Showing papers on "GSM frequency bands published in 2020"

Antenna Optimization Design Based on Deep Gaussian Process Model

Abstract: When using Gaussian process (GP) machine learning as a surrogate model combined with the global optimization method for rapid optimization design of electromagnetic problems, a large number of covariance calculations are required, resulting in a calculation volume which is cube of the number of samples and low efficiency. In order to solve this problem, this study constructs a deep GP (DGP) model by using the structural form of convolutional neural network (CNN) and combining it with GP. In this network, GP is used to replace the fully connected layer of the CNN, the convolutional layer and the pooling layer of the CNN are used to reduce the dimension of the input parameters and GP is used to predict output, while particle swarm optimization (PSO) is used algorithm to optimize network structure parameters. The modeling method proposed in this paper can compress the dimensions of the problem to reduce the demand of training samples and effectively improve the modeling efficiency while ensuring the modeling accuracy. In our study, we used the proposed modeling method to optimize the design of a multiband microstrip antenna (MSA) for mobile terminals and obtained good optimization results. The optimized antenna can work in the frequency range of 0.69–0.96 GHz and 1.7–2.76 GHz, covering the wireless LTE 700, GSM 850, GSM 900, DCS 1800, PCS1900, UMTS 2100, LTE 2300, and LTE 2500 frequency bands. It is shown that the DGP network model proposed in this paper can replace the electromagnetic simulation software in the optimization process, so as to reduce the time required for optimization while ensuring the design accuracy.

Band-stop filter design based on split ring resonators loaded on the microstrip transmission line for GSM-900 and 2.4 GHz ISM band

Abstract: Split-ring resonator is a popular research topic in literature. As known, it may be used in the design of electromagnetic metamaterials. Additionally, these structures can be preferred in microwave filter devices. In this study, a band-stop filter was designed for GSM-900 and 2.4 GHz ISM band by using split-ring resonators. Two split-ring arrays (sizes of one of these arrays were larger than the other) were loaded on the transmission line and each array consisted of four identical rings. Thus, a dual-band pass filter was obtained and this filter covered the frequency of 0.91 (GSM) and 2.43 (ISM) GHz. Then, this proposed design was fabricated and measured. According to the measurement results, the fabricated structure operated at 0.93 GHz and 2.47. The experimental results were consistent with the simulation results. As a result, thanks to the proposed structure, two frequencies can be stopped at the same time. There is no need to design a different filter structure for each frequency.

Defected Ground Structured Wideband Antenna for RF Energy Harvesting

Abstract: This work addresses the design of dual side printed antenna using defected ground structure (DGS) for RF energy harvesting system. Proposed antenna acquires RF energy from all the available directions. This system harvests the energy between 1GHz to 5GHz. The antenna shows better directivity and return loss response at the major operating bands such as 1.9GHz (GSM Bands), 2.4GHz-2.6GHz (Bluetooth/WLAN), 3.2GHz (Third generation), and 3.5GHz-3.6GHz (for LTE/4G). The overall layout of the antenna is 41 mm (L) x 45 mm (W). The proposed antenna maintains a compact antenna size and wideband frequency response to harvest the RF power when the position of the source is not known.

Assessing the risk associated with simultaneous exposure to mobile communication signals within 900–2500 mhz in nigeria

Abstract: In this study, the total exposure due to signals within GSM 900, GSM 1800, CDMA-1900 and 3G-2100 frequency bands at 200 m from the foot of 120, 100 and 80 base station masts in the Nigerian cities of Lagos, Ibadan and Abuja, respectively, was assessed. A calibrated hand-held spectrum analyser was used to measure the level of power (in dBm) of each signal within the mobile frequency bands. The exposure quotient associated with the combine electric field strengths from the various frequency bands in each city was estimated. The maximum value of total electric field strength at each point in Lagos, Ibadan and Abuja was 0.83 V/m, 0.53 V/m and 1.63 V/m, respectively. This study shows that the exposure quotient due to the simultaneous exposure to the four bands of mobile communication signals in each city is far less than one, as recommend by International Commission on Non-Ionizing Radiation Protection.

Sigma-Structured Microstrip Antenna for Harvesting Energy for Low-Power Devices

Abstract: In the usage of microelectronic components such as sensors, generally small size cell is required and it needs replacement time to time when the cell is discharged. Here it can be predicted the theoretical analysis to operate the small sensors without replacing cells by using rectenna. This is the best alternative for the operation of low-power microelectronic components. In this paper, the sigma-structured antenna is used which is able to operate in two frequencies which are 0.96 and 2.12 GHz. In this regard, it has been analyzed the amount of received power at 0.96 GHz frequency.

Design and Analysis of Modified E-Shape Multiband Patch Antenna for Wireless Applications

Abstract: Recent developments of the Wireless communication requires multi band, high gain, and bandwidth. In This paper, E-Shape fractal antenna is simulated and fabricated with different iterations which provide low profile and high gain to support Wireless applications. Proposed antenna operates in the range of 0.85 GHz–2.5 GHz. The structure is simulated using CADFEKO 14.0 software, and experimental results have been analyzed using a vector network analyzer. Designed antenna achieved the multiband characteristics for three different bands 0.9142–1.023 GHz, 1.74–2.064 GHz, 2.198–2.522 GHz which are suitable for GSM 900, UMTS 1800/1900, and LTE 2300/2500 applications.

A Novel Electronically Reconfigurable Antenna Design for RFID and GSM 900 MHz Applications

Abstract: In microwave systems, frequency tunable planar antennas have become common place as it is increasingly difficult to cover all the necessary frequency bands required. These antennas are low profile, conformable to planar and nonplanar surfaces, simple and inexpensive to manufacture using modern printed-circuit technology. The work presented in this paper proposes a electronically reconfigurable planar antenna by using only one varactor diode. Varactor diode from Skyworks Solutions Inc. (SVM1251) has been used as tuning element. It provides a tunable capacitance range from 53.65 to 2.79 pF with reverse voltages varying between 0 and 8 V. A 50 Ohm resistor as dummy load, and two 68 pF SMD capacitors are incorporated within the structure in order to protect the DC supply to Network Vector Analyzer from dc current, in addition to having an effect on the size reduction. Proposed antenna operate frequency between 400 MHz and 1116 MHz that include ultra-high frequency (UHF) for radio frequency identification (RFID) and Global Systems for Mobile Communications (GSM) applications. Proposed compact antenna having the overall physical size of 8 mm x 8 mm (0.0203λ x 0.0203 λ) is numerically modeled on FR4 substrate having loss tangent, dielectric constant and height of 0.025, 4.3, and 1.61 mm respectively in the CST Microwave Studio numerical calculation program over the frequency range from 300 MHz to 1.5 GHz. The proposed electrically tunable directional antenna has better return loss level higher than 25 dB with reduced size with novel geometrical structure in the operating frequency between 400 to 1116 MHz.

Design of a Printed Metamaterial-Inspired Electrically Small Huygens Source Antenna for Cognitive Radio Applications

Abstract: Metamaterial-inspired electric- and magneticbased near-field resonant parasitic (NFRP) elements are electrically coupled to a coaxial-fed printed monopole to realize an electrically small, ka = 0.49 (λₒ/9.41 x λₒ/14.11 x λₒ/104.18) Huygens source antenna that operates at the GSM1800 frequency. The electric NFRP element is a meander patch; the magnetic element is a Capacitively Loaded Loop (CLL). The individual electric- and magnetic-based antennas were studied numerically to ensure they had overlapping frequency behavior near the GSM frequency 1.8 GHz; high radiation efficiency; and very good matching to their 50 Ω sources. They were combined together and retuned to create a three metal – two dielectric layer Huygens source antenna. A 20 nH inductor was inserted between the driven monopole and the SMA connector in order to enhance the input impedance matching. A prototype of this antenna was fabricated and experimentally characterized. The measurements confirmed the Huygens source nature of the prototype antenna.

GSM Based Security Lock Using Linear Actuator

Abstract: Security describes the protection of life and property. There are doors to keep people out, key locks and chain reinforce the mode of security. Doors are being made of metals not wood anymore. Influential persons in our society have bullet proof doors to ensure a good measure of security of self and family. This has brought about the need to review the reliability of already existing systems and look into the possibility of creating better system that are smarter and more secure. The existing system largely consists of physical lock and keys. The problem with existing system is that it can cause security issues with the case of burglaries. The burglar can grapple with vault key and study it which can cause considerable damage to the property and valuable materials in the safe. Also, physically locks can be opened by lock picks. The main idea of designing the GSM based security locking system is to provide many modern security features than manual operated mechanical lock. The proposed locking system uses Microcontroller, GSM modem, switching circuit, relay and Linear Actuator.

Dual Band Monopole Antenna with Concentric Square Electromagnetic Band Gap (EBG) Structure

Abstract: In this Paper, a Dual Band Monopole Antenna has been presented for GSM 900 and Wi-Fi band. To improve the performance parameters of the antenna, concentric square shaped electromagnetic band gap (EBG) structure has been incorporated. FR4 substrate is used and the proposed antenna is fed by line feed technique. The outer cell of $6.8533^{\ast}6.8533\text{mm}^{2}$ has been designed for GSM 900 band and inner cell of $2.557^{\ast}2.557\text{mm}^{2}$ is tuned to Wi-Fi band. The structure without EBG, reported a gain of 6.1928dB and 5.72499dB for GSM 900 band and Wi-Fi band respectively. The return loss of - 16.36116dB and -14.12084dB was obtained for GSM 900 and Wi-Fi band correspondingly. Introducing a concentric square EBG cells, the gain of 6.3391dB and 7.1013dB is obtained for GSM 900 and Wi-Fi bands individually. Return loss of the antenna is also improved for both the bands which makes the proposed antenna suitable for GSM and Wi-Fi applications.

Vehicle lock control method and device thereof, vehicle lock equipment and storage medium

Abstract: The embodiment of the invention provides a vehicle lock control method and a device thereof, vehicle lock equipment and a storage medium, and the method comprises the steps: controlling a network modeof a vehicle lock to be switched from a GSM mode to an NBIOT mode when determining that first switching time is up so as to enable the vehicle lock to communicate with a server based on the NBIOT mode; and when it is determined that the second switching time is up, controlling the network mode of the vehicle lock to be switched from the NBIOT mode to the GSM mode so that the vehicle lock communicates with the server based on the GSM mode. The problems that in the prior art, power consumption is large, GSM signals are weak, and vehicles cannot be accurately monitored are solved.

Frequency Reconfigurable Multiband Planar Antenna for Multistandard Communications

Abstract: In this work, a novel frequency-reconfigurable printed antenna is proposed. The structure consists of a capacitively loaded loop (CLL) introduced into the near field region of a coplanar waveguide (CPW) printed monopole antenna. By embedding a pair of capacitors C1 and C2 between each CLL element and the ground plane, we can easily generate and control two resonant frequencies in addition to the main resonant frequency of the reference structure at 2.45GHz. The proposed antenna achieves a frequency reconfigurable band with tuning range from 0.6GHz to 1.06GHz (LTE 600, LTE 700 and GSM 900 bands) when varying the C1 capacitance values from 1 to 7pF and 1.35 to 2.03 GHz (AWS, DCS and UMTS bands) when varying the C2 capacitance values from 0.1 to 0.7pF with reasonably good gain (>1.5 dBi) and efficiency (82%). The presented antenna has a compact size of $50 \times 35$ mm2. The proposed design is validated by simulations, displaying good results of impedance mismatch, gain pattern and radiation efficiency. The reconfigurability, range tuning and compact size makes the presented antenna well suitable for the future 5G systems to achieve dynamic spectrum access and deal with the spectrum shortage problem.

Jammer device: Implementation for GSM in Iraq

Abstract: In our daily life, the cell phones produce burden in the spots where the quietness and security are significant. Just as, in specific areas the utilizing of telephones is declined because of the security reasons and in test classes. Jammers are devices cutoff the link between the cellphone/base stations by means of transmit a sign in a similar freq. Yet bigger power with no interference inside correspondences another cell at the predefined area. In this paper, jammer device for GSM 900, 1800 MHz is designed and implemented to make an impermanent dead land on GSM in Iraq so as to make mobile phone not accept or send the signs to basestation. Originally, Jammers are allocated for military to save people but recently it used civilian. Proposed system has the ability to show you whether the system is work or not via the LCD that show messages for events during the work with the Arduino.

Data sending method, data receiving method, platform server and terminal

Abstract: The invention provides a data sending method, a data receiving method, a terminal and a platform server, and the data sending method comprises the steps: sending to-be-issued downlink data to the terminal through a GSM short message, or sending indication information to the terminal through the GSM short message or GSM signaling, wherein the indication information is used for triggering the terminal to establish NB-IoT connection to receive downlink data to be issued, and the terminal supports a GSM mode and an NB-IoT mode at the same time. According to the scheme of the invention, when the NB-Iot/GSM multimode dual-standby terminal is in a downlink unreachable state, the NB-Iot/GSM multimode dual-standby terminal can still receive downlink data, thereby ensuring that the downlink data canbe reachable in time.

Realization of RF and Microwave Energy Harvesting System Adapted to GSM-900 Network for Low Power Consumption Sensors Feeding

Abstract: This paper presents a miniaturized RadioFrequency (RF) and microwave energy harvesting system adapted to GSM-900 Network (Global System for Mobile Communication). Most researchers have worked in this domain by trying to harvest an enough DC output voltage to feed different electronic devices to ensure their energy autonomy. The matter with these systems lies in the antenna size. The proposed system is realized on Teflon hybrid technology. The size of the proposed multiband antenna is of 20x30x0.67 mm, and that of the rectifier matched to the antenna is of 10x15x0.67 mm. The measurement shows that the antenna is able to cover GSM900 (935 – 960) MHz, (1470 – 1550) MHz, GSM1900 (1935 – 1989) MHz and (3 – 3.2) GHz, bands. The output Direct Current (DC) harvested voltage measured is of 0.3 V for 2 kΩ resistance load. This result is sufficient for feeding low power consumption Wireless Sensor Networks (WSNs). In this paper, the selected temperature sensor operates for 0.2 V and 23 nW power supply. The equivalent resistor of this sensor is 2 kΩ. The DC output voltage can reach 0.8 V for open load. Keywords--RF Energy harvesting; Multi-bandes antenna; Miniaturized antenna; Impedance matching; Rectifier.