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The requirement for greater bandwidth in military satellite communication systems has resulted in research for systems that can be used in the EHF band. To support this requirement, the Department of National Defence has sponsored the development of unique Canadian technology under the CANMILSATCOM project that is part of the Canadian commitment to the US Advanced EHF Satcom (AEHF) project. The end...
The development of a very wideband balanced stripline printed dipole array placed above a conducting ground plane, as shown in Fig. 1, is discussed in this paper. A balanced printed dipole has its arms printed on the top and bottom conducting plane of a thin substrate mounted normal to the array ground plane. An integrated matching network forms the centre conductor of the stripline feed. The arms...
This paper presents the design procedure for a 2nd_order two-path Discrete-Time Time-Interleaved (DTTI) ΔΣ modulator from a conventional single-loop 2nd-order Discrete-Time (DT) ΔΣ modulator through the use of time domain equations and time-interleaving concepts [1]. The resulting modulator is free from the delayless feedback path and has only one set of integrators. The delayless feedback path issue...
An open terminated folded inverted-L antenna (FILA) is investigated for the theoretical limitation based on the product of bandwidth and radiation efficiency (Bη product). The FILA consists of two strips without connecting point and two slits on the strips are employed to miniaturize. Aspect ratio of the FILA is chosen as 1 : 2 that the horizontal arm has double the length of the vertical strip. Electrical...
A radar-altimeter system is a critical flight equipment, and must be reliable, and robust. Moreover, its operating limits have to be well known. The characterizations of this kind of product are usually done during expensive instrumented flight, which are not quite reliable in term of reproducibility. For these reasons, the aim of the work presented here is to propose a real time test bed, able to...
For more than two decades, the key objective for synthesis of linear decompressors has been maximizing encoding efficiency. For combinational decompressors, encoding satisfiability is dynamically checked for each specified care bit. By contrast, for sequential linear decompressors (e.g. PRPGs), encoding is performed for each test cube; the resultant static encoding considers that a test cube is encodable...
This paper presents a mechatronics setup based on a reaction wheel inverted pendulum (RWIP). The novelty of this setup is the use of visual feedback (VF) to control a RWIP while the use of a low-cost camera to achieve control was the main motivating factor. The physical parameters that affect the bandwidth were identified from a mathematical model. In turn, relationships between the system bandwidth...
Cost-effective cloud storage services attract users with their convenience; there is a trade-off between the service availability and the usage cost. We develop two cloud provider selection models for cloud storage services to minimize the total cost of usage. The models select multiple cloud providers with considering unavailability to meet the user requirements. The first model, called a user-copy...
Negative impedance converters (NIC) are widely used for impedance matching of electrically-small antennas (ESA). For example, impedance of electrically-small monopole antenna contains high capacitive component and negative capacitance can be used to compensate this. Such negative capacitance can be realized with the use of NIC circuit based on wideband and low noise operational amplifier. Most of...
The most important characteristic of a multipath radio channel is its impulse response. For wideband radio channels in the lower part of the THz-band (Low-THz, 300 GHz–1 THz), the coefficients of this characteristic depend on the frequency, and are determined by the phase changing of the primary and delayed rays, and the variance of the reflection coefficients of electromagnetic waves. In this work...
A multi-resolution technique is presented for sound field recovery based on measurements of one or multiple moving microphones. The interpolation of the spatial samples enables us to set up a system of linear equations that recovers room impulse responses on a virtual uniform grid in space. The spacing of the virtual grid must be very small when directly recovering for the entire bandwidth, thus,...
Due to the massive explosion of social networking and content sharing, it is becoming challenging to transmit a huge amount of multimedia content over wireless mobile networks. The existing paradigm of mobile multimedia sharing has yet to effectively address the energy and bandwidth limitations of wireless devices. Content-Centric Networking (CCN) has been proposed as a possible way to drive the current...
This paper investigates resource allocation algorithms that use limited communication - where the supplier of a resource broadcasts a coordinating signal using one bit of information to users per iteration. Rather than relay anticipated consumption to the supplier, the users locally compute their allocation, while the supplier measures the total resource consumption. Since the users do not compare...
A novel compact microwave absorber with a 10dB absorption level to operate in the wireless communication bands in 1.8 GHz – 2.1 GHz frequency range is investigated. A robust equivalent circuit (EC) model using a new non-resonance constituent parameter extraction technique based on the interpretation of the E- and H-field distribution is discussed. The EC model and the proposed topology is developed...
In the paper, a linear extended state observer (LESO) is designed for ship heading control with wave disturbance via linear active disturbance rejection control (LADRC). In frequency domain, the tracking ability and disturbance rejection capability of LESO has been analyzed in details. Furthermore, the tradeoff between the closed-loop stability and the system requirements, i.e., rudder, input actuator,...
The considerable amount of underutilized spectrum in the unlicensed band has motivated 3GPP to study the introduction of LTE in the ISM band to fulfill its increasing demand for extra bandwidth. This will make LTE and Wi-Fi the main opponents in the ISM band. This paper presents the system performance analysis of MAC for LTE and a comparative study to Wi-Fi. Extensive MAC systems simulations are performed...
Piezoelectric actuator is considered as the main device for the high precision positioning system due to its rapid response, high stiffness and ultra-high resolution. However, the intrinsic hysteresis behavior of piezoelectric actuator can seriously degrade the trajectory-tracking precision. Moreover, the model weights of the Prandtl-Ishlinskii (PI)'s play operator versus velocity are nonlinear which...
This paper examines optimal resource allocation for uncertain communication networks with application to Cyber-Physical Systems (CPS). The aim of the paper is to test the hypothesis that Q-learning can provide an adaptive strategy that reduces or eliminates congestion in a real-time communication network by appropriate channel bandwidth allocation. To demonstrate this, we use a local linear state-space...
CMOS logarithmic amplifiers based on piecewise linear approximation have been usually analyzed and designed by assuming ideal conditions. This paper discusses non-ideal factors in the used components, which play a key role in the performance of high-accuracy logarithmic amplifiers for sensing applications, and shows that the use of simplified mathematical models may lead to wrong conclusions. A gain-mismatch...
Reliable network time measurement tools are important to ensure that monitoring network systems work properly, but their development do not consider security as a concern and, for example, delay attacks could compromise those tools effectiveness. Indeed, nowadays the network time measurement is not always reliable. Some researches do propose to increase network time measurement reliability using Openflow...
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