Print ISSN 1751-8725
This journal was previously known as IEE Proceedings - Microwaves, Antennas and Propagation 1994-2006. ISSN 1350-2417. more..
Latest content
-
Electromagnetic scattering of H‐polarised cylindrical wave by a double‐sided impedance circular strip
- Author(s): Vasil Tabatadze ; Ömer Faruk Alperen ; Kamil Karaçuha
- + Show details - Hide details
-
p.
1093
–1105
(13)
AbstractThe authors investigate electromagnetic scattering by a circular strip with impedance boundary conditions in detail. The excitation is obtained by the H‐polarised line source and the impedance boundary condition with different impedance values on each surface of the circular strip is imposed. Electromagnetic scattering from circular strips is formulated employing an integral equation approach including the orthogonal polynomials while expressing the current densities on inner and outer surfaces. To consider the edge condition, the current density on the scatterer is expressed in terms of Gegenbauer polynomials with the weighting function. Unlike the previous studies, the authors investigate the behaviour of the EM field regarding the location of the cylinder source, the size of the aperture and the different impedance values. The convergence of the proposed approach, which is one of the analytical–numerical methods, is investigated for different impedance values; considering the results, resonators with impedance surfaces of certain complex values and certain locations of the cylinder source perform better than the known PEC and PMC resonators for some specific resonance cases. An effective analytical–numerical approach is proposed for such geometry with the impedance boundary condition. An extensive analysis and comparison with other methods are provided. The limit cases of the impedance boundary condition (Dirichlet and Neumann boundary conditions) are validated.
The authors investigate the line source diffraction by a circular strip with different impedance value on inner and outer surfaces. As it is noticed, the resonance value becomes higher for the boundary condition corresponding to material in between PEC and PMC.image
-
Synthesis of flat‐top beampatterns based on simple polynomial transforms of Gaussian excitations
- Author(s): Goran Molnar ; Dorian Ljubenko ; Mile Šakić
- + Show details - Hide details
-
p.
1106
–1115
(10)
AbstractIn the design of antenna arrays which require fast and robust flat‐top beam synthesis, computationally efficient methods are preferred. This feature is usually met by analytical techniques or simple optimisation procedures. On the other hand, in the flat‐top beam synthesis, a common requirement is the ability to control beamwidth or sidelobe level. However, this can result in a high dynamic range ratio (DRR) of array's excitation coefficients. In this paper, a straightforward method for the design of symmetrical flat‐top arrays with controllable sidelobe level or DRR is proposed. The method is based on quadratic and cubic transforms of Gaussian excitations. In addition, the method utilises zero coefficients whose positions are used to control the DRR, including the ability to achieve its minimum. Compared to other flat‐top arrays with analytically shaped beams, the proposed arrays have lower DRRs for the same sidelobe level.
The design of antenna arrays forming flat‐top beams prefers robust and computationally efficient methods. These features are usually met by analytical techniques or simple optimisation procedures. A straightforward method is proposed for the design of quadratic‐ and cubic‐transformed Gaussian arrays forming flat‐top beams with controllable sidelobe level or dynamic range ratio of excitation coefficients.image
-
Method of phase compensation and pattern transformation for array antennas with arbitrarily oriented circularly polarised elements
- Author(s): Zhongtian Jing and Yubing Han
- + Show details - Hide details
-
p.
1116
–1129
(14)
AbstractThe inconsistent polarised directions and the radiation pattern transformation of the elements need to be considered in the analysis and simulation of large circularly polarised conformal arrays. Without relying on full‐wave simulations of the full array, a polarisation phase compensation and a pattern transformation method are proposed to solve these problems. When the position and orientation of the conformal array elements are known, the polarisation phase compensation method can provide a solution to keep the initial phase direction of each circularly polarised antenna element consistent in the global coordinate system. Then, a pattern transformation method is proposed to obtain the radiation pattern of each antenna in the global coordinate system. In this method, the local antenna polarised radiation patterns with amplitude and phase information are expressed in the global coordinate system through the mutual conversion relationship between the local and global coordinate systems. These methods can provide a guidance for array design and performance simulation, especially theoretically applicable to the arbitrary conformal arrays.
In this study, polarisation phase compensation and pattern transform methods are proposed. The polarisation phase compensation method can solve the problem of inconsistent polarised directions of elements in the conformal array with conventional excitation. The pattern transform method can obtain the radiation patterns of antennas in the conformal array without full‐wave simulation for the full array, which can greatly reduce the array design and analysis time.image
-
A 0.45‐V low‐power low‐noise amplifier using a wideband image‐rejection technology
- Author(s): Jian‐Yu Hsieh and Wei‐Ting Chen
- + Show details - Hide details
-
p.
1130
–1138
(9)
AbstractA 0.45‐V low‐power wideband image‐rejection low‐noise amplifier (LNA) using Taiwan Semiconductor Manufacturing Company (TSMC) 0.18‐μm CMOS process has been proposed. The supply voltage, power consumption and chip area of the proposed LNA can be reduced using forward body biasing, folded cascode topology and a feedback capacitor. Moreover, a wideband gain‐enhancement‐and‐image‐rejection (WGEIR) circuit including a variable resonant LC tank and a common‐gate amplifier has been developed. The inductance of the variable resonant LC tank can enlarge the gain of the proposed LNA. The capacitance of the variable resonant LC tank can achieve the image rejection. Using the WGEIR circuit, gain enhancement and wideband image rejection can be achieved simultaneously. The variable inductors and capacitors are developed for suppressing wideband image signals and good image rejection ratio (IRR). The combination of the variable inductors and capacitors can achieve eight image‐reject frequencies under three control voltages. The proposed LNA shows the measured results including a 10‐dB power gain, a 3‐dB noise figure (NF) and a −11‐dBm input third‐order intercept point (IIP 3) at 2.4 GHz, respectively. The measured IRR ranges from 18 to 23 dBc around 3.6–4.5 GHz, which is 900‐MHz image‐reject bandwidth. The measured proposed LNA using the mentioned techniques consumes 0.8‐mW power.
A 0.45‐V low‐power wideband image‐rejection low‐noise amplifier using Taiwan Semiconductor Manufacturing Company 0.18‐μm CMOS process has been proposed. Moreover, a wideband gain‐enhancement‐and‐image‐rejection circuit including a variable resonant LC tank and a common‐gate amplifier has been developed. The variable inductors and capacitors are developed for suppressing wideband image signals under low power consumption.image
-
Wideband single‐fed circularly polarised patch antenna
- Author(s): Liang Zhang ; Jia Chen ; Wenning Wang ; Zihang Qi ; Tongyu Ding
- + Show details - Hide details
-
p.
1139
–1144
(6)
AbstractA two‐layered wideband single‐fed circularly polarised (CP) antenna is presented by the authors. A single‐fed corner‐truncated square patch with four identical rectangular matching branches acts as a bottom‐driven patch to generate CP radiation. To broaden the 3‐dB axial ratio (AR) bandwidth, a similar patch with a larger size is loaded atop the driven patch as a parasitic patch. The measured results show that the proposed CP antenna has a 17.9% impedance bandwidth from 2.13 to 2.55 GHz and an 11% 3‐dB AR bandwidth from 2.15 to 2.4 GHz, respectively. The measured total gain is 7.1 dBic. The results indicate that the proposed antenna is a good candidate for Wireless Local Area Network band applications.
This paper proposed a two‐layered wideband single‐fed circularly polarised (CP) antenna. It realised a 17.9% impedance bandwidth from 2.13 to 2.55 GHz and a 13.1% 3‐dB AR bandwidth from 2.15 to 2.45 GHz, validating its applicability for Wireless Local Area Network use.image
Most downloaded
Most cited
-
Design, characterisation and fabrication of a broadband polarisation-insensitive multi-layer circuit analogue absorber
- Author(s): Saptarshi Ghosh ; Somak Bhattacharyya ; Kumar Vaibhav Srivastava
-
Design of frequency reconfigurable multiband compact antenna using two PIN diodes for WLAN/WiMAX applications
- Author(s): Yasir I. Abdulraheem ; George A. Oguntala ; Abdulkareem S. Abdullah ; Husham J. Mohammed ; Ramzy A. Ali ; Raed A. Abd-Alhameed ; James M. Noras
-
Eight-port orthogonally dual-polarised MIMO antennas using loop structures for 5G smartphone
- Author(s): Ming-Yang Li ; Zi-Qiang Xu ; Yong-Ling Ban ; Chow-Yen-Desmond Sim ; Zhe-Feng Yu
-
Compact 4G MIMO antenna integrated with a 5G array for current and future mobile handsets
- Author(s): Rifaqat Hussain ; Ali T. Alreshaid ; Symon K. Podilchak ; Mohammad S. Sharawi
-
CPW-fed hexagonal Sierpinski super wideband fractal antenna
- Author(s): Sarthak Singhal and Amit Kumar Singh