IET Microwaves, Antennas & Propagation

Filter Results

Displaying Results 1 - 17 of 17
• Study of broadband near-field antenna for ultra-highfrequency radio frequency identification applications

Publication Year: 2011, Page(s):1661 - 1669
Cited by:  Papers (2)
| | PDF (835 KB)

A novel antenna for applications in an ultra-high-frequency (UHF) radio frequency identification (RFID) reader system is proposed and investigated. The antenna achieves a gain of lower than -10-dBi in all directions with strong magnetic field distribution over the entire UHF RFID band of 830-950-MHz as well as good performance in detecting tags when applied in UHF RFID systems. The antenna configu... View full abstract»

• Design and optimisation of a novel dual-band circularly polarised microstrip antenna

Publication Year: 2011, Page(s):1670 - 1674
Cited by:  Papers (1)
| | PDF (400 KB)

A novel dual-band circularly polarised patch feed antenna is presented. It is theoretically analysed and simulated. It is optimised with a genetic algorithm (GA) which is capable of producing an antenna design that has a low voltage standing wave ratio (VSWR), low cross-polarisation and large bandwidths but small dimensions. A hybrid finite-element method/method of moment model was used to simulat... View full abstract»

• Reconfigurable tri-band H-shaped antenna with frequency selectivity feature for compact wireless communication systems

Publication Year: 2011, Page(s):1675 - 1682
Cited by:  Papers (10)
| | PDF (994 KB)

This study presents an H-shaped reconfigurable antenna for wireless applications. The antenna consists of an H-shape radiator and a CPW printed on a circuit board and a varactor diode connecting the upper and lower arms of the H-shape radiator for reconfigurability. The uniqueness of the antenna lies on the ability to select the operating mode and frequencies electronically using a varactor diode.... View full abstract»

• Miniature microstrip-fed ultra-wideband printed monopole antenna with a partial ground plane structure

Publication Year: 2011, Page(s):1683 - 1689
Cited by:  Papers (12)
| | PDF (662 KB)

A new microstrip-fed planar monopole antenna is presented for ultra-wideband (UWB) communication systems. The antenna structure consists of a dome-topped, bowl-shaped patch with a truncated ground plane structure. The ground plane is predominately tapered and includes a notch below the feed-line in the vicinity of the patch. The effects of dimensional parameters on the performance of the antenna h... View full abstract»

• Fast integral equation-fourier transformation algorithm with grid-robust higher-order vector basis

Publication Year: 2011, Page(s):1690 - 1696
Cited by:  Papers (2)
| | PDF (506 KB)

An integral equation-fast Fourier transformation (IE-FFT) with grid-robust higher order vector basis functions (BFs) are presented. A conformal mesh is required for traditional BFs based on common edges between adjacent elements. This is a very rigorous requirement for large and complicated electrical geometries. Instead of a conformal mesh, grid-robust higher-order vector BFs are used here. It ma... View full abstract»

• Reduced log-periodic dipole antenna using a cylindrical-hat cover

Publication Year: 2011, Page(s):1697 - 1702
Cited by:  Papers (7)
| | PDF (710 KB)

A technique to decrease the size of log-periodic dipole array (LPDA) antennas employing inductive loads on its elements is introduced. This technique consists of adding a short-circuited cylindrical hat cover at the end of each arm of the antenna. Simulation and measurement results show that the total area, if considered as a trapezoid, of a fabricated LPDA antenna, based on the proposed technique... View full abstract»

• Computation of the scattered fields from a dielectric object buried in a medium with a periodic surface by a decomposition method

Publication Year: 2011, Page(s):1703 - 1709
Cited by:  Papers (3)
| | PDF (534 KB)

The electromagnetic scattering from a cylindrical dielectric object of arbitrary cross-section buried in a lossy dielectric half-space having a periodic surface is investigated using a new numerical method. The method is outlined for TMz (horizontally) polarised incident wave. The surface equivalence principle and a decomposition method are employed to form a set of electric field integ... View full abstract»

• Trends in the incidence of rain height and the effects on global satellite telecommunications

Publication Year: 2011, Page(s):1710 - 1713
| | PDF (484 KB)

Satellite communications using millimetre waves, in Ka band and above, experience significant fading by rain. Strong attenuation is experienced between the ground station and a level known as the rain height, in ITU-R recommendations assumed to be 360 m above the zero-degree isotherm (ZDI). This study examines National Oceanic and Atmospheric Administration National Centres for Environmental Predi... View full abstract»

• Multi-layer quadrature hybrid coupler design composed of multiple circular sectors

Publication Year: 2011, Page(s):1714 - 1719
| | PDF (483 KB)

A hybrid coupler design composed of multiple circular sectors is presented. It is designed to cover wireless local-area network bands at 2.4, 5.25 and 5.8 GHz, ultra-wideband at 3.1 4.8 GHz, digital multimedia broadcasting at 2.6 GHz and WiMax at 3.5 GHz. The coupler achieves an amplitude imbalance of 1 dB and a phase error of 5 at the outputs within the design frequency range. The developed coupl... View full abstract»

• Dual-band matching technique based on dual-characteristic impedance transformers for dual-band power amplifiers design

Publication Year: 2011, Page(s):1720 - 1729
Cited by:  Papers (19)
| | PDF (701 KB)

This study demonstrates a novel matching network synthesis technique that matches any arbitrary reflection coefficient seen by the active device at two uncorrelated frequencies to the standard 50 load. The proposed matching network is fully transmission line based and, hence, can be used in high-power applications at higher frequencies. Unlike previously reported dual-band matching techniques, thi... View full abstract»

• Reconfigurable cascaded coupled line filter with four distinct bandwidth states

Publication Year: 2011, Page(s):1730 - 1737
Cited by:  Papers (4)
| | PDF (751 KB)

This study presents a cascaded coupled line filtering structure for the development of high-order reconfigurable microwave filters. A reconfigurable bandpass filter of this type that is capable of switching between four distinct bandwidth states ranging from around 20 to 50% 3%dB fractional bandwidth centred at 2%GHz, is described. The filter exhibits insertion losses ranging from 0.47 to 5.5%dB. ... View full abstract»

• Received signal strength in large-scale wireless relay sensor network: A stochastic ray approach

Publication Year: 2011, Page(s):1738 - 1743
Cited by:  Papers (3)
| | PDF (299 KB)

The authors consider a point percolation lattice representation of a large-scale wireless relay sensor network (WRSN) deployed in a cluttered environment. Each relay sensor corresponds to a grid point in the random lattice and the signal sent by the source is modelled as an ensemble of photons that spread in the space, which may hit other sensors and are scattered around. At each hit, the rela... View full abstract»

Publication Year: 2011, Page(s):1744 - 1749
Cited by:  Papers (2)
| | PDF (724 KB)

Tapered impedance loading is studied to suppress edge scattering from a rectangular metallic plate. Associated with the pattern multiplication theorem, a simple approach to this scattering problem is proposed assuming the current distribution of the target is broken into an array of overlapping triangles. This tapered impedance is realised by geometric variations based on frequency-selective surfa... View full abstract»

• Enhanced performance of a patch antenna using spiral-shaped electromagnetic bandgap structures for high-speed wireless networks

Publication Year: 2011, Page(s):1750 - 1755
Cited by:  Papers (3)
| | PDF (462 KB)

This study describes the improvement of gain and bandwidth of a microstrip patch antenna achieved using a spiral-like electromagnetic bandgap (EBG) structure for high-speed wireless local area networks. The size of the antenna is only 45 × 45 × 2.47 mm and resonates at a frequency of 2.4 GHz. The gain and bandwidth of this antenna is 3 dBi and 67.4% greater than a conventional patch ... View full abstract»

• Radiation field computation of leaky coaxial cables by finite-difference time domain in cylindrical coordinates and equivalent source integration

Publication Year: 2011, Page(s):1756 - 1762
Cited by:  Papers (1)
| | PDF (834 KB)

A combined scheme involving a conventional perfectly matched layer and lossy material is proposed for absorbing both the radiating and evanescent waves of leaky coaxial cables (LCX) efficiently. After parameter optimisation and correctness verification, the combined absorbing boundary is used to calculate the near field of LCX with horizontal triangle slots. The radiation field is then obtained by... View full abstract»

• Integrated closed-form model and circuit model of lossy slot line

Publication Year: 2011, Page(s):1763 - 1772
Cited by:  Papers (1)
| | PDF (585 KB)

An integrated closed-form model and circuit model are used to compute the conductor thickness-dependent effective relative permittivity εeff(f, t), characteristic impedance Z0(f, t), dielectric loss αd(f, t) and conductor loss αc(f, t) of a slot line. The circuit model de... View full abstract»

• Wideband antenna using a multiple-mode slotline radiator: Proposal and implementation

Publication Year: 2011, Page(s):1773 - 1778
| | PDF (1007 KB)

A novel wideband antenna with a multiple-mode radiator on slotline is proposed. This slotline resonator is asymmetrically fed at a right angle by a short-ended microstrip line on the opposite side of the substrate. First, parametric studies are executed on frequency-dependent input impedance with respect to feeding positions and slot/strip widths, aiming at simultaneously exciting its first and se... View full abstract»

Aims & Scope

IET Microwaves, Antennas & Propagation covers all aspects of microwave and antenna engineering and propagation.

Full Aims & Scope

Meet Our Editors

IET Research Journals
iet_map@theiet.org