# IET Microwaves, Antennas & Propagation

## Filter Results

Displaying Results 1 - 25 of 43
• ### 2.4 GHz Class-E power amplifier with transmission-line harmonic terminations

Publication Year: 2007, Page(s):267 - 272
Cited by:  Papers (7)  |  Patents (1)
| |PDF (730 KB)

The design procedure, fabrication and measurement of a Class-E power amplifier with excellent second- and third-harmonic suppression levels are presented. A simplified design technique offering compact physical layout is proposed. With a 1.2 mm gate-width GaAs MESFET as a switching device, the amplifier is capable of delivering 19.2 dBm output power at 2.41 GHz, achieves peak PAE of 60% and drain ... View full abstract»

• ### Application of dual-mode filter techniques to the broadband matching of microstrip patch antennas

Publication Year: 2007, Page(s):273 - 276
Cited by:  Papers (5)
| |PDF (266 KB)

Structures such as square or circular microstrip patch antennas may support two orthogonal resonant modes. The paper presents a new method of utilising the dual-mode property to increase the bandwidth of microstrip antennas. The input impedance of such a dual-mode antenna may be represented as a second-order ladder network of coupled resonators, where each resonator is coupled to a load resistor. ... View full abstract»

• ### Wideband microstrip patch antenna design for breast cancer tumour detection

Publication Year: 2007, Page(s):277 - 281
Cited by:  Papers (34)  |  Patents (1)
| |PDF (422 KB)

A patch antenna is presented which has been designed to radiate frequencies in the range 4-9.5 GHz into human breast tissue. The antenna is shown by means of previously unpublished simulation and practical measurements to possess a wide input bandwidth, radiation patterns that remain largely consistent over the band of interest and a good front-to-back ratio. Consideration is also given to the ant... View full abstract»

• ### Identification of melting snow using data from dual-frequency microwave links

Publication Year: 2007, Page(s):282 - 288
Cited by:  Papers (3)
| |PDF (263 KB)

Using data from a dual-frequency microwave link it is possible to identify periods of transmission affected by melting snow. This is because, in melting snow, the relation between attenuation and the amount of precipitation is nonlinear and depends on the frequency in a way that differs from the dependence in rain. This implies that the ratio of the single-frequency estimates of apparent rainfall ... View full abstract»

• ### 'Surrounded-element' approach for the simulation of reflectarray radiating cells

Publication Year: 2007, Page(s):289 - 293
Cited by:  Papers (16)
| |PDF (680 KB)

A new approach to analyse reflectarray cells is presented, which allows mutual coupling effects to be realistically accounted for by simulating each radiating cell with its actual neighbouring cells, either identical or not. The proposed approach is compared to more conventional approaches that consider either an infinite periodic environment or that neglect coupling effects. A comparison between ... View full abstract»

• ### Low profile wideband embedded dielectric resonator

Publication Year: 2007, Page(s):294 - 298
Cited by:  Papers (9)
| |PDF (466 KB)

A dielectric resonator antenna (DRA) made of high dielectric constant substrate is studied. Embedding a higher dielectric disk inside the substrate disk enhances the bandwidth. A narrow slot excites the DRA. Embedded DRAs of different shapes are considered for wideband applications. An eye-shaped DRA made with a circular dielectric resonator disk embedded in an elliptical-shaped host' DRA is foun... View full abstract»

• ### Wideband stair-shaped dielectric resonator antennas

Publication Year: 2007, Page(s):299 - 305
Cited by:  Papers (30)
| |PDF (528 KB)

Wideband stair-shaped dielectric resonator antenna (DRAs) are designed. Wide bandwidths are achieved with one-step or two-steps stair geometries. Cricular and square cross-sections are discussed with two different excitation methods: coaxial feed and aperture coupled. The DRAs are designed in the X-band. An impedance bandwidth (S11<-10 dB) of 54.3% is obtained with the two-steps stai... View full abstract»

• ### On the two dimension applications of high-order vector finite elements to the study of electromagnetic resonance

Publication Year: 2007, Page(s):306 - 313
Cited by:  Papers (5)
| |PDF (763 KB)

A set of hybrid vector-scalar finite elements for curved-triangle meshes is developed. These elements are applied to the study of electromagnetic resonance problems in which the variation in the field components along one coordinate is known in advance. The field component along this coordinate is modelled with polynomials of degree q. The other two field components are modelled with two dimension... View full abstract»

• ### Frequency-selective surfaces for GPS and DCS1800 mobile communication. 1. Quad-layer and single-layer FSS design

Publication Year: 2007, Page(s):314 - 321
Cited by:  Papers (3)
| |PDF (893 KB)

In the paper, frequency selective surfaces (FSS) composed of quad-layer FSS with staggered tuning are designed, to allow signals to pass through at the frequency range of the global positioning system (GPS) cum DCS1800 mobile communications operation, while rejecting signals at the higher frequencies. The FSS is analysed by visualising the transformation of the admittance locus on the Smith chart,... View full abstract»

• ### Frequency-selective surfaces for GPS and DCS1800 mobile communication. 2. Integration with antenna for scattering reduction

Publication Year: 2007, Page(s):322 - 327
Cited by:  Papers (1)
| |PDF (618 KB)

The paper describes a novel attempt to integrate a quad-layer frequency selective surface (FSS) with a circularly polarised Maltese-cross antenna for the global positioning system and DCS 1800 mobile communications. The effect of integrating the FSS with the antenna is presented for both in-band (1.5-1.9 GHz) and out-of-band (8.5-9.7 GHz) operation. For out-of-band operation, a reduction of antenn... View full abstract»

• ### Accurate and efficient method for analysis of scattering from dielectric shell of rotation by least-squares algorithm

Publication Year: 2007, Page(s):328 - 334
Cited by:  Papers (1)
| |PDF (304 KB)

A novel and robust method for analysis of scattering from dielectric shells of rotation is presented. The calculation was done by using an E-fieldH-field integral equation plus the method of least-squares rather than using the combined field integral equation. The use of the E-fieldH-field integral equation defined just inside or outside the surfaces makes the source points and the field points sl... View full abstract»

• ### Spectral domain analysis of frequency-selective surfaces on biaxially anisotropic substrate

Publication Year: 2007, Page(s):335 - 340
Cited by:  Papers (3)
| |PDF (339 KB)

A full-wave analysis is presented of frequency-selective surfaces (FSSs) on a biaxially anisotropic substrate. The integral equations are first transformed into the spectral domain ones through the use of the Floquet theorem and then solved by the method of moments. Since the wave immittance of the biaxially anisotropic substrate is derived in a closed form, the resulting impedance matrix can be o... View full abstract»

• ### Half width leaky wave antennas

Publication Year: 2007, Page(s):341 - 348
Cited by:  Papers (78)
| |PDF (523 KB)

First Page of the Article
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• ### Nonreciprocal left-handed transmission characteristics of microstriplines on ferrite substrate

Publication Year: 2007, Page(s):349 - 354
Cited by:  Papers (14)
| |PDF (187 KB)

In this paper, a nonreciprocal left-handed transmission line has been investigated. It is composed of a normally magnetised ferrite microstripline periodically loaded with lumped capacitances and inductive stubs. Based on the simple equivalent circuit model for a predominant edge guided mode, the dispersion relation of the ferrite left-handed transmission line has been estimated, providing the bac... View full abstract»

• ### Statistical modelling of building transmission in a cellular urban environment

Publication Year: 2007, Page(s):355 - 362
| |PDF (417 KB)

Channel sounding measurements have been reported which show that transmission through buildings can be important for microcellular coverage planning. A theoretical-statistical model for propagation through a building, or row of buildings, is proposed in the paper. Expressions for the mean and covariance of the channel transfer function are obtained and compared with measurements. The model exhibit... View full abstract»

• ### Direct conversion receivers using multiport structures for software-defined radio systems

Publication Year: 2007, Page(s):363 - 372
Cited by:  Papers (7)
| |PDF (770 KB)

An analytical assessment for multiport structures as direct conversion receivers is presented. A new direct-conversion receiver based on a novel five-port structure suitable for software-defined radio applications is proposed. The five-port architecture provides some advantages compared with previous architectures. Numerical and microwave simulations have been conducted to show its capabilities as... View full abstract»

• ### Specific attenuation and depolarisation in rain from 2-dimensional video disdrometer data

Publication Year: 2007, Page(s):373 - 380
Cited by:  Papers (5)
| |PDF (482 KB)

Data from 2-dimensional video disdrometers (2DVD) taken in different locations are used to derive the specific attenuation for horizontal and vertical polarisations at 20 GHz. The data include both drop-size distribution and their axis ratio distributions. T-matrix calculations using data over 1 min integration time show a power-law dependence on rain rate. The best-fit coefficients are compared w... View full abstract»

• ### Treatment of arbitrarily-orientated multiwire bundles and terminated multiwire transmission lines in FDTD method

Publication Year: 2007, Page(s):381 - 387
Cited by:  Papers (7)
| |PDF (764 KB)

The finite-difference time-domain (FDTD) method is extremely versatile and widely used but there still remain structures in which the method encounters serious difficulties. One such situation is the analysis of bundles of closely spaced wires which are not parallel to the FDTD mesh. Similar problems are encountered in the analysis of multiconductor transmission lines such as PCB tracks. Recent re... View full abstract»

• ### A millimetre-wave bandpass filter-lens array

Publication Year: 2007, Page(s):388 - 395
Cited by:  Papers (29)
| |PDF (663 KB)

A filter-lens array (FLA) is a planar array of bandpass integrated antenna-filter-antenna (AFA) elements which are stagger-tuned in the vicinity of a centre frequency, so as to provide the phase shift required for transforming spherical and planar wavefronts. Due to the filtering response of the AFA elements, FLA presents a bandpass gain and can act as a combination of a conventional lensarray and... View full abstract»

• ### Broadband low-profile antennas for wireless applications

Publication Year: 2007, Page(s):396 - 400
Cited by:  Papers (2)
| |PDF (378 KB)

Two novel broadband low-profile antennas are developed for the mobile terminals of wireless applications. The first one is a quasiplanar antenna which has a height of 0.06lambda0, where lambda0 is the free-space wavelength at the centre frequency. The second one is a planar antenna which has a height of 0.056lambda0. It is demonstrated that the quasiplanar antenna ... View full abstract»

• ### Printed antennas with variable conductive ink layer thickness

Publication Year: 2007, Page(s):401 - 407
Cited by:  Papers (20)
| |PDF (462 KB)

One of the complex tasks in mass production of RF electronics is printing the communication antenna using electrically conductive ink. For example, this is very common for radio- frequency identification (RFID) tags. Electrical properties of the ink are mostly determined by conductive (e.g. silver) particles mixed into the ink solution and the way they connect' in the cured ink. It is also desira... View full abstract»

• ### Dualband frequency-selective surfaces using substrate-integrated waveguide technology

Publication Year: 2007, Page(s):408 - 413
Cited by:  Papers (10)
| |PDF (363 KB)

This paper proposes a dualband frequency-selective surface (FSS) based on substrate-integrated waveguide (SIW) technology. This novel dualband FSS is constructed using double square loop slots (DSLSs) and an SIW cavity. Its frequency performance is investigated by numerical simulation using the finite difference frequency domain (FDFD) method. Another dualband FSS, constructed using convoluted dou... View full abstract»

• ### Reconfigurable patch-antenna design for wideband wireless communication systems

Publication Year: 2007, Page(s):414 - 419
Cited by:  Papers (18)
| |PDF (463 KB)

An effective design of a reconfigurable patch antenna, with a wide operational bandwidth for wireless communication and radar systems, is presented in this paper. The reconfigurable patch possesses an E-shaped structure and its operation frequency can be changed by integrated switches. The operational frequency of the antenna can cover an octave frequency range by utilising only two switch states.... View full abstract»

• ### Broadband-configurable bandstop-filter design employing a composite tuning mechanism

Publication Year: 2007, Page(s):420 - 426
Cited by:  Papers (13)
| |PDF (355 KB)

A microwave bandstop-filter design is reported, which combines both continuous and discrete tuning using varactor and PIN diodes to achieve a two-octave tuning range. The useable passband for any given tuning point is limited, however, the composite tuning mechanism in the topology facilitates the separate tuning of the centre frequency and stopband to minimum-loss passband separation. A suitable ... View full abstract»

• ### Improvement of performance of optically controlled microstrip phase shifters

Publication Year: 2007, Page(s):427 - 432
Cited by:  Papers (1)
| |PDF (495 KB)

Two optically controlled phase shifters are proposed. The first structure is based on the microstrip ring resonator inserted between two gaps. Phase-shifting is performed by optically controlling the gaps capacitance. The structure has shown excellent characteristics, however the rejection rate is high. To minimise the reflected power, the second phase shifter, which is based on the rat race coupl... View full abstract»

## Aims & Scope

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

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