GSM Applications Research Articles

Polarization-insensitive compact frequency selective surface with higher angular stability for GSM applications

This article proposes a highly compact, angularly stable, and polarization-insensitive frequency selective surface (FSS) based bandstop filter geometry for shielding electromagnetic (EM) radiations across the GSM band. Each of the unit cells (having dimensions of 10 mm × 10 mm) is made of convoluted meander patterns, which are orthogonally printed on both sides of a dielectric substrate to design this highly compact FSS (the unit cell size is 0.029λ0· 0.029λ0, where λ0 corresponds to the resonance frequency). The metallic pattern on the top layer of the substrate selectively reflects the EM wave for one particular polarization around 890 MHz but transmits the orthogonally polarized wave. In contrast, the pattern printed on the bottom layer behaves oppositely (allowing one polarization and reflecting other polarization), thereby the overall structure exhibiting a bandstop filter response with a 3-dB stop bandwidth ranging from 800 MHz to 960 MHz under dual polarizations. In addition, the geometry exhibits a high angularly stable response till 80° angle of incidence under both transverse electric (TE) mode and transverse magnetic (TM) mode. Good agreement is also observed between the simulated and measured responses for various cases.

Optically transparent coplanar wideband antenna for vehicular communication

SummaryThe presented state of the art is a novel coplanar optically transparent antenna designed to operate in extended GSM, L‐band, and UWB applications for vehicular communication. The presented radiator operates using a coplanar waveguide feed mechanism without a separate ground plane layer with a minimal conductive surface to enhance the transparency of the proposed antenna. The proposed antenna design has dimensions of 40 × 20 mm2, and a transparent material of soda–lime glass is used as a substrate with a dielectric constant of 7. The radiating element over the substrate is the conductive film fluorine‐doped tin oxide (FTO) with a sheet resistance of 7 Ω/sq. The operating frequency range of the designed antenna is from 0.86 to 14.45 GHz, which encloses the E‐GSM (900 MHz), L‐band (1–2 GHz), and UWB (3.1–10.6 GHz) frequencies. The peak gains at the operating frequencies are 1, 1.6, and 4.34 dBi, respectively. The designed antenna is fabricated and measured, and the performance metrics are plotted and compared. Since the transparent antenna is designed, the tendency of a substance to conduct light is measured as the optical transmittance, and it is calculated as 95% in the glass reference and 82% in the air reference.

Novel energy harvesting microstrip Lowpass-Bandpass diplexer with an Ultra-Compact size for GSM and 5G communication systems

A new microstrip layout is proposed to design an ultra-compact lowpass-bandpass diplexer. This structure includes a basic bandpass resonator (BPR) in which, a lowpass filter (LPF) is embedded. Accordingly, it occupies an area of 0.008 λg2 that is the smallest compared to earlier reported lowpass-bandpass diplexers mentioned in this work. Moreover, at the lower and upper passbands, it has low insertion losses of 0.006 dB and 0.1 dB respectively. Meanwhile, the return loss at both channels reaches 30 dB. Having low losses makes it suitable for energy harvesting applications. The cut-off frequency of its lowpass channel is located at 0.93 GHz, while the bandpass section resonates at 2.05 GHz. Therefore, it can be used for GSM and 5G applications. Another advantage of this diplexer is its suppressed harmonics from the 1st to the 4th. To design this diplexer, a comprehensive mathematical analysis is performed on the basic structure. Our designed diplexer is fabricated and measured. The simulated scattering parameters and extracted data through direct testing are close to each other with good accuracy.

Penerapan Graphic Standard Manual pada Visual Identity Produk Komoditi Batik Berpotensi Ekspor

Mahkota Laweyan is a Small and Medium Industry in the field of environmentally friendly batik and produces "Toeli" brand batik made by deaf people. Recruitment of deaf people is intended to provide equal opportunities and rights for disabled people to get decent work. Mahkota Laweyan employs 17 employees and now has 17 types of patented batik products. These batik commodity products have met Indonesian National Standards (SNI) and have export potential. This product also has the right to use the collective brand held by the Laweyan Batik Kampoeng Development Forum (FPKBL). However, each batik product that has a patent requires a visual identity. For export purposes, a strong visual identity is needed because it is very important for products that have a good reputation. So far, visual identity design still does not use the GSM correctly so that it often experiences problems in visual identity consistency. The main problem faced by Mahkota Laweyan is a lack of understanding about GSM which is a basic requirement for marketing activities. Batik commodity products with export potential that have been produced and meet SNI do not yet have the visual identity they should have. Thus, the aim of implementing this activity is to help in solving problems in the application of GSM to visual identity. This assistance in the context of implementing community service is aimed at assisting SME Mahkota Laweyan with aspects of visual communication needs for marketing and branding purposes. The mentoring methods used in this service activity are lectures, demonstrations, and training methods for developing visual identity by applying GSM appropriately on batik products with export potential. The result of this activity was the creation of GSM and its application to various visual communication media accompanied by educational institutions from Malang State University.

A Wilkinson power divider with harmonic suppression through low-pass filter for GSM and LTE applications

Conventional Wilkinson power dividers (WPDs) perform satisfactorily near the intended operation frequency. Nonetheless, these WPDs demonstrate subpar performance in the stopband and necessitate a significant physical space. To enhance the existing level of advancement and in order to improve on the current state-of-the-art, a modified WPD is designed and fabricated, demonstrating a significant improvement in stopband and superior isolation between output ports. To improve the stopband and suppress unwanted harmonics, a low-pass filter (LPF) structure is placed in the both branches of the conventional WPD. The proposed modified WPD depicts a wide stopband bandwidth (fSB > 17.25 GHz) from 2.75 to over 20 GHz with an attenuation level of 20 dB, suppressing 2nd to 11th harmonics. According to measured results, the input return loss (|S11|), insertion loss (|S21|) and output isolation (|S32|) at f = 1.8 GHz are better than 33 dB, 3.2 dB and 21 dB, respectively. Indeed, the proposed modified WPD exhibits a magnitude imbalance of 0.00018, a phase imbalance of 1.25 degrees and a group delay of 0.5 ns. The proposed WPD depicts a compact size of 35 mm × 25 mm (0.38 λg × 0.27 λg), where λg is the guided wavelength at f = 1.8 GHz. There is a good agreement between the simulated and measured results. According to the obtained results, the proposed modified WPD shows a desirable performance for modern LTE and GSM communication applications.

Ring Shape Microstrip Antenna Backed by Modified Ground Plane for Multiband Response in GSM and Radar Applications

Ring Shape Microstrip Antenna Backed by Modified Ground Plane for Multiband Response in GSM and Radar Applications

An ultra-compact diplexer based on simple microstrip coupled lines for GSM and wideband wireless applications

An ultra-compact diplexer based on simple microstrip coupled lines for GSM and wideband wireless applications

Optimizing dual-band antenna efficiency: Ridge width parametric study of quad ridge horn antennas

The purpose of this project was to develop a quad ridged horn antenna for a GSM and mid band 5G application, capable of dual frequency range operation at 1.8 GHz and 3.5 GHz. The antenna was constructed using 3D printing technology and Polylactic Acid (PLA), a thermoplastic polymer known for its high strength and compatibility with 3D printing processes. The impact of varying ridge width dimensions on the antenna's performance was evaluated using a range of parametric techniques. Ridge widths of 10 mm, 13.5 mm, and 17 mm were analysed to assess the effects of dimension alterations. Results demonstrated that the antenna is capable of dual band frequency operation with signal reflections of -16.89 dB and -28.60 dB at 1.8 GHz and 3.5 GHz, respectively. This research contributes to the development of efficient and cost-effective antennas for wireless communication applications in the GSM and mid band 5G spectrum.

DESIGN OPTIMIZATION OF LOW NOISE AMPLIFIER FOR 900MHZ GSM BAND APPLICATIONS USING GREY WOLF ALGORITHM

In this work, the design of a high-performance single-stage Low Noise Amplifier (LNA) for GSM applications is taken into consideration. LNA design is one of the key stages of a wireless communication system due to its dominance over the whole system's noise figure performance. Although it is possible to achieve a very high gain and low noise figure with the usage of multi-stage transistors, such designs would also have a high complexity and manufacturing cost. The main aim of this work is to propose a single transistor LNA design for GSM application with a gain level of 14.3 dB, return loss level of less than 15 dB, and noise figure of 1.8 dB over the operation band of 820-980 MHz. the optimal design variables of the model is obtained via Grey Wolf optimization procedure.

Microstrip lowpass-bandpass triplexer with flat channels and low insertion losses: Design and fabrication for multi-service wireless communication systems

In this work, a new basic microstrip structure is proposed and analyzed to obtain a lowpass-bandpass triplexer without any extra matching networks. This is despite the fact that the number of literature on lowpass-bandpass triplexers that have been introduced so far is very low. The lowpass channel cut-off frequency is tuned at 1.85 GHz which makes it appropriate for mid-band 5G and GSM applications. The bandpass channels work at 3.25 GHz and 6.65 GHz for S-band, 5G, WiMAX and C-band applications. The designed triplexer occupies a compact area of 0.021 λg2. In comparison with the previously reported triplexers, the presented triplexer has three low insertion losses of 0.54 dB, 0.16 dB and 0.55 dB. Also, all its channels are flat with three low group delays of 0.79 ns, 0.98 ns and 0.85 ns. For verifying the designing technique and simulation results, we fabricated and measured our triplexer, where all the obtained results are close to each other.

A Compact Rat-Race Coupler with Harmonic Suppression for GSM Applications: Design and Implementation Using Artificial Neural Network.

In this paper, a compact microstrip rat-race coupler at a 950 MHz operating frequency is designed, simulated, and fabricated. New branches are proposed in this design using high-/low- impedance open-ended resonators. In the conventional rat-race coupler, there are three long λ/4 branches and a 3λ/4 branch, and they occupy a very large area. In the presented designed, three compact branches are proposed for use instead of three λ/4 branches and an ultra-compact branch is suggested for use instead of the 3λ/4 branch. Additionally, an artificial neural network (ANN) approach is incorporated to improve the performance of the resonators using a radial basis function (RBF) network. The proposed compact structure has achieved a reduction of more than 82% compared with the size of the conventional coupler structures. Additionally, the proposed coupler can suppress the 2nd up to the 5th harmonic to improve the performance of the device.

Dual-Band and Wideband Bandpass Filters Using Coupled Lines and Tri-Stepped Impedance Stubs.

In this paper, two bandpass filters-one with a dual-band response and the other with a wideband response-were designed, implemented, and experimented with. The filters are based on the novel combination of series coupled lines and tri-stepped impedance stubs. However, coupled lines along with tri-stepped impedance open stubs (TSIOSs) give a third-order dual passband response. The advantage of dual-band filters using coupled lines and TSIOSs is that they have wide passbands that are close together and separated by a single transmission zero. In contrast, the inclusion of tri-stepped impedance short-circuited stubs (TSISSs) instead of TSIOSs provides a fifth-order wide passband response. The advantage of wideband bandpass filters using coupled lines and TSISSs is that they have a very good selectivity factor. Theoretical analysis was carried out to validate both filter configurations. The tested bandpass filter using coupled lines and TSIOS units had two close wide passbands operating at 0.92 and 1.52 GHz center frequencies, respectively. The dual-band bandpass filter was implemented to operate in GSM and GPS applications. The first passband had a 3 dB fractional bandwidth (FBW) of 38.04%, while the second passband had a 3 dB FBW of 22.36%. The experimental result of the wideband bandpass filter (with coupled lines and TSISS units) had a center frequency of 1.51 GHz with a 3 dB fractional bandwidth of 62.91% and a selectivity factor of 0.90. A good congruence was demonstrated between the full-wave simulated and tested results for both filters.

Ultracompact SIRC-Based Self-Triplexing Antenna with High Isolation

An ultracompact self-triplexing antenna realized on a substrate-integrated rectangular cavity (SIRC) is discussed in this study. The proposed structure employs two L-shaped slots and an inverted U-shaped slot to radiate at three independent operating frequency bands. Three 50-ohm microstrip feed lines were used to excite the radiation in these slots. The operating frequency was individually tuned using the slot size. The slot placement and size were designed having in mind considering obtaining one or more frequency bands below the SIRC cutoff frequency, which had the advantage of enabling an ultracompact size. High port isolation was achieved by applying one of the ports orthogonally to the two remaining ones, which created a weak cross-coupling channel. A lumped-circuit model was created to examine the antenna operation. The presented design has been prototyped and experimentally validated with the measured operating frequencies of 1.92 GHz, 4.43 GHz, and 5.25 GHz for GSM, 5G, and WLAN applications, respectively. The port isolations are better than 32.4 dB according to both EM simulations and measurements. Meanwhile, the measured realized gain of the antenna is better than 4.3 dBi at all bands.

Modern 5G MIMO Antenna for Vehicular Communication and Safety

A Modern 5G Multiple Input Multiple Output (MIMO) antenna alignment with frequency range for the 5G NR-n2 band (1.81 GHz) and protection band (5.85 GHz) that are dual-band for automobile communication and safety is offered. In a relatively shrunken dimension in relation to its working wavelength, the smallest frequency of resonance is relatively challenging to attain. The antenna's dimensions are 60 mm × 60 mm × 1.6 mm and it achieves a gain of 4.65 dBi and 3.38 dBi, at the frequency range of 1.81 GHz and 5.85 GHz. Because of the presence of ground slot, MIMO antennas offer isolation values of more than 19 dB and diversity gains that are comparatively close to 10 dB. In GSM and safety applications, this enhanced square single-element and MIMO antenna offers a noticeably increased gain and improved performance. The on-vehicle study of MIMO setups is performed to ensure the durability of the specified antenna in an automotive application.

Design and fabrication of a Wilkinson power divider with harmonic suppression for LTE and GSM applications

Conventional Wilkinson power dividers (WPDs) can provide acceptable performance close to the nominal center frequency. However, these WPDs can also exhibit poor out-of-band performance while requiring a large footprint. In order to improve on the current state of the art, a modified microstrip WPD is proposed that exhibits a substantially improved stopband and high isolation. A lowpass filter (LPF) structure is utilized in both branches of the power divider to provide harmonic suppression. According to the obtained results, the input return loss (|S11|), output return loss (|S22|), output insertion loss (|S21|) and isolation (|S32|) are better than 34.2 dB, 26.2 dB, 3.52 dB and 31.2 dB, respectively. The proposed modified WPD has a wide 20 dB stopband (from 2.54 GHz to 13.48 GHz) and filters the second to seventh harmonics with attenuation levels of greater than 20 dB. The proposed WPD has a small size of 33.8 mm × 27 mm (0.42 λg × 0.33 λg), where λg is the guided wavelength at the operating frequency of 1.8 GHz. The WPD has been fabricated and tested and shows good agreement between simulated and measured results and the proposed design has desirable characteristics for LTE and GSM applications.

Design and fabrication of a compact branch-line hybrid coupler with a balanced phase using a new microstrip structure for GSM applications

A novel microstrip quadrature hybrid coupler is mathematically designed, optimized and fabricated in this work. The physical structure of the proposed coupler is new and it occupies a very small area of 0.01 λg2. The novel stubs embedded inside the conventional rectangle are connected parallel lines. The ends of these stubs are connected to a solid rectangle, which make the overall structure different from the previous works. Our branch-line coupler is designed to work at 1.8 GHz for GSM applications. The phase imbalance between S21 and S31 is only 0.01°, which is very small compared to the previous works. Another advantage of the presented coupler is its high isolation, which is about 40 dB. Meanwhile, other parameters such as common port return loss and coupling factors are desired. To design this coupler, two low-loss lowpass filters (LPFs) are designed and embedded in the main structure. A mathematical design method is presented to decrease the losses, where a 0.002 dB insertion loss for the LPF is achieved. We measured the presented structure. The measurement results verifies the simulations with high accuracy. Therefore, due to having a novel structure, very small size, the lowest phase shift, good isolation and good return loss the proposed coupler can be easily used in RF communication systems.

Dual Band MIMO Antenna with High Isolation for GSM and WLAN Applications

Dual Band MIMO Antenna with High Isolation for GSM and WLAN Applications

Macro Model for Discrete-Time Sigma‒Delta Modulators

This work presents a macro model for discrete-time sigma‒delta modulators, which can significantly reduce the simulation time compared to transistor level circuits. The proposed macro model is realized by effectively combining active and passive ideal circuit components with Verilog-A modules. As such, since the macro model is a true representation of the actual transistor level circuit, a moderately good accuracy can be obtained. In addition, the proposed macro model includes the major amplifier, comparator, and switch‒capacitor non-idealities of the sigma‒delta modulator such as amplifier DC gain, GBW, slewrate, comparator bandwidth, hysteresis, parasitic capacitance, and switch-on resistance. The results show the simulation time of the proposed macro model sigma‒delta modulator is only 6.43% of the transistor level circuit with comparable accuracy. As a result, the proposed macro model can facilitate the circuit design and leverage non-ideality analysis of discrete-time sigma‒delta modulators. As a practical design example, a second order discrete-time sigma‒delta modulator with a five-level quantizer is realized using the propose macro model for GSM and WCDMA applications.

A Novel Low-Profile 5G MIMO Antenna for Vehicular Communication

The proposed work is a novel low-profile 5G MIMO antenna configuration to exhibit dual-band frequencies for 5G NR-n2 band (1.9 GHz) and safety band (ITS-5.9 GHz) in vehicular communication. In the proposed antenna, it is quite difficult to achieve the lowest resonance frequency in a comparatively miniaturized dimension concerning its operating wavelength. The designed antenna is a modified square patch with the dual-band resonance achieved by the incorporation of slots for increasing the electrical length within the dimension. Hence, the design comprises ring and loop slots exhibiting resonance at 1.9 GHz and the loop U, and modified-W slots for 5.9 GHz. The antenna achieves 1.9% and 0.64% impedance bandwidth and a peak gain of 1.944dBi and 6.06dBi at the resonant frequencies of 1.9 GHz and 5.9 GHz, respectively, with dimensions of 0.114λo × 0.114λo × 0.0016λo, where λo is the wavelength of the lowest operating frequency. The MIMO configuration is presented to assess the antenna’s suitability for large-scale applications. The MIMO antenna presented here is deployed with the edge-to-edge distance between the single element radiators being 0.01λo by parametric sweep. The presented MIMO antenna provides an isolation value greater than 19 dB because of reduced mutual coupling between the single element radiators in that MIMO structure due to the presence of a ground slot. The ECC values are 1.659 × 10−9 and 0.000601 for frequencies of 1.9 GHz and 5.9 GHz, respectively, and the diversity gain is relatively near 10 dB, which is the acceptable value for MIMO antennas. This modified square single-element and MIMO antenna provides a relatively higher gain and better performance in vehicular communication for GSM and safety applications. The MIMO configurations’ on-vehicle analysis is performed to check the reliability of the designed antenna in a vehicular environment.

PENGEMBANGAN APLIKASI (GSM) BERBASIS ANDROID DALAM PEMAHAMAN MASASE OLAHRAGA DAN PENCEGAHAN CEDERA BAGI GURU PJOK

Knowledge related to the process of providing first aid and early injury prevention during PJOK learning activities (sports) is an important thing that needs to be known. Therefore, this study aims to analyze the GSM application model and analyze the feasibility of an Android-based GSM application in understanding sports massage and injury prevention for PJOK teachers. Data collection techniques in this study used product validation sheets and questionnaires. The data analysis technique in this study used qualitative data analyzed by descriptive statistics. The subjects of this study were PJOK teachers throughout Surabaya who were divided into small groups of 15 people and large groups of 35 people. The results of the small group trial include 3 aspects of the assessment in the form of aspects of appearance, aspects of content/material, aspects of usefulness. The display aspect with a total score of 20 is in the “Good Enough” category, the content/material aspect with a total score of 38.6 is in the “Good enough” category, and the usefulness aspect with a total score of 15.3 is in the “Good” category. The results of the large group trial of the display aspect with a total score of 24 including the "Good" category, the content/material aspect with a total score of 49.8 including the "Good" category, and the usefulness aspect getting a score of 17 including the "Very Good" category. The conclusion in this study is that an Android-based application (GSM) in understanding sports massage and injury prevention is appropriate for PJOK teachers.