Investigations into intrachip wireless interconnection for ultra large scale integration technology

A radiation hardened 0.5 /spl mu/m Ultra Large Scale Integration (ULSI) technology was successfully developed to support the full scale production of a 1 Megabit Static Random Access Memory (1M SRAM). This ULSI technology represents the latest in a family of epitaxial bulk silicon CMOS used to produce 64 K SRAM, 256 K SRAM, an enhanced 256 K SRAM, and finally the 1M SRAM. A fast, electrically configurable /spl times/8,/spl times/4,/spl times/1 radiation hardened 1M SRAM has been designed to operate at 3.3 V and is CMOS/TTL compatible. A small cell size of 89 /spl mu/m/sup 2/ was achieved while maintaining a single event upset immunity and a write pulse time of less than 20 ns.

In this paper, a 2mm-long linear on-chip dipole antenna pair on Si substrate is analyzed and simulated to investigate the transmission characteristics using Ansoft's HFSS. By inserting a 0.35mm thick diamond layer between substrate and heat sink, the obtained transmission gain of antenna pair with 1mm separation on 10 Ohm-cm Si substrate increases by 9dB at 20GHz. The effect of the dielectric materials, diamond thickness, substrate resistivity and the separation of an antenna pair on the transmission gain has been investigated. The results indicate that thinner diamond layer along with high resistivity substrate is preferred. A modified propagation model involving a diamond layer is also evaluated to make antenna performance predictable in real wireless interconnection systems.

A methodology has been developed for fast process development and integration of multilevel metallization systems for ultra large scale integration technology. This methodology defines a set of primitive processes, which are then arranged in the required configuration to build or develop multilevel metallization systems. Each primitive process will have a predictive model and process control and calibration strategy including a set of test structures. This paper will describe how the methodology defined above has been applied to develop contacts and vias for multilevel metallization.

Many device scientists believe that current Ultra Large Scale Integration (ULSI) technology will face technical and economic difficulties in further miniaturization. It has been proposed that 1-dimensional (1-D) transistors with connecting wires and three-dimensionally stacked structures may replace current field effect transistors with planar integration structures. We propose a new scheme to fabricate and integrate 1-D active devices. As a first step, we show the way to form 1-D wires with spatially variable electronic structures and the way to characterize them.

This paper demonstrates the comparison between two on-chip antennas, circular microstrip patch antenna (CMPA), and cylindrical dielectric resonator antenna (CDRA), planned for operation at 60 GHz and integrated into 0.18-µm CMOS integrated circuits. The antennas are fed with similar feeding networks. The bandwidth for a return loss below −10 dB is 17.9 % for CMPA and 21 % for CDRA. The simulated radiation patterns of both antennas exhibit similar properties. The gain of the CDRA is 2.2 dB higher than CMPA. Likewise, the results show that the radiation efficiency of CDRA is significantly higher than that of the CMPA at 60 GHz. A comparative study on the transmission gain for wireless interconnections using CMPA and CDRA in the cases of intra- and inter-chip interconnections is investigated. Transmission gain proves the superiority of CDRA compared to CMPA. The proton implantation technique is used to improve the transmission gain. The silicon substrate resistivity is increased from 10 Ω-cm up to 10 MΩ-cm.

The improvement of maritime radio links often requires an increase of emitted power or receiver sensitivity. Another way is to replace the poor antenna gains of traditional surface ship whips by novel antenna structures with directive properties. However, ship motions, especially when launches are involved, may affect the radio link quality. Therefore, a tool for modelling the impact of ship motions on such antenna structures was developed. It helps the specification of antenna radiating parameters and improves the radio link performance evaluation. This tool includes a deterministic two-ray model for radio-wave propagation over the sea surface. The geometrical 3D engine for ship motions has the advantage to be compatible with any propagation model and antenna structure.

This paper introduces a new low cost, robust miniaturized microstrip antenna inspired with metamaterial split ring resonator structure (SRR). Because of metamaterials property there has been considerable reduction in size. The overall antenna structure is phi shaped, which is the same as having two SRRs back to back. The scattering matrix characteristics of this phi shaped antenna (PSA) have been investigated using the EM solver Ansoft HFSS. Excellent performance in terms of size and radiation pattern is achieved. These types of antennas are very useful for applications where space of equipment is a constraint. Radiation pattern of the antenna is dough nut shaped, nearly omni-directional. This type of antenna is useful for the applications like sensors for ground penetration radar, sensors for detection of malignant tissues in skin cancer patients and other handheld portable wireless equipments.

A 47.6 to 58.1 GHz wireless interconnect implemented in standard CMOS (i.e., complementary metal oxide semiconductor) process is designed and simulated. The wireless interconnect consists of a phase-locked loop (PLL)-based frequency synthesizer and a wideband power amplifier. The power amplifier has been designed by four branches of differential amplification stage, while their powers are combined coherently. To enhance the power-added efficiency (PAE) during power backoff, the power amplifier also adopts a dynamic power control scheme. The PLL-based frequency synthesizer is realized through a broadband millimeter-wave phase-locked loop where its input clock is provided by a radio-frequency delay-locked loop. The PLL-based frequency synthesizer has employed a quadrature-phase mixer phase detector for mutual ripple compensation without degrading the PLL phase noise. Simulation results have shown that the introduced power amplifier realizes a saturated output power <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$P_{\text {sat }}$</tex> of 15.7 dBm with 12.8 % PAE (i.e., power-added efficiency). Moreover, the wireless link can recover non-return-to-zero (NRZ) data rate to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$11.2 ~\text{Gb} / \mathrm{s}$</tex>.

Various types of antennas and transmission media for electromagnetic waves (coax cable, waveguides, etc.) exhibit symmetry around an axis of rotation and hence called bodies of revolution. By analytically extracting the known periodic behavior of the fields in the azimuth, the fields everywhere may be found by solving Maxwell's equations in a single two dimension plane. This body of revolution (BOR) approach has been used in the past with other numerical techniques for solving electromagnetic problems. Although the use of BOR approach with the finite difference time domain (FDTD) technique has already been reported, this paper presents an advanced integration of the FDTD-BOR with the perfectly matched layer absorbing boundary condition. This implementation significantly reduces the undesired reflection of outgoing waves due to the mesh truncation for a wide range of frequencies. Good agreement with published computed and measured data are obtained with the developed FDTD-BOR-PML technique for dielectric resonators and microstrip antennas. The developed algorithm is used for the analysis and design of new types of axi-symmetric antennas for personal wireless communications.

High Tc superconducting (SC) active antennas, which are new types of antennas with a use of active properties of high Tc superconductors, are investigated. The SC active antennas were made from Y-type thin films, which were prepared with magnetron (sputtering) method. As for detections of electromagnetic waves ( f=9.55GHz, f=50.4GHz and 474THz), the sensitivities of the SC active antennas were found to depend on polarizations of radiated electromagnetic waves, applied currents, the annealing temperature, the strength of electromagnetic waves and structures of antennas et al.

Heterogeneous multichip architectures have gained significant interest in high-performance computing clusters to cater to a wide range of applications. In particular, heterogeneous systems with multiple multicore CPUs, GPUs, and memory have become common to meet application requirements. The shared resources like interconnection network in such systems pose significant challenges due to the diverse traffic requirements of CPUs and GPUs. Especially, the performance and energy consumption of inter-chip communication have remained a major bottleneck due to limitations imposed by off-chip wired links. To overcome these challenges, we propose a wireless interconnection network to provide energy-efficient, high-performance communication in heterogeneous multi-chip systems. Interference-free communication between GPUs and memory modules is achieved through directional wireless links, while omnidirectional wireless interfaces connect cores in the CPUs with other components in the system. Besides providing low-energy, high-bandwidth inter-chip communication, the wireless interconnection scales efficiently with system size to provide high performance across multiple chips. The proposed inter-chip wireless interconnection is evaluated on two system sizes with multiple CPU and multiple GPU chips, along with main memory modules. On a system with 4 CPU and 4 GPU chips, application runtime is sped up by 3.94×, packet energy is reduced by 94.4%, and packet latency is reduced by 58.34% as compared to baseline system with wired inter-chip interconnection.

The extensive demand for high-speed communication and connectivity has triggered the need for research in fifth-generation (5G) of mobile communication. The 5G evolution will not be limited to only mobile phones but also provide seamless connectivity through the internet of Things (IoT) in services like smart cities, smart homes etc. The clear intention of the 5G technology is to provide a vast capacity of network, a higher speed of multiple Gigabits per second, and enhanced dependability with negligible latency and stable radiation. This goal will not be possible without an efficient antenna structure. Numerous 5G antenna designs have been put forth so far by various researchers, but a thorough analysis of the various types of antennas and the techniques of 5G used to improve their performance is required to select an appropriate design for a particular application. The most recent research on the various antenna types and performance improvement methods for 5G technology is presented in this review study. This study is an effort to comprehensively examine the various types of 5G antenna structures, their performance optimization methodologies, comparison, and potential future advancements.

Sensors such as phased array radars play a crucial role in public safety. They are unavoidable for surveillance, threat identification and post-disaster management. However, different scenarios impose immensely diverse requirements for these systems. Phased array systems occupy a large space. In addition, if different antenna systems are needed for each function, the space required can be considerably large. For transportable platforms, such as ships and aircrafts, space and weight are critical parameters. Therefore, reconfigurable multi-band antennas are very attractive solutions for future multi-function sensor systems. Within this research work three different approaches are investigated to realize antennas for reconfigurable phased arrays. Wideband antenna designs constitute the first approach. Integrating this type of antennas with frequency selective filters provide the opportunity for fine tuning within one radar band. The wideband operation of the antenna is achieved by the blind-via feeding section and the quasi electric-magnetic radiating structure. The second approach involves the design of an antenna element with p-I-n diode switches. The switches are used to alter the antenna structure and thereby the operating frequency. Measured results verified the frequency reconfigurable capability of the antenna within L/S radar bands with frequency ratio more than 2:1. The planar structure, the back feeding mechanism, the compact size and the simple bias network made the proposed antenna suitable for array applications. The large frequency ratio and its usability in phased array applications made the design novel. Furthermore, for these frequency reconfigurable elements, a unique multi-scale array structure is introduced which can assure wide angle scanning for both frequency bands. The advantage of this novel array configuration is twofold: reduce the mutual couplings in the lower band, and increase the scanning volume for the higher band. A planar array demonstrator validated the proposed concept. In the third approach the operational band of an antenna is tuned by variable-impedance matching. In this study, the standard 50 ? matching is avoided and many advantages of variable-impedance matching are demonstrated. First, the principle is verified by tuning the frequency band of a microstrip antenna by an input-impedance tuneable CMOS RF-frontend. In the second design a novel dual-band E-slot antenna, with 2.5:1 frequency ratio, was designed. By changing the input-impedance the operating frequency of the antenna can be switched from L- to S-band. Variable-impedance matching provides few other advantages to phased array antennas. A scan-angle dependent impedance matching will assure low reflection coefficients for the entire scanning volume. On the other hand, it will reduce interfering and jamming signals coming from adjacent angles. The outcomes of this research work have led to solid understanding of how we can realize frequency reconfigurable antennas for adaptive phased arrays. The results will be particularly valuable in developing future narrow or wide beam radar systems with frequency reconfiguration and angular filtering capabilities.

With the constant increase in communication requirements in modern society, the number and type of antennas on communication platforms have been increasing at an accelerating rate. This has led to a continuous increase in platform volume and weight, and the electromagnetic environment of antenna operating has increasingly worsened, seriously restricting the further development of communication systems. As a new communication system antenna type, a reconfigurable microstrip antenna can reconstruct operating frequencies, beam directions, etc., by changing the antenna structure to provide the good multifunction characteristics of a single antenna, avoiding the electromagnetic compatibility issues caused by numerous system antennas. At present, most of the research on reconfigurable antennas judges the influence of structural characteristics on electromagnetic characteristics by simulation, which has imposed restrictions on their development and application. Therefore, a reconfigurable antenna with a resonant frequency of 8.66 GHz and 15.26 GHz and a reconfigurable antenna with maximum radiation directions of 36.2° and −36.5° are designed in this paper, and the electromechanical coupling theory of the reconfigurable antennas is studied. The resonance frequency coupling model and the pattern function coupling model considering the structural deformation of a reconfigurable microstrip antenna are established. Within the applicable range of antenna structural parameters, the relative error between the resonance frequency coupling model and the pattern function coupling model is less than 5%, which meets practical engineering application requirements. Finally, the method is shown by experimentation to verify the accuracy and validity of the proposed electromechanical coupling model.

The recently introduced quantum particle swarm optimization (QPSO) algorithm is employed to find infinitesimal dipole models (IDM) for antennas with known near-fields (measured or computed). The IDM can predict accurately both the near-fields and the far- fields of the antenna. A theory is developed to explain the mechanism behind the IDM using the multipole expansion method. The IDM obtained from single frequency solutions is extrapolated over a frequency range around the design frequency. The method is demonstrated by analyzing conductingand dielectric- type antennas. A calibration procedure is proposed to systematically implement infinitesimal dipoles within existing MOM codes. The interaction of the IDM with passive and active objects is studied through several examples. The IDM proved to predict the interaction efficiently. A closed-form expression for the mutual admittance between similar or dissimilar antennas, with arbitrary orientations and/or locations, is derived using the reaction theorem.