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The design and layout of a two stage SiGe E-band power amplifier using a stacked transformer for output power combination is presented. In EM-simulations with ADS Momentum, at E-band frequencies, the power combiner consisting of two individual single turn transformers performs significantly better than a single 2:1 transformer with two turns on the secondary side. Imbalances in the stacked transfo
In this paper, we survey Faster-than-Nyquist (FTN) signaling, an extension of ordinary linear modulation in which the usual data bearing pulses are simply sent faster, and consequently are no longer orthogonal. Far from a disadvantage, this innovation can transmit up to twice the bits as ordinary modulation at the same bit energy, spectrum, and error rate. The method is directly applicable to orth
Abstract in UndeterminedAn efficient technique is introduced to reduce mutual coupling between two closely spaced PIFAs for MIMO mobile terminals. The proposed mutual coupling reduction method is based on a T-shape slot impedance transformer and can be applied to both single-band and dual-band PIFAs. For the proposed single-band dual PIFAs, the 10 dB impedance bandwidth covers the 2.4 GHz WLAN ban
Multi-antenna enabled terminal devices are required to comply with the standards for limiting human exposure to electric fields. However, when compared to traditional single-antenna terminals, a comprehensive evaluation of specific absorption rate (SAR) for multi-antenna terminals is impractical. This is because both the power allocation and phase of the electric fields from different antennas are
We study the potential benefits of cooperative multiple-input multiple-output signaling from multiple coherent base stations with one or more mobile stations in an urban macrocellular environment at 2.66 GHz. The analysis uses fully-coherent measurements of the channel from three base stations to a single mobile station equipped with four antennas. The observed channels are used to explore the gai
We design of an efficient channel shortener for nonlinear satellite channels. When the memory of the channel is too large to be taken into account by a full complexity detector, excellent performance can be achieved by properly filtering the received signal followed by a reduced-state detector. This letter derives closed-form expressions for the front-end filter and the target response of the redu
Compact arrays such as multiple antennas on a mobile terminal suffer from low efficiency and high correlation between antenna signals. In the present paper, a simple and rigorous procedure for decoupling two closely coupled antennas with a parasitic scatterer is proposed. The parasitic scatterer, which can be an additional antenna, acts as a shield between two active antenna elements. In contrast
Context: This paper analyses a sub-contractor specification in the mobile handset domain. Objective: The objective is to understand how quality requirements are specified and which types of requirements exist in a requirements specification from industry. Method: The case study is performed in the mobile handset domain, where a requirements specification was analyzed by categorizing and characteri
Geometry-based stochastic channel models (GSCMs) are extended to support multi-link simulations by applying the concept of common clusters. This novel approach aims to control the correlation between different links, inter-link correlation, by adjusting the amount of power simultaneously propagating via the same clusters in the different links. The behavior of common clusters is analyzed based on
This paper presents two class-C CMOS VCOs with a dynamic bias of the core transistors, which maximizes the oscillation amplitude without compromising the robustness of the oscillation start-up, thereby breaking the most severe trade-off in the original class-C topology. An analysis of several different oscillators, starting with the common class-B architecture and arriving to the proposed class-C
Background: Systematic literature reviews and systematic mapping studies are becoming increasingly common in software engineering, and hence it becomes even more important to better understand the reliability of such studies. Objective: This paper presents a study of two systematic mapping studies to evaluate the reliability of mapping studies and point out some challenges related to this type of
The COST 2100 channel model has introduced the concept of common clusters to model multi-link MIMO characteristics. In this paper, a ray launching tool is used to analyze multi-ink propagation properties in an outdoor scenario at 300 MHz. It is shown that in a multi-link propagation scenario there are shared scatterers among the different links, which reflects the physical existence of common clus
This paper presents a low band antenna impedance tuner in 130nm CMOS-SOI technology. It consists of three digitally controlled switched capacitor banks and two off-chip inductors and is intended for use in terminals supporting modern cellular standards like WCDMA and LTE. By using a negative gate bias in the off state, linearity can be improved and maintained. Measurements show an OIP3 exceeding +
This paper presents the co-design of a class-D digitally-controlled oscillator (DCO) and a low-dropout voltage regulator (LDO) generating the supply voltage for the DCO. Despite the high intrinsic supply pushing of the class-D oscillator topology, the LDO noise has only a very marginal impact on the DCO phase noise. The class-D DCO and LDO have been integrated in a 65nm CMOS process without any th
Software systems are becoming increasingly ubiquitous and can be found in devices we use every day from mobile phones to cars. As our reliance on software-based systems increases, our tolerance with software that is ill-fitted to our needs decreases. We expect these devices to function whenever and however we need them to. However, developing these (often) large and complex software systems to mee
Human beings make errors and that is nothing that we can avoid completely. We can however lower the risk of people doing wrong in situations where, for example, medical devices are used. The overall objective of the research presented in this paper is to investigate how usability testing can contribute to software risk management process in the medical device domain. Experience has been collected
In radio communications, a set of links that can transmit in parallel with a tolerable interference is called a compatible set. Finding a compatible set with maximum weighted revenue of the parallel transmissions is an important subproblem in wireless network management. For the subproblem, there are two basic approaches to express the signal to interference plus noise ratio (SINR) within integer
