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In this paper we assess the mechanical and thermal performance of a load-bearing spiral antenna fabricated using conductive textile threads (E-threads). This textile spiral exhibits a neariy 10:1 bandwidth (0.3–3GHz) with circularly polarized gain of 6dBi across the 1–3GHz band. Such performance is unique for textiles and flexible surfaces. Mechanical tests for the spiral showed no appreciable changes...
A design of electrically small multi-turn loop antennas for on-the-move man-pack high frequency near vertical incidence skywave communications is discussed. Parameters such as bandwidth, gain, and RF exposure are considered for loops with 1, 2 and 3 turns as well as with a 2-arm loop configuration. For the initial study, all loop diameters are set at 1 m. It is shown that more turns on a loop antenna...
A circularly symmetric high impedance surface is used as ground plane for spiral antennas. It is shown through simulations that a circular high impedance surface exhibits a wider operational bandwidth when used as ground plane for this type of radiators compared to loop antennas.
We investigate multi-port ladder impedance matching (MLM) for enhancing the capacity of compact MIMO communication systems. MLM builds upon single-port matching (SPM) techniques by incorporating an additional reactance that connects adjacent antenna ports together and promises enhanced performance while maintaining good bandwidth. We demonstrate numerically for a 5-element compact MIMO system that...
Implantable medical devices (IMDs) is recently receiving significant attention in patient care and management including medical diagnosis and treatment. A miniaturized 19.9mm × 21.95mm (Patch Area) dual-band body implantable antenna is presented for MICS band (402–405 MHz) and ISM band (2.36–2.4 GHz) applications.
A thin and ultra-wideband metamaterial absorber comprising single-dielectric substrate is investigated in this paper. The proposed structure contains a ground plane and relies on the bianisotropic properties of the unit cells forming the absorbing layer. This structure is realized as an array of periodic conducting circular loops and L-shaped strips with lumped resistors. Lumped resistors are used...
This paper investigates the effects of background traffic streams in the packet inter-arrival rates of an LTE traffic stream, when these streams are transported over the same Ethernet fronthaul network. Contention of background traffic with LTE traffic can occur in a Cloud-RAN that is transporting traffic streams originating from Constant Bit-Rate (CBR) sources such as the Common Public Radio Interface...
A time-modulated antenna array (TMAA) provides similar beamforming capability as a phased antenna array. The main difference is generation of sideband components. Such components limit allowable bandwidth of digitally modulated signals transmitted over the TMAA. Nevertheless, the time-modulation allows spatial filtration of mutually interfering signals. In this paper two experimental studies are presented...
In the paper we presents a dual-open-slot antenna, with a overall size of 50 × 13 × 3.5 mm3. The antenna consists of a long-open-slot and a short-open-slot. The tail of the long-slot is bent for compact size. The dual-slot antenna is feed by an L-shaped microstrip line. The long-slot used in the 2.4GHz mode and short slot excitation in 5.2 GHz mode. The open slots are excited through the L-shaped...
One of the challenges for the 5th generation of mobile cellular networks is the energy consumption efficiency. In this paper we propose an optimization algorithm that maximizes the energy efficiency. We apply the proposed optimization algorithm for both indoor- and outdoor users. The energy efficiency optimization is carried under various network conditions such as maximizing the bit rate, minimizing...
Millimeter-wave (mmWave) massive MIMO used for access and backhaul in ultra-dense network (UDN) has been considered as the promising 5G technique. We consider such an heterogeneous network (HetNet) that ultra-dense small base stations (BSs) exploit mmWave massive MIMO for access and backhaul, while macrocell BS provides the control service with low frequency band. However, the channel estimation for...
Technologies for millimeter wave (mmWave) communication are at the forefront of investigations in both industry and academia, as the mmWave band offers the promise of orders of magnitude additional available bandwidths to what has already been allocated to cellular networks. The much larger number of antennas that can be supported in a small footprint at mmWave bands can be leveraged to harvest massive-MIMO...
This paper shows a comparison between two population-based algorithms: Particle Swarm Optimization and Social Network Optimization. This comparison is related to the operators of these algorithms, their performance on standard benchmark functions and, finally, on the optimization of a dual-layer reflectarray antenna.
We present a polarization- reconfigurable multislot antenna with four switchable linear polarizations (as 0°, ± 45° and 90°) for implant communications. The design is based on four bow-tie shaped slots acting as radiators etched on a circular metallization plane with 45° rotated sequential arrangements. RF switches based on PIN diodes are connected across each slot in order to modify the radiators...
This paper presents a preliminary study of channel characteristics in the frequency ranges of 75 – 110 GHz and 270 – 320 GHz. We select a small office as a typical application scenario and carried out extensive measurements with the Vector Network Analyzer (VNA) and frequency extension units in the room. A ray tracing simulator is applied for reproduction of the measurement results and a good match...
We study the energy radiated from a circular loop antenna which is located on the surface of an axially magnetized plasma column in free space and excited by a given wideband pulsed voltage. The radiated energy and its distribution over the frequency and spatial spectra of the excited waves are derived and analyzed for some cases of interest.
A circular polarization-reconfigurable (CPR) monopole antenna for Global Navigation Satellite System (GNSS) applications is proposed. The CPR antenna consists of two meandered monopoles denoted as MP1 and MP2, a switchable feeding network, and a metasurface (MS) using dual-cap mushroom-like unit cells. The two monopoles have tapered shapes for better matching and wider impedance bandwidth. The switchable...
3D EM simulations are nowadays widely used to design antenna systems, RF components and RF modules. The FDTD method shows significant advantages compared to frequency domain methods if the problems are getting complex and have to consider thousands of objects and complex multilayer circuits. This paper describes how the FDTD XPU technology (software accelerated computing on modern CPUs) can utilize...
In this study, numerical and experimental analysis of a dual band (Medical Implant Communications Service-MICS; 402–405 MHz, Industrial, Scientific and Medical-ISM; 2.4–2.48 GHz) implantable antenna design for biomedical applications are presented. The proposed antenna is in the type of stacked Planar Inverted-F Antenna (PIFA) covered with a superstrate. The antenna has a size of 2 cm × 1 cm × 3.81...
A multiband planar printed monopole antenna with Minkowski and Lollipop defected parasitic structure (DPS) for wireless communication system is proposed. The proposed antenna can create and work effectively to covers triband resonance frequencies at 2.4, 3.6 and 5.8 GHz within WLAN/WiMAX range in wireless communication system application. The Minkowski and Lollipop DPS has been place in front of and...
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