SPDT discrete switch design using switchable SIW resonators for millimeter wave MIMO transceiver

A single pole double throw (SPDT) discrete switch design using switchable substrate integrated waveguide (SIW) resonators is proposed in this paper. It was designed for the millimeter wave multiple input multiple output (MIMO) transceiver. An example application is for 5G communication in 26 GHz band. High isolation between transmitter and receiver (in the transceiver) is needed in SPDT switch design to minimize any high radio frequency (RF) power leakage in the receiver. Therefore, the use of switchable SIW resonators can achieve higher isolation if compared to the conventional series SPDT switch, where the isolation of the proposed SPDT is depend on the bandstop response of the SIW resonators. The switchable SIW resonators can be switched between allpass and bandstop responses to allow the operation between transmit and receive modes. As a result, the simulation and measurement showed that the proposed SPDT switch produced an isolation higher than 25 dB from 24.25 to 27.5 GHz compared to the conventional design.

Investigation and Suppression of RF Leakage Power in Front End Wireless Devices

In this modern Communication Wireless System, Frequency Division Duplex (FDD) is mostly used. Duplex is a device to separate Transmitter and Receiver signals. Transmitter or Power leakage causes from limited isolation performance of the duplexer. Various Techniques of Modulation using Orthogonal Frequency Division Multiplexing (OFDM) provided better solution to cancel this leakage. The OFDM provides high spectral efficiency, lower multi-path distortion and to eliminate inter symbol interference (ISI). Fast Fourier Transform implemented modulation and demodulation functions more efficiently. Using simulation result of the various parameters are analysed. In addition, Comparison of the table between Bit rate error value, Signal strength throughput, Power consumption and Mean square error values obtained in the OFDM systems.

Analysis on Influences of Intra-Couplings in a MISO Magnetic Beamforming Wireless Power Transfer System

Magnetic beamforming techniques can enhance the power transfer efficiency using focused magnetic fields by the multiple transmitters to the receivers. However, the intra-couplings that cause power leakage and phase distortion among the arrayed coils inevitably occur due to the deployment of coils having strong couplings between each other. Here, we analyze the adverse influences of intra-couplings and present the advantages of magnetically independent transmitters for multiple-inputs and single-output (MISO) WPT. The independent coil array can achieve focused magnetic fields by simply adjusting the amplitude of the transmitter voltage source without phase adjustment. The system also can eliminate the reactive power with the independent coil array to efficiently use the supplying power from the source. The analytical studies are verified by numerical and circuit simulation and experiments. Our analysis can be generalized to the MISO-WPT with an arbitrary number of transmitters. It can provide insight into designing and implementing the MISO-WPT applying magnetic beamforming.

Search-Space Reduction for S-Boxes Resilient to Power Attacks

The search of bijective n×n S-boxes resilient to power attacks in the space of dimension (2n)! is a controversial topic in the cryptology community nowadays. This paper proposes partitioning the space of (2n)! S-boxes into equivalence classes using the hypothetical power leakage according to the Hamming weights model, which ensures a homogeneous theoretical resistance within the class against power attacks. We developed a fast algorithm to generate these S-boxes by class. It was mathematically demonstrated that the theoretical metric confusion coefficient variance takes constant values within each class. A new search strategy—jumping over the class space—is justified to find S-boxes with high confusion coefficient variance in the space partitioned by Hamming weight classes. In addition, a decision criterion is proposed to move quickly between or within classes. The number of classes and the number of S-boxes within each class are calculated, showing that, as n increases, the class space dimension is an ever-smaller fraction of the space of S-boxes, which significantly reduces the space of search of S-boxes resilient to power attacks, when the search is performed from class to class.

A Study of Different SRAM Cell Designs

Presently, huge advancements are being witnessed in the electronics sector like AR, AI, driverless cars, smart homes, portable devices like mobile phones, etc. that requires the improvement of memory technology for efficient working. Memory plays a major role in the present scenario of improvements and growth. Out of different forms of memory devices, the most popular and presently used type of form is the semiconductor MOS memory, specifically SRAM (Static Random-Access Memory) that plays a very important role in the microprocessor domain as it covers a large portion of the chip. But with the increased scale of integration, leakage power, leakage current, and delay becomes a problem in the designing of an SRAM cell. This paper is a review of SRAM cells that have been proposed in the past for achieving improvement in SRAM cell parameters like power consumption, delay, leakage current, read and write stability, better cell operations, etc.

Modal coupling and crosstalk due to turbulence and divergence on free space THz links using multiple orbital angular momentum beams

Orbital-angular-momentum (OAM) multiplexing has been utilized to increase the channel capacity in both millimeter-wave and optical domains. Terahertz (THz) wireless communication is attracting increasing attention due to its broadband spectral resources. Thus, it might be valuable to explore the system performance of THz OAM links to further increase the channel capacity. In this paper, we study through simulations the fundamental system-degrading effects when using multiple OAM beams in THz communications links under atmospheric turbulence. We simulate and analyze the effects of divergence, turbulence, limited-size aperture, and misalignment on the signal power and crosstalk of THz OAM links. We find through simulations that the system-degrading effects are different in two scenarios with atmosphere turbulence: (a) when we consider the same strength of phasefront distortion, faster divergence (i.e., lower frequency; smaller beam waist) leads to higher power leakage from the transmitted mode to neighbouring modes; and (b) however, when we consider the same atmospheric turbulence, the divergence effect tends to affect the power leakage much less, and the power leakage increases as the frequency, beam waist, or OAM order increases. Simulation results show that: (i) the crosstalk to the neighbouring mode remains < − 15 dB for a 1-km link under calm weather, when we transmit OAM + 4 at 0.5 THz with a beam waist of 1 m; (ii) for the 3-OAM-multiplexed THz links, the signal-to-interference ratio (SIR) increases by ~ 5–7 dB if the mode spacing increases by 1, and SIR decreases with the multiplexed mode number; and (iii) limited aperture size and misalignment lead to power leakage to other modes under calm weather, while it tends to be unobtrusive under bad weather.

Constant Envelope Multiplexing of Multi-Carrier DSSS Signals Considering Sub-Carrier Frequency Constraint

With the development of global navigation satellite systems (GNSS), multiple signals modulated on different sub-carriers are needed to provide various services and to ensure compatibility with previous signals. As an effective method to provide diversified signals without introducing the nonlinear distortion of High Power Amplifier (HPA), the multi-carrier constant envelope multiplexing is widely used in satellite navigation systems. However, the previous method does not consider the influence of sub-carrier frequency constraint on the multiplexing signal, which may lead to signal power leakage. By determining the signal states probability according to the sub-carrier frequency constraint and solving the orthogonal bases according to the homogeneous equations, this article proposed multi-carrier constant envelope multiplexing methods based on probability and homogeneous equations. The analysis results show that the methods can multiplex multi-carrier signals without power leakage, thereby reducing the impact on signal ranging performance. Meanwhile, the methods could reduce the computation complexity. In the case of three different carriers multiplexing, the number of optimization equations is reduced by nearly 66%.

Side-Channel Analysis of the Xilinx Zynq UltraScale+ Encryption Engine

The Xilinx Zynq UltraScale+ (ZU+) is a powerful and flexible System-on- Chip (SoC) computing platform for next generation applications such as autonomous driving or industrial Internet-of-Things (IoT) based on 16 nm production technology. The devices are equipped with a secure boot mechanism in order to provide confidentiality, integrity, and authenticity of the configuration files that are loaded during power-up. This includes a dedicated encryption engine which features a protocol-based countermeasure against passive Side-Channel Attacks (SCAs) called key rolling. The mechanism ensures that the same key is used only for a certain number of data blocks that has to be defined by the user. However, a suitable choice for the key rolling parameter depends on the power leakage behavior of the chip and is not published by the manufacturer. To close this gap, this paper presents the first publicly known side-channel analysis of the ZU+ encryption unit. We conduct a black-box reverse engineering of the internal hardware architecture of the encryption engine using Electromagnetic (EM) measurements from a decoupling capacitor of the power supply. Then, we illustrate a sophisticated methodology that involves the first five rounds of an AES encryption to attack the 256-bit secret key. We apply the elaborated attack strategy using several new Deep Learning (DL)-based evaluation methods for cryptographic implementations. Even though we are unable to recover all bytes of the secret key, the experimental results still allow us to provide concrete recommendations for the key rolling parameter under realistic conditions. This eventually helps to configure the secure boot mechanism of the ZU+ and similar devices appropriately.

Broadband Transition from Rectangular Waveguide to Groove Gap Waveguide for mm-Wave Contactless Connections

In this paper, the authors present a broadband transition from the standard WR-10 rectangular waveguide (RW) to a groove gap waveguide (GGW) in the W-band. The transition structure is based on electromagnetic band gap (EBG) technology where two EBG units are used, which are responsible for the transition and forming the transmission line. Metal pins in the E-plane together with the back surface of the transmission line create a forbidden band, which prevents power leakage between the connecting parts. Small air gaps will not harm the transition performance according to the simulation, which means it has a better tolerance of manufacturing and assembly errors and, thus, has advantages for mm-wave contactless connections. A back-to-back transition prototype was designed, fabricated and measured. The length of the GGW is 39.6 mm. The measured |S11| is better than −13 dB and the measured |S21| is better than −0.6 dB over 76.4–109.1 GHz, covering a bandwidth of 35.3%.