Timothy Pelham

University of Bristol | UB · Department of Electrical and Electronic Engineering

The design of conformal antenna arrays has historically been carried out by warping suitable planar antenna arrays to the desired radius of curvature. There has been little investigation into the effects of characteristic antenna performance on conformal array performance as the radii of curvature is varied. This paper presents a Variable Geometry...

In the pursuit of cost effective conformal antenna array design, an efficient and fast Finite-Difference Time Domain (FDTD) model is a highly desirable tool. This paper evaluates the performance of the University of Bristol Electrical Engineering Departments FDTD Model. The model is used to predict the antenna array patterns and inter element coupl...

Conformal Antenna Arrays offer many advantages for aerospace platforms, especially if selected early in the platform design cycle. To this end a Conformal antenna array directivity equation is presented, allowing the benefits of a conformal antenna array to be explored and design trade-offs considered at an early stage. The Conformal Directivity eq...

Conformal Antenna Arrays are becoming increasingly attractive for aerospace, medical imaging, and 5G communications. While developments in Electro-Magnetic solvers allows accurate conformal array analysis, this study presents a method for predicting the maximum gain pattern for conformal antenna arrays using Standard Triangular/Tessellation Languag...

Conformal antenna arrays have long represented an attractive solution to challenges imposed by an electromagnetic aperture on an aerospace platform. This allows designers to trade between array positioning and geometry, and avoids the significant aerodynamic drag of a planar array. This is hampered by the expense of the design and computational mod...

Gigascale antenna arrays (3 to 4 orders of magnitude more elements than the largest ever built) are a critical component of proposed space-based solar power (SBSP) systems. The transmitting antenna arrays in orbit are expected to be up to 3 km2, while the receiving arrays on Earth have been proposed at up to 77 km2. There are many challenges and ri...

The mechanical vibrations of a high-strain glass-fibre composite deployable X-band synthetic aperture radar (SAR) antenna structure are investigated using a finite element method. The antenna is approximately 2 m×0.3 m , and exhibits natural frequencies at 2.8 Hz and 7.6 Hz. The radiation patterns for a reflectarray formed from the structure are ca...

The design of antenna arrays to meet complex requirements in sensors and communications depends upon access to robust tools to access and prototype potential antenna arrays on their intended structures without the need for in depth antenna design. Together with the simulation of wider communications and imaging problems, there is a pressing need fo...

p>The development of the networked battlespace as a concept, and the wealth of wired and wireless communications to support it have opened the door to truly multidimensional radar systems. Whether as a static network of radars coordinating to provide national coverage, or a local network for UAV’s providing a swarm aperture for rapidly reconfigurab...

p>The development of the networked battlespace as a concept, and the wealth of wired and wireless communications to support it have opened the door to truly multidimensional radar systems. Whether as a static network of radars coordinating to provide national coverage, or a local network for UAV’s providing a swarm aperture for rapidly reconfigurab...

The increased use of radar systems in new form factors from automotive to small unmanned aerial vehicles requires the development of robust and accessible methods for virtual prototyping. Allowing a project team to evaluate the influence of platform structure, antenna or array geometry and beamforming architecture on overall system performance. Usi...

This paper evaluates the performance of three-dimensionally (3D) printed spiral phase plates (SPPs) for enabling an orbital angular momentum (OAM) multiplexed radio system. The design and realization of the SPPs by means of additive manufacturing exploiting a high-permittivity material is described. Modes 1 and 2 SPPs are then evaluated at 15 GHz i...

Sub 6GHz wireless User Equipment is carried out using cabled disconnecting the antenna. Additionally SISO and MIMO over the air (OTA) test methods have been developed to measure antenna efficiency and the impact of the channel spatial correlated of the data streams. The 5G standard will utilise the large available bandwidth at millimetre wave frequ...

Conformal Antenna Arrays, a broad description covering a distributed array across d different sections of a ships superstructure, or a tightly integrated concave hemisphere for microwave mammography. Whether military radar, modern wireless communications or medical imaging, conformal antenna arrays offer an attractive method of bridging the gap bet...

Low-energy resonances in 31P(p, α 28Si and 35Cl(p, α)32S were studied directly in order to gain a better understanding of reaction cycling in the Si-Ar region in novae. New resonance strengths at E c.m. = 600 and 622 keV in 31P(p, α)28Si were measured (ωγ p, α = (2.2#x00B1;0.7) × 10−2 eV and ωγ p, α = (0.99±0.08) eV, respectively) as well as the...

Reaction cycles in explosive hydrogen burning in novae and X-ray bursts influence both the energy generation and the processing of material to higher masses. The ^31P(p,α)^28Si and ^35Cl(p,α)^32S reactions are thought to lead to the formation of reaction cycles in the Si-Ar region, but the strength of these cycles depends on the (p,γ)/(p,α) reactio...

Neutron capture reactions on unstable nuclei are important for both basic and applied nuclear science. A program has been developed at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory to study single‐neutron transfer (d,p) reactions with rare isotope beams to provide information on neutron‐induced reactions on unstable n...

An ongoing study is presented into the resonant states of 6Be via simulation of d(7Be,t)6Be with Fresco to investigate the results of ``Searching for resonances in the unbound 6Be nucleus'' a paper by K.Y. Chae [1]. In this paper the d(7Be,t)6Be reaction was studied to search for resonances in the 6Be nucleus that may be used to increase our knowle...