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The performance of a novel taper slot antenna (TSA) with a tapered profile that conforms to a fourth order polynomial function is reported. This polynomial tapered profile has a larger opening rate at higher frequency than the conventional Vivaldi flare. A short 0.5lambda long polynomial flared TSA was modelled and its computed properties compared with those of a Vivaldi of similar length. The polynomial...
Millimetric systems offer the dual advantages of small size and increased bandwidth but have limitations on paper-handling capabilities. Minimisation of loss in the system is therefore of critical importance. A low-loss air-spaced method developed at the University of Birmingham is investigated in this paper in two ways. A single-frequency millimetric prototype was designed to investigate the use...
This paper describes the multiband antenna which has been designed for the ESPACENET satellite sensor node based on the CubeSat framework. The work investigates the primary applications the satellite will perform and then lists the key frequencies for each of these applications. The antenna is designed using standard micro machining techniques, to create a micro antenna which can be easily fabricated...
Bandwidth is the limiting factor in using electromagnetic band gap materials (EBGs). Many studies have been carried out on optimizing EBG geometries to increase bandwidths with limited success. This paper will present an antenna integrated with a high impedance electromagnetic bandgap surface (HIS) that can be independently tuned over two separate frequency bands. The HIS consists of a dual layer...
In this paper we propose a novel combination of orthogonal frequency division multiplexing (OFDM) and the orbital angular momentum (OAM) of the electromagnetic field to produce a novel orthogonal momentum division multiplexing (OMDM) technique. This OMDM technique is applied to a satellite diversity system employing three satellites. Simulation results show that the proposed OMDM-satellite diversity...
Several examples of wide bandwidth Vivaldi antenna are presented to illustrate bandwidths up to 10:1. Modern computational methods can be used by experienced designers to achieve this performance. Traditional Vivaldi antenna arrays cannot be easily fabricated as modular structures because they require electrical contact between adjacent elements. The Balanced Antipodal Vivaldi Antenna is modular,...
There is currently an interest in military and civil domains for the development of antennas which can be worn on the body. For safe and comfortable operation of the antennas they must be designed to be unobtrusive. In the application considered in this work, the antennas are also required to cover a wide bandwidth, both in terms of input performance and stable radiation patterns. Satisfying all these...
A parametric study on the physical attributes of a planar inverted F antenna is to be presented. The PIFA under investigation does not have a shorting via to the ground in contrast to most other designs. The antenna is printed on a high frequency laminate, thus maintaining low profile, ease of fabrication and good fabrication tolerances. Varied antenna parameters include length of the upper and lower...
Array based radar sensing systems are set to become the norm in future systems. Current array based systems tend to operate at the sub-array level often condensing the received echo information into one or two channels only. Processing of the received data is often relatively simple with a few fixed modes of operation. Future trends are largely two-fold. Firstly there is a move from a small number...
A log periodic dipole array with switching to select sub-bands is presented. Recently we have proposed a 3 to 1 bandwidth reconfigurable printed dipole antenna with harmonic trap. One of the frequency bands can be selected by changing the length of the dipole. In this paper a reconfigurable log periodic printed dipole array (LPDA) is proposed. The frequency bands can be selected by switching the printed...
UWB receivers require highly pure signals to facilitate detection and reduce bit error rate. A linear array radiating Gaussian monocycle is analyzed in the time domain. It is shown that the signal radiated in the direction of maximum gain suffers no distortion. But in all other directions the radiated signal is highly distorted. Analysis of the array in the frequency domain provides significant insight...
A novel wideband microstrip fed printed quasi-Yagi antenna is investigated for potential use in phased array applications. The antenna consists of two parallel wideband dipole radiators of different and overlapping resonant lengths. The elements are fed via a microstrip to stripline transmission line network. The use of two dipole elements maintains radiation pattern shape and gain over a wide operating...
This paper presents a 2.45 GHz patch antenna over an EBG substrate with the objective of higher radiation efficiency and compact operation in close proximity to a lossy medium, both of which are critical for body worn antennas. To achieve compact size, several sizes of EBG are included and the individual antenna efficiency and radiation pattern are studied. From these results, the EBG substrate demonstrates...
An investigation into the effects on the axial ratio of a circularly polarised patch antenna placed on a Sievenpiper type high impedance surface (HIS) is presented. This paper highlights a phenomenon observed in the axial ratio and gain of a circularly polarised antenna when its ground plane is a high impedance surface; the angular position of the antenna on the high impedance surface is critical...
The initial applications of active electronically scanned array antennas (AESA) in radar (and other) applications have been in areas where a narrow operating bandwidth (<10%) has been acceptable. However, although the cost of an AESA has reduced in recent years it is still a relatively expensive asset. Also, space on a military platform such as a fighter aircraft is at a premium. There is therefore...
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