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In this paper, the performance of a millimeter wave (mmWave) Multi-Input Multi-Output (MIMO) system is investigated using low complexity receivers. The receivers include linear Maximum Ratio Combiner (MRC), linear Zero Forcing (ZF) receiver, or linear Minimum Mean-Square Error (MMSE) receiver, in addition to ZF Vertical Bell Laboratories Layered Space-Time (ZF-VBLAST). A MIMO channel model based on a ray-tracing approach and the uniform theory of diffraction has been used. The effect of increasing the number of rays used in the channel model is investigated on the performance of all receivers. For all the scenarios, it has been found out that the ZF-VBLAST structure provides the best symbol-error-rate performance followed by the linear MMSE, then the ZF receiver, and finally the MRC receiver. The trade-off paid for achieving better performance is the increased receiver complexity. The system's performance is compared under a conventional statistical channel model and a ray-based channel model for a fifth-generation (5G) mobile radio system. It is noted that these models do not accurately characterize the specific environment, hence resulting in an optimistic estimate of the system performance. Finally, the ray-tracing channel model is modified to account for the impact of the presence of trees within the environment. The results show that the performance degradation due to the presence of trees is between 2 to 5 dB for ZF and MMSE receivers, respectively. [ABSTRACT FROM AUTHOR]

In this paper, the throughput maximization of millimeter-wave (mm-Wave) ultradense networks (UDN) using dynamic spectrum sharing (DSS) is considered. Most of the existing works only allow temporal-domain access and admit at most one user at each time slot, resulting in significant underutilization of spectrum resource, which will be less attractive to mm-wave UDN applications. A generalized temporal-spatial sharing scheme is proposed in this paper for UDN by exploiting the location information of incumbent devices, where multiple users are allowed to access each channel simultaneously via spatial separations. For distributed applications, the global information exchange among secondary users (SU) tends to be impractical, given the unaffordable signaling overhead and latency. Thus, a noncooperative game with fine-grained two-dimensional reuse is formulated, which leads to a more efficient access strategy. It is then proved to be an ordinary potential game (OPG), which guarantees the existence of the strategy Nash equilibrium (NE). Finally, an improved decentralized reinforcement learning algorithm is designed, with which SUs can learn from wireless environments and adapt toward an NE point, relying on the individual observation and the historical action reward (rather than the global information exchanging). The convergence efficiency of the new scheme is also rigorously proved. Numerical simulations are provided to validate the performances of the proposed schemes. [ABSTRACT FROM AUTHOR]

ABSTRACT Based on the microwave integrated circuit and millimeter wave integrated circuit technology, a pair of TX and RX front-ends operating at 60 GHz are designed and fabricated, with all the functional modules optimized and integrated from the aspect of system application. The integrated front-end system fulfills the design requirements and provides technical and devices support for its application in short distance wireless communication. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2894-2897, 2016 [ABSTRACT FROM AUTHOR]

Millimeter wave (mmWave) communication provides high data rates thanks to large arrays at the transmitter and receiver, coupled with large bandwidth channels. Exploiting the arrays is challenging due to the need to configure precoding at the transmitter based on the large frequency selective channel. In this paper, we exploit the power iteration principle and propose a robust analog precoding training algorithm that can be applied in both frequency division duplex transmission systems and time division duplex transmission systems with or without RF calibration. We further analyze the convergence of the proposed algorithm and show how it converges to the singular value decomposition optimality exponentially. We propose null space projection on top of the power iteration to form multiple orthogonal beams at the transmitter and receiver. Strongest tap selection with proper energy pruning is used to collect as much precoding gain as possible from a frequency selective fading channel. The exponential effective SINR mapping performance is evaluated and demonstrates that the overall approach works smoothly. Numerical simulation results demonstrate algorithm robustness and the algorithm works not only for the simplified mmWave directional channels, but also for more general rich scattering channels. [ABSTRACT FROM PUBLISHER]

This paper presents the design of a two stage CMOS low noise amplifier implemented in 45 nm technology. The designed amplifier operates at 60 GHz. The amplifier uses common source inductively degenerated cascode structure for simultaneous improvement in noise figure and stability factor. The gain of the amplifier is 15.2 dB at 60 GHz and provides a 3-dB bandwidth of 11 GHz, noise figure of 6.03 dB, input 1-dB compression point (P1dB) -15.50 dBm, and an input third order intercept point -7.3 dBm were achieved while dissipating a power of 29.7 mW from a power supply of 1.2 V. Design is based on the maximum transconductance available with minimum value of CMOS width. Resistive and capacitive feedback in millimeter wave frequency range adds stability and gain bandwidth to the output of LNA, instead of using feedback at both of the stages it is directly employed between the drain of second stage and gate of the first stage of common source structure. The simulation was done in Cadence virtuoso gpdk-45 nm software package. [ABSTRACT FROM AUTHOR]

The turnstile junction exhibits very low cross-polarization leakage and is suitable for low-noise millimeter-wave receivers. For use in a cryogenic receiver, it is best if the orthomode transducer (OMT) is implemented in waveguide, contains no additional assembly features, and may be directly machined. However, machined OMTs are prone to sharp signal drop-outs that are costly to overall performance since they show up directly as spikes in receiver noise. We explore the various factors contributing to this degradation and discuss how the current design mitigates each cause. Final performance is demonstrated at cryogenic temperatures. [ABSTRACT FROM AUTHOR]

The limited availability of analog-to-digital converters with high enough speed and dynamic range makes conventional heterodyne receivers still a reasonable solution for millimeter wave work when a wide frequency tuning range is desired. These basically well-known arrangements from the microwave bands may show surprising phenomena if the features of individual millimeter building blocks are not carefully analyzed. LNA gain below the frequency range of interest can be 10-20 dB more than expected which could severely impair the system noise performance after downconversion. Local oscillator tuning sensitivity above 1000 MHz/V, partly based on almost mandatory multiplication, together with very large tuning speed easily cause stability problems. Particularly active multipliers have often less than 20 dB rejection of fundamental frequency and unwanted harmonics output, which together with mixer LO/IF feed through can completely desensitize the front-end. An improperly matched mixer IF port may confuse even an experienced designer by phantom responses. Finally, modern logarithmic detectors chips can unexpectedly waste more than 10 dB of receiver sensitivity. [ABSTRACT FROM AUTHOR]

The Atacama Large Millimeter/submillimeter (ALMA) Array Front End (FE) system is the first element in a complex chain of signal receiving, conversion, processing and recording. 70 Front Ends will be required for the project. The Front End is designed to receive signals in ten different frequency bands. In the initial phase of operations, the antennas will be fully equipped with six bands. These are Band 3 (84-116 GHz), Band 4 (125-163 GHz), Band 6 (211-275 GHz), Band 7 (275-373 GHz), Band 8 (385-500 GHz) and Band 9 (602-720 GHz). It is planned to equip the antennas with the missing bands at a later stage of ALMA operations, with a few Band 5 (163-211 GHz) and Band 10 (787-950 GHz) receivers in use before the end of the construction project. The ALMA Front End is far superior to any existing receiver systems; spin-offs of the ALMA prototypes are leading to improved sensitivities in existing millimeter and submillimeter observatories. The Front End units are comprised of numerous elements, produced at different locations in Europe, North America and East Asia and are integrated at several Front End integration centers (FEIC) to insure timely delivery of all the units to Chile. The North American FEIC (NA FEIC) is at the National Radio Astronomy Observatory facility in Charlottesville, Virginia, USA. This paper describes the design and performance of the test set used at the NA FEIC to check the performance of the Front Ends, following integration and prior to shipment to Chile. [ABSTRACT FROM AUTHOR]

The LFI (Low Frequency Instruments) receivers in the coming Planck satellite are of continuous comparison type and use low noise amplifiers based on high electron mobility transistors manufactured from indium phosphide substrate (INP-HEMT-MMIC-LNAs). This article describes the 1/f-noise tests and the associated test system for the 70 GHz demonstrator receiver, which can either use single or dual channel phase switcher methods. The 1/f knee frequency is shown to depend on the calculation method of the r-value. A minimum 1/f knee frequency around 10 mHz has been achieved with full two channel foxtrot and individually adopted r-values for each phase states while a straightforward single phase technology cannot go below 40 mHz [ABSTRACT FROM PUBLISHER]

In this letter, we present results of fully integrated 90–130 GHz receiver based on 100 nm mHEMT technology. The receiver contains a low noise amplifier (LNA), mixer and LO multiplier chain integrated into a single monolithic microwave integrated circuit (MMIC). The circuit is packaged into a waveguide block, characterized and compared to on-wafer measurements. Waveguide to microstrip transitions are used to interface the MMIC to the waveguide. A breakout LNA circuit is also packaged, and its performance is compared to the receiver. The LNA noise was characterized on a wafer and after packaging. The packaged module is measured at both room and cryogenic temperatures, NF of 3.7 dB is measured at 300 K and 0.9 dB at 20 K. [ABSTRACT FROM PUBLISHER]

We report on the design and construction of an 8×8 bolometer array designed to operate at 90 GHz on the new 100 m Green Bank Telescope (GBT). The bolometers are Transition Edge Superconducting (TES) detectors read out using a SQUID multiplexing system. The receiver will be one of the first astronomical instruments to use such detectors. To cool the detectors, we have developed 3He and 4He sorption refrigerators that cycle from a two-stage pulse-tube cryocooler. The system has been demonstrated to be robust, to be capable of cycling autonomously, and to provide 15 μW of cooling below 286 mK with a hold time over 70 h. Although modest in size, a combination of the size of GBT and the low noise of the TES detectors will make our receiver one of the most sensitive of its kind. [Copyright &y& Elsevier]

A K-band on-off keying (OOK) receiver implemented in tsmc™ 90 nm CMOS process is proposed. The proposed OOK receiver consists of a two-stage wideband low-noise amplifier, a single-to-differential envelop detector with RC lowpass filter and a 62.6 dB three-stage variable gain amplifier and DC offset compensation circuit. The OOK receiver achieved a sensitivity of -47.6 dBm at 600 Mbit/s data rate under a pseudo-random binary sequence 29-1 pattern. The receiver consumes a low power of 9.5 mW, which minimum average power is only 15.86 nW at the input power of -47.6 dBm. The chip area including test pads is 1 × 0.81 mm². [ABSTRACT FROM AUTHOR]

This paper proposes a novel packaging solution which integrates micro-machined 3D horn antennas with millimeter-wave and THz tranceivers. This packaging solution is shown to be a valid competitor to existing technologies like metallic split-block waveguides and low temperature cofired ceramics. Three different fabrication methods based on two-photon lithography are presented to form the horn antennas. The first uses two-photon lithography to form the bulk of the antenna. This structure is then metalised through physical vapor deposition (PVD) and copper plating. The second fabrication method makes use of a soft polydimethylsiloxane (PDMS) mold to easily replicate structures and the third method forms the horn antenna through electroforming. A prototype is accurately positioned on top of a 400 GHz 28 nm CMOS transmitter and glued in place with epoxy, thus providing a fully packaged solution. Measurement results show a 12 dB increase in the antenna gain when using the packaged solution. The fabrication processes are not limited to horn antennas alone and can be used to form a wide range of mm-sized metal components. [ABSTRACT FROM AUTHOR]