and Doherty. ET has gained a lot of attention recently as it can be applied to both base station and mobile transmitters. Unfortunately, few publications have investigated concurrent multi-band amplification using ET PAs, mainly due to the limited bandwidth of the envelope amplifier. In this thesis, a novel approach to enable concurrent amplification of multi-band signals using a single ET PA will be presented. This thesis begins by studying the sources of nonlinearities in single-band and dual-band PAs. Based on the analysis, a design methodology is proposed to reduce the sources of memory effects in single-band and dual-band PAs from the circuit design stage and improve their linearizability. Using the proposed design methodology, a 45W GaN PA was designed. The PA was linearized using easy to implement, memoryless digital pre-distortion (DPD) with 8 and 28 coefficients when driven with single-band and dual-band signals, respectively. This analysis and design methodology will enable the design of PAs with reduced memory effects, which can be linearized using simple, power efficient linearization techniques, such as lookup table or memoryless polynomial DPD. Note that the power dissipation of the linearization engine becomes crucial as we move toward smaller base station cells, such as femto- and pico-cells, where complicated DPD models cannot be implemented due to their significant power overhead. This analysis is also very important when implementing a multi-band ET PA system, where the sources of memory effects in the PA itself are minimized through the proposed design methodology. Next, the principle of concurrent dual-band ET operation using the low frequency component (LFC) of the envelope of the dual-band signal is presented. The proposed dual-band ET PA modulates the drain voltage of the PA using the LFC of the envelope of the dual-band signal. This will enable concurrent dual-band operation of the ET PA without posing extra bandwidth requirements on the envelope amplifier. A detailed efficiency and linearity analysis of the dual-band ET PA is also presented. Furthermore, a new dual-band DPD model with supply dependency is proposed in this thesis, capable of capturing and compensating for the sources of distortion in the dual-band ET PA. To the best of our knowledge, concurrent dual-band operation of ET PAs using the LFC of the envelope of the dual-band signal is presented for the first time in the literature. The proposed dual-band ET operation is validated using the measurement results of two GaN ET PA prototypes. Lastly, the principle of concurrent dual-band ET operation is extended to multi-band signals using the LFC of the envelope of the multi-band signal. The proposed multi-band ET operation is validated using the measurement results of a tri-band ET PA. To the best of our knowledge, this is the first reported tri-band ET PA in literature. The tri-band ET PA is linearized using a new tri-band DPD model with supply dependency.

Download or read book Recent Technical Developments in Energy Efficient 5G Mobile Cells written by Raed A. Abd-Alhameed and published by MDPI. This book was released on 2020-06-17 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses the true innovation in engineering design that may be promoted by blending together models and methodologies from different disciplines, and, in this book, the target was exactly to follow this approach to deliver a new disruptive architecture to deliver these next-generation mobile small cell technologies. According to this design philosophy, the work within this book resides in the intersection of engineering paradigms that includes “cooperation”, “network coding”, and “smart energy-aware frontends”. These technologies will not only be considered as individual building blocks, but re-engineered according to an inter-design approach resulting in the enabler for energy efficient femtocell-like services on the move. The book aims to narrow the gap between the current networking technologies and the foreseen requirements that are targeted at the future development of the 5G mobile and wireless communications networks in terms of the higher networking capacity, the ability to support more users, the lower cost per bit, the enhanced energy efficiency, and adaptability to new services and devices (for example, smart cities, and the Internet of things (IoT)).

Download or read book Two Port Network Theory Based Design Method of Broadband Doherty Power Amplifier written by Yue Li and published by . This book was released on 2018 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: LTE-Advanced (LTE-A) is a widely used communication standard and it mainly features Carrier aggregation (CA). CA increases the user data rate and efficiently exploits the fragmented spectrum by combining various carrier frequencies. The intrinsic multi-band and multi-standard of CA, along with the existing high peak-to-average power ratio (PAPR), brings the challenges of broadband requirement and back-off (BO) efficiency enhancement when designing radio frequency power amplifiers (PA). The above two challenges inspire research interest in designing of broadband Doherty power amplifiers (DPAs), which maintain the high efficiency at BO power level and perform constantly versus frequency. In this work, the continuous design space was discussed. Output combining and matching network (OCMN) and its impact on the impedances shown to the two transistors were analyzed based on two port network theory. ABCD parameters of matching networks was formulated to accommodate continuous class-B (class-J) operation to DPAs. Second harmonic was terminated to avoid clipping and efficiency degradation. By enlarging design space, the bandwidth was substantially expanded. The proposed design methodology allowed the adsorption of parasitics which was the one of the bandwidth limiting factor. To validate the proposed methodology, an 8 Watts DPA was simulated to operate from 3 GHz to 5 GHz using Cree Gallium nitride (GaN) High-electron-mobility transistors (HEMTs). And simulation results showed that the 6dB BO efficiency was above 40% and Peak-envelope-power (PEP) of 50% over the frequency range of 3GHz to 5GHz. The Doherty power amplifier prototype is fabricated on substrate of Rogers4003C and assembled in house. Continuous wave measurement showed that the PA could provide 8.2 - 10.6 dB gain in the frequency band of 2.7 to 4.3 GHz. The 6 dB back off efficiency was 40% to 43%. And at peak power, the drain efficiency reached 48% to 60%. 80 MHz inter-band modulated signal and 15MHz dual band signal measurement were carried out to investigate the linearizability. In the inter-band measurement, average power around 33dBm and average drain efficiency of 46% was obtained with PAPR of 6.4 dB. ACLR above 48.7 dBc after DPD verified the easiness of linearization for this PA. Dual band measurement using two carriers at 2.8 and 3.2 GHz showed even when the PAPR of two band were 7.6 and 8.0 dB separately, average power of 32.3 dBm power can still be extracted with average efficiency of 40.5%. ACLR of 49.5 and 46.7 dBc of those two bands were good endorsement of the capability of inter-band concurrent amplification.

Download or read book High Efficiency Load Modulation Power Amplifiers for Wireless Communications written by Zhancang Wang and published by Artech House. This book was released on 2017-06-30 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: This cutting-edge resource presents a complete and systematic overview of the practical design considerations of radio frequency (RF) high efficiency load modulation power amplifiers (PA) for modern wireless communications for 4G and beyond. It provides comprehensive insight into all aspects of load modulation PA design and optimization not only covering design approaches specifically for passive and active load modulation operation but also hybrid with dynamic supply modulation and digital signal processing algorithms required for performance enhancement. Passive load impedance tuner design, dynamic load modulation PA, active load modulation PA and Doherty PA design for efficiently enhancement are explained. Readers find practical guidance into load modulation PA design for bandwidth extension, including video bandwidth enhancement techniques, broadband dynamic load amplifiers, topology selection, design procedures, and network output. This book presents the evolution and integration of classical load modulation PA topologies in order to meet new challenges in the field.

Download or read book Extended Bandwidth Doherty Power Amplifier for Carrier Aggregated Signals written by Mehdi Naseri Ali Abadi and published by . This book was released on 2014 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the conventional classes of power amplifiers the efficiency drops at power back-off, whereas in order to maximize the spectral efficiency and data rate, wireless communication standards employ signals with high peak to average power ratio. This results in low average efficiency for power amplifiers, which in turn results in heavy cooling requirements and damage to the environment. To improve the low back-off efficiency Doherty technique has been widely investigated. But, the conventional Doherty power amplifiers are fairly narrowband, while modern transmitters are needed to support multiple standards and operate at multiple frequency bands. This thesis proposes two novel output combiners for Doherty power amplifiers with extended bandwidth. It will be shown analytically how the problem of wideband Doherty can be converted into an impedance synthesization problem. Then two networks to synthesize the desired impedance are proposed. To achieve the proper load modulation over a wide bandwidth, the first proposed combiner employs a quarter-wave short-circuited stub at the output of the peaking transistor and the second proposed combiner uses a parallel LC tank at the same node. In addition to inherent wideband characteristics, the proposed Doherty output combiners have three other important benefits. First, they present small low-frequency impedance for both the main and peaking transistors, which results in improved linearity and linearizability when the amplifier is concurrently driven with multi-band modulated signals. Second, the new combiners result in smaller group delay variation across the band compared to the conventional Doherty amplifier, which results in improved linearizability when the amplifier is driven with extra wideband modulated signals. Finally, the output capacitance of the peaking transistor can be easily absorbed into the combiners without compromising the performance of the amplifier. The thesis starts with an overview of the Doherty power amplifier principles and provides a bandwidth analysis for the conventional Doherty power amplifier. Then it continues with the new approach to extend the bandwidth of Doherty amplifiers with respect to requirements of multi-band transmission. Based on the proposed combiners, two Gallium Nitride 20 W Doherty power amplifiers have been designed and fabricated. The measurement results have been provided to validate the developed theory. The first amplifier covers 1.72 to 2.27 GHz and the second one covers 700 to 950 MHz and both maintain higher than 48 % of drain efficiency at 6 dB back-off across the band. The two amplifiers are successfully linearized when driven with carrier aggregated modulated signals.

Download or read book Microwave RF Components for 5G Front End Systems written by Naser Ojaroudi Parchin and published by AVID SCIENCE. This book was released on 2019-12-16 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the development of mobile 4G communication system, people’s requirements for the speed of wireless communication are rapidly increasing. In order to meet this need, the research and development of the fifth generation (5G) wireless systems has been carried out. Compared with previous generation (1G~4G), 5G will have significant improvements in transmission rate, latency, mobility and so on. The book “Microwave/RF Components for 5G Front-End Systems” is outlines the simulation, design, and fabrication of microwave components including Antennas, Filters, and Power Amplifiers for 5G wireless communications. In addition, exhaustive reviews have been presented, classifying the various types and applications of reconfigurable antennas, Filters and amplifiers for current and future wireless networks.

Download or read book Broadband Doherty Power Amplifiers with Enhanced Linearity for Emerging Radio Transmitters written by Hamed Golestaneh and published by . This book was released on 2016 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ever-increasing demand for utilizing wireless spectra has led to development of spectrally efficient radio systems. While these systems offer much higher data throughput, they employ more sophisticated modulation schemes, which result in wideband signals with high peak-to-average power ratios. These signal characteristics significantly complicate the design of RF transmitters, particularly power amplifiers, in terms of power efficiency and linearity requirements. Furthermore, upcoming wireless standards, such as long term evolution advanced (LTE-A) require adoption of carrier aggregation which incorporates multiple component carriers to yield aggregated channels of larger bandwidth (up to 100 MHz). On the other hand, the emerging systems are expected to support legacy standards with minimum area, cost, and power overhead, and thus call for highly-efficient linear broadband power amplifiers capable of efficiently amplifying concurrent modulated signals located over a broad carrier frequency range. This thesis focuses on Doherty power amplifiers (DPAs) with extended high-efficiency range, enhanced bandwidth and improved linearity as a solution for high-efficiency multi-band multi-standard transmitters. It addresses three major concerns associated with DPAs, namely, back-off efficiency, bandwidth, and linearity.

Download or read book Linearization of Concurrent Dual band Power Amplifier Using Digital Predistortion written by Naveen Naraharisetti and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: With the current demand for higher data-rate transmissions, complex envelop techniques like wideband code division multiple access (WCDMA) and orthogonal frequency division multiplexing (OFDM) techniques are employed because of their high spectral efficiency. However these modulated schemes which feature non-constant envelop signals with high peak to average power ratio (PAPR) also impose strict linearity requirements on the PAs. A digital predistortion is used to linearize the PA for its robustness and easy implementation on an FPGA. The complexity of the DPD design is alleviated using widely spaced carriers and frequency selective technique.

Download or read book The Design of Concurrent Dual Band Envelope Tracking Power Amplifier for Basestations written by Yiqiao Lin and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The linearity and efficiency of a transmitting system is largely determined by its last stage component: the Power Amplifier (PA). In the past century, engineers and scientists have pioneered various architectures to optimize the PA performance - most notably the linearity and efficiency, as these quantities directly correspond to signal integrity and cost, respectively. In this dissertation, the design, implementation, and measurement results of a concurrent dual-band envelope tracking (ET) PA system is detailed. The dual-band PA system incorporates a new envelope tracking (ET) methodology which relaxes the large bandwidth requirement typically placed on supply modulators for dual-band applications, resulting in significant efficiency improvement. Afterwards, the PA linearity optimized through the use of a new, highly stable, and scalable digital predistortion (DPD) scheme, viable for both constant supply as well as modulated supply (ET) dual-band PAs. The developed ET and multi-dimentional DPD system methodologies are then verified using a 10W peak gallium-nitride (GaN) ET PA operating with a dual-band input based on LTE and WCDMA signals, with center frequencies spaced by 310 MHz. The testbed is based on a Altera FPGA Stratix IV and two Analog Device mixed signal DPD boards. The proposed method provides a performance improvement as high as 17 dB in terms of normalized mean square error (NMSE) and 4.6 dB in terms of adjacent channel power ratio (ACPR) in comparison to the conventional dual-band memory polynomial method including ET.

Download or read book A Novel 3 way Dual band Doherty Power Amplifier written by Ruwaybih Alsulami and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 5G System Design written by Patrick Marsch and published by John Wiley & Sons. This book was released on 2018-06-11 with total page 599 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive overview of the latest research and standardization progress towards the 5th generation (5G) of mobile communications technology and beyond. It covers a wide range of topics from 5G use cases and their requirements, to spectrum, 5G end-to-end (E2E) system architecture including core network (CN), transport network (TN) and radio access network (RAN) architecture, network slicing, security and network management. It further dives into the detailed functional design and the evaluation of different 5G concepts, and provides details on planned trials and pre-commercial deployments across the globe. While the book naturally captures the latest agreements in 3rd Generation Partnership Project (3GPP) New Radio (NR) Release 15, it goes significantly beyond this by describing the likely developments towards the final 5G system that will ultimately utilize a wide range of spectrum bands, address all envisioned 5G use cases, and meet or exceed the International Mobile Telecommunications (IMT) requirements for the year 2020 and beyond (IMT-2020). 5G System Design: Architectural and Functional Considerations and Long Term Research is based on the knowledge and consensus from 158 leading researchers and standardization experts from 54 companies or institutes around the globe, representing key mobile network operators, network vendors, academic institutions and regional bodies for 5G. Different from earlier books on 5G, it does not focus on single 5G technology components, but describes the full 5G system design from E2E architecture to detailed functional design, including details on 5G performance, implementation and roll-out.

Download or read book An Introduction to LTE written by Christopher Cox and published by John Wiley & Sons. This book was released on 2014-05-12 with total page 561 pages. Available in PDF, EPUB and Kindle. Book excerpt: Following on from the successful first edition (March 2012), this book gives a clear explanation of what LTE does and how it works. The content is expressed at a systems level, offering readers the opportunity to grasp the key factors that make LTE the hot topic amongst vendors and operators across the globe. The book assumes no more than a basic knowledge of mobile telecommunication systems, and the reader is not expected to have any previous knowledge of the complex mathematical operations that underpin LTE. This second edition introduces new material for the current state of the industry, such as the new features of LTE in Releases 11 and 12, notably coordinated multipoint transmission and proximity services; the main short- and long-term solutions for LTE voice calls, namely circuit switched fallback and the IP multimedia subsystem; and the evolution and current state of the LTE market. It also extends some of the material from the first edition, such as inter-operation with other technologies such as GSM, UMTS, wireless local area networks and cdma2000; additional features of LTE Advanced, notably heterogeneous networks and traffic offloading; data transport in the evolved packet core; coverage and capacity estimation for LTE; and a more rigorous treatment of modulation, demodulation and OFDMA. The author breaks down the system into logical blocks, by initially introducing the architecture of LTE, explaining the techniques used for radio transmission and reception and the overall operation of the system, and concluding with more specialized topics such as LTE voice calls and the later releases of the specifications. This methodical approach enables readers to move on to tackle the specifications and the more advanced texts with confidence.

Download or read book The Mountbatten Medal written by The Royal Life Saving Society Commonwealth and published by . This book was released on 2022 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: History of the RLSS Commonwealth Mountbatten Medal

Download or read book 2017 Sixth Asia Pacific Conference on Antennas and Propagation APCAP written by IEEE Staff and published by . This book was released on 2017-10-16 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Analysis, design, and development of various antennas Design of wide band antennas and small antennas Empirical, theoretical, and computational models of antennas and arrays Material properties and their applications in antennas Reconfigurable and tunable antennas, optical and nano antennas Antenna arrays and MIMO systems Signal processing for antennas Theoretical and computational methods of predicting wave propagation and sensing Characterization of propagation channels Applications in wireless communications, radar, and imaging systems Multiple antenna systems for spatial, polarization, pattern, and other diversity applications Measurement, specification, and standards of electrical quantities Measurement techniques for antennas, electromagnetic radiation, propagation, and scattering Fundamental and advanced theory, analytical and numerical solutions Radiation, scattering, radar cross section, propagation, and interaction with all media Inverse scattering

Download or read book Broadband RF and Microwave Amplifiers written by Andrei Grebennikov and published by CRC Press. This book was released on 2017-07-12 with total page 750 pages. Available in PDF, EPUB and Kindle. Book excerpt: Broadband RF and Microwave Amplifiers provides extensive coverage of broadband radio frequency (RF) and microwave power amplifier design, including well-known historical and recent novel schematic configurations, theoretical approaches, circuit simulation results, and practical implementation strategies. The text begins by introducing two-port networks to illustrate the behavior of linear and nonlinear circuits, explaining the basic principles of power amplifier design, and discussing impedance matching and broadband power amplifier design using lumped and distributed parameters. The book then: Shows how dissipative or lossy gain-compensation-matching circuits can offer an important trade-off between power gain, reflection coefficient, and operating frequency bandwidth Describes the design of broadband RF and microwave amplifiers using real frequency techniques (RFTs), supplying numerous examples based on the MATLAB® programming process Examines Class-E power amplifiers, Doherty amplifiers, low-noise amplifiers, microwave gallium arsenide field-effect transistor (GaAs FET)-distributed amplifiers, and complementary metal-oxide semiconductor (CMOS) amplifiers for ultra-wideband (UWB) applications Broadband RF and Microwave Amplifiers combines theoretical analysis with practical design to create a solid foundation for innovative ideas and circuit design techniques.

Download or read book Millimeter Wave Wireless Communications written by Theodore S. Rappaport and published by Pearson Education. This book was released on 2015 with total page 705 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Definitive, Comprehensive Guide to Cutting-Edge Millimeter Wave Wireless Design “This is a great book on mmWave systems that covers many aspects of the technology targeted for beginners all the way to the advanced users. The authors are some of the most credible scholars I know of who are well respected by the industry. I highly recommend studying this book in detail.” —Ali Sadri, Ph.D., Sr. Director, Intel Corporation, MCG mmWave Standards and Advanced Technologies Millimeter wave (mmWave) is today's breakthrough frontier for emerging wireless mobile cellular networks, wireless local area networks, personal area networks, and vehicular communications. In the near future, mmWave products, systems, theories, and devices will come together to deliver mobile data rates thousands of times faster than today's existing cellular and WiFi networks. In Millimeter Wave Wireless Communications, four of the field's pioneers draw on their immense experience as researchers, entrepreneurs, inventors, and consultants, empowering engineers at all levels to succeed with mmWave. They deliver exceptionally clear and useful guidance for newcomers, as well as the first complete desk reference for design experts. The authors explain mmWave signal propagation, mmWave circuit design, antenna designs, communication theory, and current standards (including IEEE 802.15.3c, Wireless HD, and ECMA/WiMedia). They cover comprehensive mmWave wireless design issues, for 60 GHz and other mmWave bands, from channel to antenna to receiver, introducing emerging design techniques that will be invaluable for research engineers in both industry and academia. Topics include Fundamentals: communication theory, channel propagation, circuits, antennas, architectures, capabilities, and applications Digital communication: baseband signal/channel models, modulation, equalization, error control coding, multiple input multiple output (MIMO) principles, and hardware architectures Radio wave propagation characteristics: indoor and outdoor applications Antennas/antenna arrays, including on-chip and in-package antennas, fabrication, and packaging Analog circuit design: mmWave transistors, fabrication, and transceiver design approaches Baseband circuit design: multi–gigabit-per-second, high-fidelity DAC and ADC converters Physical layer: algorithmic choices, design considerations, and impairment solutions; and how to overcome clipping, quantization, and nonlinearity Higher-layer design: beam adaptation protocols, relaying, multimedia transmission, and multiband considerations 60 GHz standardization: IEEE 802.15.3c for WPAN, Wireless HD, ECMA-387, IEEE 802.11ad, Wireless Gigabit Alliance (WiGig)