scholarly journals Waveguide divider design based on null of electric field

Author(s):  
Leonardo Zappelli

AbstractNowadays, the design of dividers is based on electromagnetic software that optimizes some geometric parameters to obtain the required performance. The choice of the geometry of the discontinuities contained in the divider and of the optimization initial point is quite critical to satisfy the divider requirements. In the last years, it is quite rare to find in the literature a theoretical approach helping the designers in the choice of the divider geometry. Helpful suggestion can derive by the analysis of the electric field in a trial divider that satisfies power division among the output ports in a thin band. In fact, the electric field null can be filled with metallic septa that ensure the same behavior at any frequency. The optimization of the septa position/form with numerical electromagnetic software permits to obtain divider with large bandwidth. A further analysis of the electric field null in the divider permits to add lateral metallic septa that further enlarge the transmission band. Finally, the design of an input matching network increases the transmitted power to the desired value.

2021 ◽  
Author(s):  
Jianjun LI ◽  
Qiu-Xiang Qin ◽  
Guo-Jun Weng ◽  
Jian Zhu ◽  
Jun-Wu Zhao

Abstract In this study, the nanoboxes is converted into Au-Ag alloy nanocages by increasing the hole size. Discrete dipole approximation (DDA) is used to study the extinction spectrum and the refractive index sensing characteristics of Au-Ag alloy nanocages with different geometric parameters. With the increase of Au component, the local surface plasmon resonance (LSPR) peak shows approximately linear redshift and the sensitivity factor shows approximately linear decrease. The refractive index sensitivity can be effectively controlled by the Au-Ag ratio at large hole size because the hole and cavity surfaces distribute more environmental dielectric components. Therefore, increasing the hole size and decreasing the Au-Ag ratio can improve the refractive index sensitivity. To explain the effect of alloy composition on the LSPR characteristics and the refractive index sensitivity, the local electric field distributions with different geometric parameters are plotted. We find that the electric field direction on the hole and cavity surfaces are controlled by the Au-Ag ratio and environmental dielectric constant. Moreover, the field vector on the hole and cavity surfaces are formed by the superposition of the incident field, the electric field generated by the oscillating electrons on the outer surface, and the polarized field in the environmental dielectric constant.


Author(s):  
Anjana Jyothi Banu ◽  
G. Kavya ◽  
D. Jahnavi

A 26[Formula: see text]GHz low-noise amplifier (LNA) designed for 5G applications using 0.18[Formula: see text][Formula: see text]m CMOS technology is proposed in this paper. The circuit includes a common-source in the first stage to suppress the noise in the amplifier. The successive stage has a Cascode topology along with an inductive feedback to improve the power gain. The input matching network is designed to achieve the input reflection coefficient less than [Formula: see text]7dB at the intended frequency. The matching network at the output is designed using inductor–capacitor (LC) components connected in parallel to attain the output reflection coefficient of [Formula: see text]10[Formula: see text]dB. Due to the inductor added in feedback at the second stage. The [Formula: see text] obtained is 18.208[Formula: see text]dB at 26[Formula: see text]GHz with a noise figure (NF) of 2.8[Formula: see text]dB. The power supply given to the LNA is 1.8[Formula: see text]V. The simulation and layout of the presented circuit are performed using Cadence Virtuoso software.


2020 ◽  
Vol 22 (35) ◽  
pp. 19957-19968
Author(s):  
Supriya Ghosal ◽  
Arka Bandyopadhyay ◽  
Debnarayan Jana

Transverse electric field breaks the sublattice symmetry and generates a band gap in the semi-metallic T-Ge structure.


2020 ◽  
Vol 29 (11) ◽  
pp. 2020006
Author(s):  
Tian Qi ◽  
Songbai He ◽  
Cheng Zhong ◽  
Zhitao Zhu

In this paper, the design of a wideband monolithic microwave integrated circuit (MMIC) low-noise amplifier (LNA) fabricated in 0.13-[Formula: see text]m GaAs pHEMT process is presented. A simple T-type input matching network (IMN) and a source feedback structure are employed to achieve low noise figure (NF). The MMIC LNA, which operates across 12–18[Formula: see text]GHz, can be used for satellite applications. Experimental results show an NF around 1.5[Formula: see text]dB in 12–17.5[Formula: see text]GHz and a minimum NF of 1.21[Formula: see text]dB at 16.5[Formula: see text]GHz. In addition, a flat small-signal gain of [Formula: see text][Formula: see text]dB is achieved at 13.5–17.5[Formula: see text]GHz. The input return loss is lower than [Formula: see text] dB at 12–14.5[Formula: see text]GHz and the output return loss is lower than [Formula: see text] dB at 12–17[Formula: see text]GHz. The power consumed is lower than 0.3[Formula: see text]W and the [Formula: see text] (1-dB compression point) output power is around 13[Formula: see text]dBm.


Integration ◽  
2016 ◽  
Vol 52 ◽  
pp. 323-333 ◽  
Author(s):  
A. Saberkari ◽  
Sh Kazemi ◽  
V. Shirmohammadli ◽  
M.C.E. Yagoub

1995 ◽  
Author(s):  
Valter Cocco ◽  
Piero Marietti ◽  
Giuseppe Torino ◽  
Alessandro Trifiletti ◽  
Giuliano Gatti

2011 ◽  
Vol 58 (8) ◽  
pp. 482-486 ◽  
Author(s):  
Hongrui Wang ◽  
Lei Zhang ◽  
Li Zhang ◽  
Yan Wang ◽  
Zhiping Yu

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