scholarly journals Considerations for the Design of UWB Antennas for Mobile and Consumer Equipment

2005 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Dirk Manteuffel

This paper presents some considerations on the design, characterization and optimization of UWB (Ultra WideBand) antennas for consumer communication equipment. As a first step a method to extract the spatio-temporal UWB antenna characterization from a FDTD simulation is given. Thereafter, the shape of a planar monopole is optimized to provide broadband matching. This is followed by the integration of latter antenna into a model of a DVD player and the impact of this integration on the antenna performance is evaluated. Finally, the transfer function of the complete system is extracted and used for indoor propagation modeling in an exemplary living home environment. The results show that the antenna integration into the DVD-chassis results into a directive radiation pattern that shows a significant frequency dependency. When this antenna is used for the propagation modeling, a single frequency ray-tracing simulation shows significant variation in the radiated power distribution in the room as a result of the directive pattern. When the received power is averaged over a larger bandwidth, the coverage becomes more smooth mainly due to the frequency dependency of the radiation pattern and frequency dependent propagation effects. Indeed, comparing the results of the integrated antenna to the case of the ideal isotropic radiator, no major disadvantages can be discerned anymore.

2020 ◽  
Vol 10 (2) ◽  
pp. 504 ◽  
Author(s):  
Halgurd N. Awl ◽  
Yadgar I. Abdulkarim ◽  
Lianwen Deng ◽  
Mehmet Bakır ◽  
Fahmi F. Muhammadsharif ◽  
...  

In this work, the impact of substrate type and design dimensions on bow-tie microstrip antenna performance and bandwidth improvement is presented both numerically and experimentally at 4–8 GHz. The finite integration technique (FIT)-based high-frequency electromagnetic solver, CST Microwave Studio, was used for the simulation analysis. For this purpose, four bow-tie microstrip antennas were designed, fabricated, and measured upon using different materials and substrate thicknesses. Precise results were achieved and the simulated and experimental results showed a good agreement. The performance of each antenna was analyzed and the impact of changing material permittivity, antenna dimensions and substrate thicknesses on antenna performance were investigated and discussed. The measured results indicated that the slot bow-tie antenna, which is one of the novel aspects of this study, is well matched and a 2-GHz bandwidth [5–7 GHz] is obtained, which is about 50% bandwidth in comparison with the wideband applications [4–8 GHz]. The proposed structure is useful in ultra-wideband (UWB) applications. This study provides guidance in selecting material types and thicknesses for microstrip antennas based on desired applications.


2018 ◽  
Vol 7 (4.30) ◽  
pp. 403
Author(s):  
Abdul Rashid .O. Mumin ◽  
R. Alias ◽  
Jiwa Abdullah ◽  
Raed A Abdulhasan ◽  
Samsul Haimi Dahlan ◽  
...  

Performance characteristics of head-worn antenna based on dielectric substrate for WBAN application with various dielectric constant for square slot patch antenna are demonstrated in this paper. The impact of Electromagnetic (EM) energy from antenna towards human head and on antenna performance changes due to human head proximity are explored in this paper. The human head exposed to 5.8 GHz on ISM frequency band and radiation pattern, return loss, efficiency, and bandwidth and SAR distribution value performance have been thoroughly explored. However, decreasing the antenna size is a great topic ‎of antenna development, which differentiates antenna performance for a small antenna. Multilayered human head phantom having five layers are constructed based on different tissues and these tissues represent human head parts such as (Skin, fat, Cerebrospinal fluid (CSF), bone and brain), all of each tissues are based on their electromagnetic properties and set at 5.8GHz.The proposed antenna with human head model simulated through (FDTD) using CST and variation of parameters of antenna with MATLAB.  Antenna with FR4 substrate produces the highest SAR values while antenna with RT5880 substrate has the lowest SAR value 0.206 W/kg and 0.0784 W/kg at 5.8 GHz frequency exposed for 10g tissue respectively. It can be observed that the radiation pattern shows that the antenna gain with substrate of Rogers RT5880 is increased from front –to-back from 7.1 to 7.29 dB in the free space and on human head respectively. A good agreement between simulation and measurements in free space are obtained. The presented prototype has a potential to work for ISM applications.


Author(s):  
Anas Khan

This review paper investigates the impact of lightning segmented diverter strips on radome-antenna performance. A brief overview is given and the admissible length of strips is calculated. The effects of using a nose radome on the antenna performance is also calculated. Three models, namely Physical Optics (PO) model and two computational models, FEKO and Shako, that work using Method of Moments are used and Radiation pattern results are compared


2017 ◽  
Vol 25 (19) ◽  
pp. 22805 ◽  
Author(s):  
Yinlu Wang ◽  
Ming Chen ◽  
Jin-Yuan Wang ◽  
Jianfeng Shi ◽  
Zhaohui Yang ◽  
...  

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Haixia Liu ◽  
Fei Wang ◽  
Yang Yang ◽  
Xiaowei Shi ◽  
Long Li

With the trend of the miniaturization, broadband, and integration of multisystems of wireless communication terminals, a new ultrawideband planar inverted-F antenna (PIFA) with capacitive ground plane is proposed in this paper. The capacitive ground plane is composed of a sheet of metal islands, which makes a major contribution to ultra-wideband from 2.3 GHz to 9.0 GHz by applying the capacitive compensation for input impedance of the PIFA in high-order modes frequency bands. The effect of geometric parameters of capacitive ground plane and antenna height on antenna performance is analyzed. It is found that the radiation pattern in free space and the gain of the proposed antenna also meet the demands of the wireless communication terminals. The reported antenna was fabricated and measured, and the experimental results are in good agreement with the simulation results.


Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 780
Author(s):  
Kazunori Takahashi ◽  
Takashi Miwa

The paper discusses a way to configure a stepped-frequency continuous wave (SFCW) radar using a low-cost software-defined radio (SDR). The most of high-end SDRs offer multiple transmitter (TX) and receiver (RX) channels, one of which can be used as the reference channel for compensating the initial phases of TX and RX local oscillator (LO) signals. It is same as how commercial vector network analyzers (VNAs) compensate for the LO initial phase. These SDRs can thus acquire phase-coherent in-phase and quadrature (I/Q) data without additional components and an SFCW radar can be easily configured. On the other hand, low-cost SDRs typically have only one transmitter and receiver. Therefore, the LO initial phase has to be compensated and the phases of the received I/Q signals have to be retrieved, preferably without employing an additional receiver and components to retain the system low-cost and simple. The present paper illustrates that the difference between the phases of TX and RX LO signals varies when the LO frequency is changed because of the timing of the commencement of the mixing. The paper then proposes a technique to compensate for the LO initial phases using the internal RF loopback of the transceiver chip and to reconstruct a pulse, which requires two streaming: one for the device under test (DUT) channel and the other for the internal RF loopback channel. The effect of the LO initial phase and the proposed method for the compensation are demonstrated by experiments at a single frequency and sweeping frequency, respectively. The results show that the proposed method can compensate for the LO initial phases and ultra-wideband (UWB) pulses can be reconstructed correctly from the data sampled by a low-cost SDR.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3803
Author(s):  
Chan-Mi Song ◽  
Hong-Jun Lim ◽  
Son Trinh-Van ◽  
Kang-Yoon Lee ◽  
Youngoo Yang ◽  
...  

In this paper, a dual-band RF wireless power transfer (WPT) system with a shared-aperture dual-band Tx array antenna for 2.4 and 5.8 GHz is proposed. The final configuration of the Tx array, which is made up of 2.4 GHz right-handed circular polarization (RHCP) patches and 5.8 GHz RHCP patches, is derived from the optimization of 2.4 and 5.8 GHz thinned arrays, ultimately to achieve high transmission efficiency for various WPT scenarios. The dual-band RF WPT Tx system including the Tx array antenna and a Tx module is implemented, and Rx antennas with a 2.4 GHz patch, a 5.8 GHz patch, and a dual-band (2.4 and 5.8 GHz) patch are developed. To validate the proposed dual-band RF WPT system, WPT experiments using a single band and dual bands were conducted. When transmitting RF wireless power on a single frequency (either 2.482 GHz or 5.73 GHz), the received power according to the distance between the Tx and Rx and the position of the Rx was measured. When the distance was varied from 1 m to 3.9 m and the transmitted power was 40 dBm, the received power value at 2.482 GHz and 5.73 GHz were measured and found to be 24.75–13.5 dBm (WPT efficiency = 2.985–0.224%) and 19.25–6.8 dBm (WPT efficiency = 0.841–0.050%), respectively. The measured results were in good agreement with the calculated results, and it is revealed that the transmission efficiency when wireless power is transmitted via beam-focusing increases more than that with conventional beam-forming. Furthermore, the dual-band WPT experiment proves that 2.482 GHz beam and 5.73 GHz beams can be formed individually and that their wireless power can be transmitted to a dual-band Rx or two different Rx.


2020 ◽  
Vol 11 (1) ◽  
pp. 104
Author(s):  
Peipei Dai ◽  
Jianping Xing ◽  
Yulong Ge ◽  
Xuhai Yang ◽  
Weijin Qin ◽  
...  

The timing group delay parameter (TGD) or differential code bias parameter (DCB) is an important factor that affects the performance of GNSS basic services; therefore, TGD and DCB must be taken seriously. Moreover, the TGD parameter is modulated in the navigation message, taking into account the impact of TGD on the performance of the basic service. International GNSS Monitoring and Assessment System (iGMAS) provides the broadcast ephemeris with TGD parameter and the Chinese Academy of Science (CAS) provides DCB products. In this paper, the current available BDS-3 TGD and DCB parameters are firstly described in detail, and the relationship of TGD and DCB for BDS-3 is figured out. Then, correction models of BDS-3 TGD and DCB in standard point positioning (SPP) or precise point positioning (PPP) are given, which can be applied in various situations. For the effects of TGD and DCB in the SPP and PPP solution processes, all the signals from BDS-3 were researched, and the validity of TGD and DCB has been further verified. The experimental results show that the accuracy of B1I, B1C and B2a single-frequency SPP with TGD or DCB correction was improved by approximately 12–60%. TGD will not be considered for B3I single-frequency, because the broadcast satellite clock offset is based on the B3I as the reference signal. The positioning accuracy of B1I/B3I and B1C/B2a dual-frequency SPP showed that the improvement range for horizontal components is 60.2% to 74.4%, and the vertical components improved by about 50% after the modification of TGD and DCB. In addition, most of the uncorrected code biases are mostly absorbed into the receiver clock bias and other parameters for PPP, resulting in longer convergence time. The convergence time can be max increased by up to 50% when the DCB parameters are corrected. Consequently, the positioning accuracy can reach the centimeter level after convergence, but it is critical for PPP convergence time and receiver clock bias that the TGD and DCB correction be considered seriously.


Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4717 ◽  
Author(s):  
Sylvester Johansson ◽  
Jonas Persson ◽  
Stavros Lazarou ◽  
Andreas Theocharis

Social considerations for a sustainable future lead to market demands for electromobility. Hence, electrical power distribution operators are concerned about the real ongoing problem of the electrification of the transport sector. In this regard, the paper aims to investigate the large-scale integration of electric vehicles in a Swedish distribution network. To this end, the integration pattern is taken into consideration as appears in the literature for other countries and applies to the Swedish culture. Moreover, different charging power levels including smart charging techniques are examined for several percentages of electric vehicles penetration. Industrial simulation tools proven for their accuracy are used for the study. The results indicate that the grid can manage about 50% electric vehicles penetration at its current capacity. This percentage decreases when higher charging power levels apply, while the transformers appear overloaded in many cases. The investigation of alternatives to increase the grid’s capabilities reveal that smart techniques are comparable to the conventional re-dimension of the grid. At present, the increased integration of electric vehicles is manageable by implementing a combination of smart gird and upgrade investments in comparison to technically expensive alternatives based on grid digitalization and algorithms that need to be further confirmed for their reliability for power sharing and energy management.


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