scholarly journals Highly Directional Small-Size Antenna Designed with Homogeneous Transformation Optics

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Zuojia Wang ◽  
Lian Shen ◽  
Jun Chen ◽  
Huaping Wang ◽  
Faxin Yu ◽  
...  
Keyword(s):  
Coordinate Transformation ◽  
Regular Polygon ◽  
Virtual Space ◽  
Transformation Optics ◽  
Antenna Design ◽  
Radiation Patterns ◽  
Antenna Aperture ◽  
Material Parameters ◽  
Large Size

Achieving high directivity antenna usually requires a large size antenna aperture in traditional antenna design. Previous work shows that, with the help of metamaterials and transformation optics, a small size antenna can perform as high directivity as a large size antenna, but the material parameters are inhomogeneous and difficult to realize. In this paper, we propose a linear homogeneous coordinate transformation to design the small size antenna. Distinguishing from inhomogeneous transformation, we construct a regular polygon in virtual space and then divide it into several triangle segments. By applying linear homogeneous coordinate transformation, the antenna devices can be greatly compressed without disturbing the radiation patterns by using homogeneous metamaterial substrates. The material parameters of the antenna designed from this method are homogeneous and easy to fabricate. Square and hexagonal antenna structures are numerically demonstrated to illustrate the validity of our methodology.

scholarly journals Revealing topology with transformation optics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lizhen Lu ◽  
Kun Ding ◽  
Emanuele Galiffi ◽  
Xikui Ma ◽  
Tianyu Dong ◽  
...  
Keyword(s):  
Physical Space ◽  
Real Space ◽  
Virtual Space ◽  
Transformation Optics ◽  
Coordinate Space ◽  
Dimensional System ◽  
Edge States ◽  
And Topology ◽  
Higher Dimensional ◽  
Insight Into

AbstractSymmetry deepens our insight into a physical system and its interplay with topology enables the discovery of topological phases. Symmetry analysis is conventionally performed either in the physical space of interest, or in the corresponding reciprocal space. Here we borrow the concept of virtual space from transformation optics to demonstrate how a certain class of symmetries can be visualised in a transformed, spectrally related coordinate space, illuminating the underlying topological transitions. By projecting a plasmonic system in a higher-dimensional virtual space onto a lower-dimensional system in real space, we show how transformation optics allows us to construct a topologically non-trivial system by inspecting its modes in the virtual space. Interestingly, we find that the topological invariant can be controlled via the singularities in the conformal mapping, enabling the intuitive engineering of edge states. The confluence of transformation optics and topology here can be generalized to other wave realms beyond photonics.

scholarly journals A Printed Yagi Antenna for CubeSat with Multi-Frequency Tilt Operation

Electronics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 986 ◽  
Author(s):  
Sining Liu ◽  
Raad Raad ◽  
Panagiotis Ioannis Theoharis ◽  
Faisel Em Tubbal
Keyword(s):  
High Gain ◽  
Antenna Design ◽  
Radiation Patterns ◽  
Printed Antenna ◽  
General Theme ◽  
Yagi Antenna ◽  
L Band ◽  
Functional States

In this paper, a printed Yagi antenna with an integrated balun is proposed for CubeSat communications. The printed antenna is mechanically adjustable to realize three functional states at different operating frequencies in the L-band and S-band respectively. Three different angle deployments are proposed at 10°, 50° and 90°, so that the antenna operates at three different operating frequencies, namely 1.3 GHz (L-band), 2.4 GHz (S-band) and 3 GHz (S-band). The measured results of the fabricated antenna are well matched with the simulation, having frequencies of 2.82–3.07 GHz, 1.3–1.4 GHz and 2.38–2.57 GHz, with similar radiation patterns. The measured gain of the antenna is 8.167 dBi at 2.4 GHz, 5.278 dBi at 1.3 GHz and 6.120 dBi at 3 GHz. Keeping within the general theme of cheap off the shelf components for CubeSats, this antenna design allows the CubeSat designers to choose from three popular frequencies, through a simple angle configuration. The main contribution of this work lies with the reconfigurable frequency, relatively high gain and simplicity of design.

Compact Dual-Band Proximity-Fed Circularly Polarized Patch Antenna for BDS Applications

Frequenz ◽  
2015 ◽  
Vol 69 (9-10) ◽  
Author(s):  
Jianxing Li ◽  
Bin He ◽  
Jing Fang ◽  
Anxue Zhang
Keyword(s):  
Patch Antenna ◽  
Branch Length ◽  
Axial Ratio ◽  
Dielectric Substrate ◽  
Satellite System ◽  
Antenna Design ◽  
Dual Band ◽  
Antenna Aperture ◽  
Small Surface ◽  
Circularly Polarized

AbstractThis paper presents a compact dual-band proximity-fed circularly polarized (CP) patch antenna for BeiDou Navigation Satellite System (BDS) operation at B1 (1,561 MHz) and B3 (1,268 MHz) bands. The antenna aperture is minimized down to 26.6 mm (λ/9 at the B3 band) in diameter and 12 mm (λ/20 at the B3 band) in thickness using high permittivity dielectric substrate and meandered slots. The antenna design features that the resonant frequency in the higher band could be tuned independently by adjusting the branch length and breadth without affecting the lower band. To achieve right-handed CP (RHCP) radiation property, quadrature phase feeding is employed together with a broadband 0°–90° hybrid utilizing a small surface mount LTCC hybrid coupler chip. Experimental results show that the RHCP gain maintains larger than 1.5 dBic and the axial ratio (AR) stays below 3 dB within the B1 and B3 bands. This antenna design is a promising candidate for small BDS arrays as well as other dual-band BDS applications.

scholarly journals Non-contact method to freely control the radiation patterns of antenna with multi-folded transformation optics

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Hamza Ahmad Madni ◽  
Bin Zheng ◽  
Rongrong Zhu ◽  
Lian Shen ◽  
Hongsheng Chen ◽  
...  
Keyword(s):  
Transformation Optics ◽  
Contact Method ◽  
Radiation Patterns

scholarly journals Development of Microstrip Antenna for Satellite Application at Ku/Ka Band

2021 ◽  
pp. 118-125
Author(s):  
Farooq Al-Janabi ◽  
◽  
Mandeep Jit Singh ◽  
Amar Partap Singh Pharwaha
Keyword(s):  
Microstrip Antenna ◽  
Electromagnetic Waves ◽  
Electrical Signal ◽  
Antenna Design ◽  
Dual Band ◽  
Ka Band ◽  
Large Size ◽  
Narrow Bandwidth ◽  
Almost All ◽  
Ku Band

Antennas are the most important unit in almost all wireless communications, which played the key of transmitting the radiating electromagnetic waves after converting it from electrical signal. In this paper, designed an antenna that is capable to operate at frequencies between 12 GHz – 18 GHz for Ku band, and 26.5 GHz – 40 GHz for Ka band. This antenna was designed to overcome the narrow bandwidth, low gain, and large size of most satellite application antennas. By using a square shaped patch on a 4.3 dielectric constant substrate, modified and optimized the dimensions of the patch element, this antenna operated on dual-band frequencies between 12 GHz – 18 GHz and 26.5 GHz – 40 GHz, which satisfies the required bandwidth for satellite application. The antenna design was simulated using CST Microwave Studio software to analyze and evaluate the performance of the antenna design visibility.

scholarly journals Robustly printable freeform thermal metamaterials

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wei Sha ◽  
Mi Xiao ◽  
Jinhao Zhang ◽  
Xuecheng Ren ◽  
Zhan Zhu ◽  
...  
Keyword(s):  
A Priori ◽  
Transformation Optics ◽  
A Priori Knowledge ◽  
Flexible Design ◽  
Material Parameters ◽  
Fast Prototyping ◽  
Complex Shapes ◽  
Design Paradigm ◽  
Background Temperature ◽  
3D Printed

AbstractThermal metamaterials have exhibited great potential on manipulating, controlling and processing the flow of heat, and enabled many promising thermal metadevices, including thermal concentrator, rotator, cloak, etc. However, three long-standing challenges remain formidable, i.e., transformation optics-induced anisotropic material parameters, the limited shape adaptability of experimental thermal metadevices, and a priori knowledge of background temperatures and thermal functionalities. Here, we present robustly printable freeform thermal metamaterials to address these long-standing difficulties. This recipe, taking the local thermal conductivity tensors as the input, resorts to topology optimization for the freeform designs of topological functional cells (TFCs), and then directly assembles and prints them. Three freeform thermal metadevices (concentrator, rotator, and cloak) are specifically designed and 3D-printed, and their omnidirectional concentrating, rotating, and cloaking functionalities are demonstrated both numerically and experimentally. Our study paves a powerful and flexible design paradigm toward advanced thermal metamaterials with complex shapes, omnidirectional functionality, background temperature independence, and fast-prototyping capability.

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