Graphene‐based angle‐insensitive and tunable single‐band and dual‐band metamaterial terahertz absorber

Author(s):  
Xiaoqing Zhu ◽  
Bo Wang
Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1321
Author(s):  
Wahaj Abbas Awan ◽  
Syeda Iffat Naqvi ◽  
Wael Abd Ellatif Ali ◽  
Niamat Hussain ◽  
Amjad Iqbal ◽  
...  

This paper presents a compact and simple reconfigurable antenna with wide-band, dual-band, and single-band operating modes. Initially, a co-planar waveguide-fed triangular monopole antenna is obtained with a wide operational frequency band ranging from 4.0 GHz to 7.8 GHz. Then, two additional stubs are connected to the triangular monopole through two p-i-n diodes. By electrically switching these p-i-n diodes ON and OFF, different operating frequency bands can be attained. When turning ON only one diode, the antenna offers dual-band operations of 3.3–4.2 GHz and 5.8–7.2 GHz. Meanwhile, the antenna with single-band operation from 3.3 GHz to 4.2 GHz can be realized when both of the p-i-n diodes are switched to ON states. The proposed compact size antenna with dimensions of 0.27λ0 × 0.16λ0 × 0.017λ0 at the lower operating frequency (3.3 GHz) can be used for several wireless applications such as worldwide interoperability for microwave access (WiMAX), wireless access in the vehicular environment (WAVE), and wireless local area network (WLAN). A comparative analysis with state-of-the-art works exhibits that the presented design possesses advantages of compact size and multiple operating modes.


Author(s):  
Anton Sieganschin ◽  
Thomas Jaschke ◽  
Arne F. Jacob

Abstract This contribution deals with a frontend for interleaved receive (Rx)-/transmit (Tx)-integrated phased arrays at K-/Ka-band. The circuit is realized in printed circuit board technology and feeds dual-band Rx/Tx- and single-band Tx-antenna elements. The dual-band element feed is composed of a substrate-integrated waveguide (SIW) diplexer with low insertion loss, a low-noise amplifier (LNA), a bandpass filter, and several passive transitions. The compression properties of the LNA are identified through two-tone measurements. The results dictate the maximum allowable output power of the power amplifier. The single band feed consists of a SIW with several transitions. Simulation and measurement results of the individual components are presented. The frontend is assembled and measured. It exhibits an Rx noise figure of 2 dB, a Tx insertion loss of ~ 2.9 dB, and an Rx/Tx-isolation of 70 dB. The setup represents the unit cell of a full array and thus complies with the required half-wave spacing at both Rx and Tx.


2021 ◽  
Vol 60 (02) ◽  
Author(s):  
Shuaizhao Wang ◽  
Ronghui Xu ◽  
Zujun Qin ◽  
Houquan Liu ◽  
Shijie Deng ◽  
...  

Author(s):  
P. Mukherjee ◽  
E. L. Hines

This chapter focuses on the application of Genetic Algorithms (GAs) techniques in overcoming the limitations of microstrip antennas in terms of several key parameters such as bandwidth, power-handling capacity etc. In this chapter the effectiveness of GAs is discussed in relation to Electromagnetic optimization. A matching network has been designed for single band and dual band matching of microstrip antenna using GA.


2018 ◽  
Vol 10 (12) ◽  
pp. 1909 ◽  
Author(s):  
Yinghui Liu ◽  
Richard Dworak ◽  
Jeffrey Key

Current methods for estimating the surface temperature of sea and lake ice—the ice surface temperature (IST)—utilize two satellite imager thermal bands (11 and 12 μm) at moderate spatial resolution. These “split-window” or dual-band methods have been shown to have low biases and uncertainties. A single-band algorithm would be useful for satellite imagers that have only the 11 μm band at high resolution, such as the Visible Infrared Imaging Radiometer Suite (VIIRS), or that do not have a fully functional 12 μm band, such as the Thermal Infrared Sensor onboard the Landsat 8. This study presents a method for single-band IST retrievals, and validation of the retrievals using IST measurements from an airborne infrared radiation pyrometer during the NASA IceBridge campaign in the Arctic. Results show that IST with a single thermal band from the VIIRS has comparable performance to IST with the VIIRS dual-band (split-window) method, with a bias of 0.22 K and root-mean-square error of 1.03 K.


2019 ◽  
Vol 61 (11) ◽  
pp. 2586-2590
Author(s):  
Ali Kursad Gorur ◽  
Pinar Ozturk Ozdemir ◽  
Ceyhun Karpuz ◽  
Adnan Gorur

Author(s):  
Yiqun Li Yiqun Li ◽  
B. Derat ◽  
T. Cantin ◽  
O. Tiennault ◽  
J. De Oliveira ◽  
...  
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