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E-Shape Top-Loaded Octagonal Patch Antenna for Small-Frequency Applications
Published in T. Kishore Kumar, Ravi Kumar Jatoth, V. V. Mani, Electronics and Communications Engineering, 2019
P. Venu Madhav, M. Sivaganga Prasad
The imitation tool is used in evaluating the performance of the antenna which is established on the method of moment’s technique and used for computing VSWR, return loss, and gain of the suggested antenna. The return loss specifies the volume of power that is lost to load and does not return as reflection. Figure 5.5 shows that during the first stage, the antenna shows a return loss above 10 GHz and later after stage 4, the antenna is able to be operated in multiple bands ranging from 1.9 to 2.4 GHz, 2.9 to 3.2 GHz, and 5.3 to 6 GHz. Table 5.1 shows that as the stage increases, the fundamental frequency is shifted to the lower side and is suitable for multiband applications. The patch-covering geometries were inspected ideally, and reasonable values of resonant frequency, return loss, and gain are inspected and related. The comparative table shows that final patch which gives decent results in contrast with stage progress. It is observed that the antenna has minimum VSWR, progress in reflection coefficient, three frequency bands with considerable bandwidth, and gain.
Testing Coaxial Transmission Line
Published in Jerry C. Whitaker, The RF Transmission Systems Handbook, 2017
Ideally, the measurements should be used to confirm a good impedance match, which can be interpreted as minimum VSWR or maximum return loss. Return loss is related to the level of signal that is returned to the input connector after the signal has been applied to the transmission line and reflected from the load. A line perfectly matched to the load would transfer all energy to the load. No energy would be returned, resulting in an infinite return loss, or an ideal VSWR of 1:1. The benefits of matching the transmission line system for minimum VSWR include: Most efficient power transfer from the transmitter to the antenna systemBest performance with regard to overall bandwidthImproved transmitter stability with tuning following accepted procedures more closelyMinimum transmitted signal distortions
Fundamentals of an Antenna
Published in Rajveer S. Yaduvanshi, Gaurav Varshney, Nano Dielectric Resonator Antennas for 5G Applications, 2020
Rajveer S. Yaduvanshi, Gaurav Varshney
Return loss is the measure of the closeness between the input impedance of the network and the overall impedance of the system. () RLin=−20log10|S11|dB
Design and development of T-Shaped antenna structure for wireless communication
Published in Waves in Random and Complex Media, 2022
The circumstance calls for a passive AUT. With active devices, a negative return loss is conceivable. The efficiency of power distribution from a transmission line to a load, such an antenna, is measured by return loss. It is a positive non-dissipative phrase that describes the decrease in wave amplitude between the incident and reflected waves. The differential between the power consequent is upon a discontinuity in a transmission system. The power incident upon the discontinuity divided by the power reflected from the discontinuity, expressed in dB. Note that this proportion is also the square of the reciprocal of the reflection coefficient's magnitude. More specifically, the return loss is the number of decibels that corresponds to the scalar value of the reciprocal of the reflection coefficient, and it is a measure of the difference between two impedances. When the reflection is minor, return loss is an efficient technique to describe mismatch. The concepts of return loss beginnings are unclear, but it seems that the Smith chart acceptance is connected to how it is used in microwaves and antennas.
Performance Analysis of Radio Over Fiber System Employing Photonics Antenna and Different Modulation Schemes
Published in IETE Journal of Research, 2023
From simulation results obtained from Ansys HFSS 19 software, the antenna has a radiation pattern, as shown in Figure 5(a) which depicts the gain as almost 3 dBi. Radiation pattern can be defined as the energy radiated by the antenna. It is basically the graphical representation of the energy radiated into space. A return loss of −21 dB at 2.4 GHz (which is mainly used for WLAN applications) can be seen from Figure 5(b). Return loss is basically the reflection loss which is loss in power of the signal returned or reflected by the transmission line due to discontinuity.
Frequency modulated thermal wave imaging for visualizing power density of electromagnetic waves on plane surfaces
Published in Research in Nondestructive Evaluation, 2019
Khalid Muzaffar, Deboshree Roy, Suneet Tuli, Shiban Koul
It is worth to mention that the return loss of an antenna represents the fraction of the RF input power reflected back. Return loss is a measure of the effectiveness of power delivery from a transmission line to a load such as an antenna. This parameter should be low at the operating frequency for an antenna system so that the RF power fed to the antenna is actually delivered to it and not reflected back. The return loss plots obtained from simulation (CST Microwave Studio) and measurement (Vector Network analyzer) are shown in Figure 8(b).