Wireless devices such as mobile phones rely on the radio spectrum to send and receive data. There is growing interest in using a worldwide unlicensed spectrum around 60 gigahertz for future wireless applications, but conventional ceramic chip antennas have limited performance at this frequency.
Junfeng Xu and Xianming Qing at the A*STAR Institute for Infocomm Research and co-workers have now developed a ceramic chip antenna that exhibits stable performance in this spectrum. The antenna has a relatively wide bandwidth of 17.1% and a gain of up to 22.1 decibels.
Bandwidth and gain are two of the key indicators for assessing the performance of an antenna. An antenna’s bandwidth specifies the range of frequencies over which its performance does not suffer due to poor impedance matching, and the gain measures the antenna’s ability to convert input power into radiowaves in a specified direction. An ideal antenna must not only be compact and lightweight, but also have a wide bandwidth and high gain, leading to high efficiency.
Conventional antennas have a narrow bandwidth of typically less than 10%, and often require expensive components that present difficult manufacturing challenges, such as embedded air cavities. Instead of re-examining these individual components to improve the performance of the ceramic chip antenna, the researchers focused on three aspects of the overall antenna design.
The design of the radiating elements of the ceramic chip antenna consisted of a compact 8 × 8 cavity array, each made of five vertically stacked layers. The radiating elements alone had a large bandwidth of 23%. The inputs to different portions of the antenna were delivered symmetrically, avoiding distortions in radiation patterns and reductions in bandwidth. The researchers also optimized the connection between an external waveguide at the antenna input and an internal waveguide that delivers the signal to the radiating elements for transmission. The use of an internal waveguide increased the radiative efficiency of the antenna, and the transition element of the connection had a large bandwidth of 19%.
The final size of the constructed antenna was just 47 mm × 31 mm (see image), and a transmission loss of less than 2.5 decibels over an operating bandwidth of 17.1%. The antenna displayed a stable radiation pattern over this operating bandwidth, with a main lobe pointing desirably to the broadside of the antenna. The potential applications of the new ceramic chip include a variety of high-speed and license-free wireless devices, and Xu comments that there are plans to apply the new technology to even higher frequencies above 110 gigahertz.
The A*STAR-affiliated researchers contributing to this research are from the Institute for Infocomm Research.
Xu, J., Chen, Z.N., Qing, X. & Hong, W. Bandwidth enhancement for a 60 GHz substrate integrated waveguide fed cavity array antenna on LTCC. IEEE Transactions on Antennas and Propagation 59 826–832 (2011).
'Super yeast' has the power to improve economics of biofuels
18.10.2016 | University of Wisconsin-Madison
Engineers reveal fabrication process for revolutionary transparent sensors
14.10.2016 | University of Wisconsin-Madison
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences