# IET Microwaves, Antennas & Propagation

## Filter Results

Displaying Results 1 - 12 of 12
• ### Tri-band bandpass filters using modified tri-section stepped impedance resonator with improved selectivity and wide upper stopband

Publication Year: 2013, Page(s):1187 - 1193
Cited by:  Papers (1)
| | PDF (741 KB)

This study presents tri-band bandpass filters using two variant designs based on tri-section stepped impedance resonators (SIR) to achieve passband selectivity. The passbands are centred about 2.4, 3.5 and 5.5 GHz, respectively. The first design pertains to an asymmetric stepped impedance stub-loaded tri-section SIR and the second one consists of embedded SIR. Both the techniques contribute in imp... View full abstract»

• ### Rapid optimisation of omnidirectional antennas using adaptively adjusted design specifications and kriging surrogates

Publication Year: 2013, Page(s):1194 - 1200
Cited by:  Papers (7)
| | PDF (329 KB)

A methodology for rapid design optimisation of omnidirectional antennas is presented. In order to reduce the computational cost of the geometry parameter adjustment process the authors exploit coarse discretisation electromagnetic (EM) simulations of the antenna structure under consideration as its low-fidelity model. A fast response surface approximation (RSA) model of the sampled EM data is crea... View full abstract»

• ### Directional modulation transmitter radiation pattern considerations

Publication Year: 2013, Page(s):1201 - 1206
Cited by:  Papers (12)
| | PDF (721 KB)

A pattern synthesis approach is applied to a directional modulation (DM) system. A systematic synthesis procedure is suggested which ensures optimal constellation patterns production along pre-specified communication directions, whereas simultaneously conserving energy dispersal in other directions. In this study, the properties of DM systems synthesised from Gaussian magnitude far-field radiation... View full abstract»

• ### Power recycling concept applied to distributed amplification

Publication Year: 2013, Page(s):1207 - 1214
| | PDF (711 KB)

A novel distributed amplifier structure based on a power recycling scheme is proposed. It allows the amplifier gain to be enhanced while providing optimum output power and a perfect input match within a moderate bandwidth. The ideal performance of this novel distributed amplifier, called the power recycling distributed amplifier, is analysed. Limitations introduced by mismatch and losses in the ga... View full abstract»

• ### Inductor-less envelope modulated radio frequency power amplifier using stacked amplifiers and envelope shaping

Publication Year: 2013, Page(s):1215 - 1220
Cited by:  Papers (1)
| | PDF (553 KB)

An envelope modulated radio frequency (RF) power amplifier (PA) is presented using a stacked amplifiers' modulator. The modulator combines the efficiency of class G with the convenience of a charge pump. Since it is a single band modulator, no large inductors or transformers are required. A two level prototype has been developed and tested with a 7.5 dB peak-to-average power ratio 1.4 MHz bandwid... View full abstract»

• ### Resemblance between gap waveguides and hollow waveguides

Publication Year: 2013, Page(s):1221 - 1227
Cited by:  Papers (12)  |  Patents (1)
| | PDF (1113 KB)

There is a lack of suitable numerical ports for the gap waveguides. This study studies the resemblance between the ridge/groove gap waveguide and the conventional hollow ridge/rectangular waveguide, respectively, by using numerical analysis. The dispersion diagrams and characteristic impedances are compared and found to be similar within the stopband of the parallel-plate modes. Therefore conventi... View full abstract»

• ### Optimal polarised pattern synthesis of wideband arrays via convex optimisation

Publication Year: 2013, Page(s):1228 - 1237
Cited by:  Papers (5)
| | PDF (1093 KB)

The digital wideband arrays with data converters and digital signal processing capability permit greater flexibility in the pattern synthesis than conventional time-delay steered wideband arrays, which provides an opportunity to solve the polarised pattern synthesis of wideband arrays by using numerical optimisation algorithms. A finite-impulse response (FIR) filter is placed at each element to di... View full abstract»

• ### Antenna miniaturisation and broadband design via a decomposition of structure into conjugated elemental antennas for natural impedance matching

Publication Year: 2013, Page(s):1238 - 1246
Cited by:  Papers (1)
| | PDF (1168 KB)

This study introduces a useful technique for an effective antenna design to achieve size miniaturisation or broadband operation. The key idea is the decomposition of the antenna structure into several elemental parts having naturally conjugate input reactance values. Each of the decomposed elemental parts serves as both the matching element and radiator simultaneously, instead of simply being lump... View full abstract»

• ### Accurate method for synthesis of shaped-beam non-uniform reflectarray antenna

Publication Year: 2013, Page(s):1247 - 1253
Cited by:  Papers (1)
| | PDF (550 KB)

This study presents an accurate method to synthesise a shaped-beam flat reflectarray (RA) antenna based on the phase synthesis of its equivalent aperture. For this purpose particle swarm optimisation is used to determine the optimal phase distribution on the reflective surface of the antenna. Furthermore, by dividing the equivalent aperture of the antenna into small parts and by appropriate approx... View full abstract»

• ### Genetic-based design of a tetra-band high-efficiency radio-frequency energy harvesting system

Publication Year: 2013, Page(s):1254 - 1263
Cited by:  Papers (28)
| | PDF (1080 KB)

In this study, we exploit genetic algorithms to design a rectenna required to harvest ambient radio-frequency (RF) energy from four different RF bands in critical (ultra-low power) conditions. For this purpose a set of multi-resonant annular-ring patch antennas are pixel-wise described inside an electromagnetic simulator to provide the population' of individuals among which the genetic tool is ab... View full abstract»

• ### Errata

Publication Year: 2013, Page(s): 1264
| PDF (27 KB)
• ### Errata

Publication Year: 2013, Page(s): 1265
| PDF (30 KB)

## Aims & Scope

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

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