GPS Patch Antennas Research Articles

Innovative Systems Engineering Solutions for Power-Positive Operations: Navigating the Multi-Constraint Challenges of the SWARM-EX CubeSat Mission

Although the small stature of CubeSats and their standardized deployer options help to lower unit development cost and facilitate launch opportunities, the physical size limits of CubeSats prove to be a double-edged sword vis-à-vis sustaining a stable power state while hosting instruments with high power demands and often strict pointing requirements. For the Space Weather Atmospheric Reconfigurable Multiscale-EXperiment (SWARM-EX), this issue is magnified by the mission’s ambitious goals; to comply with mission requirements, a SWARM-EX spacecraft is required to concurrently (1) point the science instruments no more than 30° off ram when they are operational, (2) point the GPS patch antenna no more than 30° off zenith at least once per orbit, (3) point the boresight of the X-Band patch antenna no more than 18° from the ground station during downlink, (4) maximize the differential cross-sectional area during differential drag maneuvers, and (5) maximize solar array power generation at all times. Consequently, leading-edge CubeSat missions like SWARM-EX require innovative systems engineering solutions to remain power-positive during on-orbit operations. Through the design of a comprehensive module-based concept of operations, orbital power generation simulations, intricate constrained attitude profiles, and a configurable battery state of charge simulation tool, the SWARM-EX mission designers have conceived a plan to retire the risk of not maintaining a power-positive state while successfully meeting all mission requirements; it is the aim of the authors to illuminate these strategies as a case study.

Investigate Bending Effect of Wearable GPS Patch Antenna with Denim and Polyester Fabric Substrate

Investigate Bending Effect of Wearable GPS Patch Antenna with Denim and Polyester Fabric Substrate

IMAGING OF MICROWAVE NEAR-FIELD DISTRIBUTION OF GPS PATCH ANTENNA

Microwave near-field distribution of the GPS patch antenna was visualized by a thermo-elastic optical indicator microscopy (TEOIM) technique at $1.575~GHz$. Visualization of the antenna radiation is realized to describe the electromagnetic field intensity and distribution depending on the distance from the antenna surface and optical indicator. Experimental data was compared and confirmed with simulation results, which are in good agreement. Possible applications of the TEOIM system were discussed.

Ultra-Low Loss Mg2TiO4 Based Dielectric Ceramics for Microwave Applications: An Overview

For several decades, temperature stable, medium permittivity, and low loss dielectric ceramics have been used as resonators, oscillators, filters, and GPS patch antennas for microwave communication systems. Various microwave dielectric ceramics have been proposed and widely used in telecommunication industries. Among the most interesting materials of that kind, magnesium orthotitanate (Mg<sub>2</sub>TiO<sub>4</sub>) is recognized as one of the most promising low loss microwave materials, which played an important role in the field of microwave and millimeter wireless communication industry. It was found that by modifying the Mg<sub>2</sub>TiO<sub>4</sub> compound with other materials, their microwave dielectric properties have changed tremendously. The main purpose of this review is to gather information about Mg<sub>2</sub>TiO<sub>4</sub> - based low loss dielectrics used for microwave applications. The study also helps the researchers and technologists to get compact information for Mg<sub>2</sub>TiO<sub>4</sub> -based compounds all over the world.

Numerical evaluation of external magnetic effect on electromagnetic wave transmission through reentry plasma layer

Numerical study of electromagnetic (EM) wave transmission through the magnetized plasma layer is presented in this paper. The plasma parameters are derived from computational fluid dynamics simulation of the flow field around a blunt body flying at supersonic speed and serve as the background plasma condition in the numerical modeling for EM wave transmission. The EM wave is generated by our newly designed coaxial feed GPS patch antenna. The external magnetic field is applied and assumed to vary linearly as a function of wall distance. The effects of the external applied magnetic field and the plasma parameters on wave transmission are studied, and the results show that EM wave propagation in the non-uniformly magnetized plasma is a matter of impedance matching, and the EM wave transmission can be adjusted only when the proper strength of the magnetic field is applied.

Fabrication and Characterization of TiO<sub>2</sub>-Doped ZnAl<sub>2</sub>O<sub>4</sub> Nanocrystals via Sol-Gel Method for GPS Antenna

The Zn(1-x)TixAl2O4 (x = 0.00, 0.05, 0.15 & 0.25) nanocrystals thin films were prepared by sol-gel method. The properties of Zn(1-x)TixAl2O4 were investigated by X-ray diffraction (XRD), Atomic Force Microscope (AFM), Fourier transform infrared spectra (FTIR) and (UV-Vis). By indexing the XRD patterns, we identified three structural types which is ZnAl2O4, anatase and rutile. The addition of TiO2 increased the crystallite size from 14.65 to 25.25 nm. The direct band gap was found to be around 3.35 to 3.84 eV. The addition of TiO2 increased the crystallite size, surface roughness, and lattice parameters of the resultant films, evidently affecting their density and dielectric constant (). The thin films were characterized in the certain frequency to determine the using LCR spectrometer. The and density value of the Zn(1-x)TixAl2O4 films increase linearly from 8.56 to 13.48 and 4.60 to 4.70 g/cm3 with the increasing of x value, respectively. Based on the material analysis and microwave antenna theory, GPS patch antennas were fabricated using the Zn(1-x)TixAl2O4 material. The fabricated GPS antenna with the highest (13.48) material exhibits the smallest size of antenna which is 7.45 cm2. The performances and the operating frequencies were measured using a PNA series network analyzer. The result showed that all patch antennas operate at frequency of 1.570 GHz. The GPS patch antenna fabricated from Zn0.25Ti0.75Al2O4 showed an excellent combination of return loss (-29.6 dB), smallest size (7.85 cm2), and wide bandwidth (195 MHz). All fabricated antennas are meets the requirements of GPS applications.

A Review onDesign of a high gain MicrostripAntenna using Parasitic Patch for GPSApplication

GPS patch antennas are gaining their importance nowadays due to their importance in the communication engineering. This paper proposes a novel approach to increase the gain of microstripantenna.The application of gap-coupled mechanism for achieving high gain with microstrip antenna has been proposed .This present work includes the designing of patch antenna for the applications of Global positioning systems antenna in the handheld equipment. The antenna will operate at the desired frequency of 1.57GHz with 80 MHz bandwidth. An FR4 substrate of dielectric constant 4.4 and dielectric loss tangent of 0.027 is used in this present work. The proposed antenna possesses an average gain of 4.0 dB overall the GPS L1 operation. Return loss, input impedance smith chart, 3D gain, radiation patterns and field distributions are simulated and presented in this paper by using commercial Ansoft-HFSS software.

Synthesis and fabrication of GPS patch antennas by using Zn(1 − x)Ti x Al2O4 thin films

Zn(1 − x)Ti x Al2O4-based microwave dielectric ceramics were prepared by sol–gel method. The obtained compounds were characterized and fabricated as GPS patch antennas. The XRD patterns show a three-phase system with a spinel ZnAl2O4, anatase and a rutile (TiO2). The addition of TiO2 increased the crystallite size and grain size, and surface morphology tended to increase the ceramics density (4.61–4.75 g/cm3) and dielectric constant, e r (8.56–13.51). Based on the material investigated and microwave antenna theory, GPS patch antennas were fabricated using Zn(1 − x)Ti x Al2O4 and then measured using a PNA series network analyzer. The surface of the GPS patch antennas and ground plane was coated with 200-nm-thick silver to enhance ohmic contact. The patch antenna sizes decreased as e r increased from 2.88 × 4.37 cm (12.58 cm2) to 3.53 × 2.21 cm (7.80 cm2). Among these antennas, the Zn0.70Ti0.30Al2O4 shows an excellent performance combination between return loss (−28.71 dB), small size (3.53 × 2.21 cm), and wide bandwidth (270 MHz).

Characterization of TixZn(1-x)Al2O4 thin films by sol-gel method for GPS patch antennae

The need for miniaturization and weight reduction of a GPS patch antennae has forced scientists to search for new microwave dielectric materials. The sol-gel method was used to prepare TixZn(1-x)Al2O4-based microwave dielectric ceramic thin films (x = 0.00, 0.10, 0.20 and 0.30) and to fabricate a GPS patch antennae. The phases of ZnAl2O4 and TiO2 co-exist with each other and form a two-phase system, which is confirmed by the X-ray diffraction (XRD) patterns and the Fourier-transform infrared (FTIR) spectra analysis. The addition of titanium dioxide (TiO2) increased the crystallite size, grain size, surface roughness and apparent density. A material with a higher density tends to increase the dielectric constant (er), which is suitable for miniaturization of a GPS patch antenna. As the TiO2 content increased, the er values increased linearly. Finally, GPS patch antennae were successfully fabricated using the ZnAl2O4 and Ti0.30Zn0.70Al2O4 material. The performances and the operating frequencies of the GPS patch antennae were measured using a PNA series network analyzer. The result showed that both patch antennae resonated at frequency of 1.570 GHz and gave a return loss less than -10 dB. The optimal performance of the GPS patch antennae was obtained from the specimen using Ti0.30Zn0.70Al2O4 (er ~ 14.57, wide bandwidth of 240 MHz and low return loss of -34.5 dB), which meets the requirements of GPS applications.

Effect of B<sub>2</sub>O<sub>3</sub> Glass on the Sintering and Microwave Dielectric Properties of MgTiO<sub>3</sub>–CaTiO<sub>3</sub>

The effects of B2O3additive on the microstructures, the phase formation and the microwave dielectric properties of MgTiO3–CaTiO3ceramics were investigated. The sintering temperature of B2O3-doped 0.95MgTiO3–0.05CaTiO3ceramics can be lowered to due to the liquid phase effect. Formation of second phase MgTi2O5can be effectively restrained through the addition of B2O3. The microwave dielectric properties are found strongly correlated with the sintering temperature as well as the amount of B2O3addition. At , 0.95MgTiO3–0.05CaTiO3ceramics with 10 wt% B2O3addition possesses a dielectric constant of 18.3, aQ×fvalue of 20,000 (at 7 GHz) and a value of −6.12 ppm/. In comparison with pure 0.95MgTiO3–0.05CaTiO3ceramics, the doped sample shows not only a 22% loss reduction but also a lower sintering temperature. That makes it a very promising material to replace the present one for GPS patch antennas.

Dielectric Properties and Applications of Low‐Loss (1−x)(Mg0.95Ni0.05)2TiO4‐xSrTiO3 Ceramic System at Microwave Frequency

The microwave dielectric properties of conventional solid‐state route prepared (1−x)(Mg0.95Ni0.05)2TiO4–xSrTiO3 ceramic system have been investigated. A two‐phase system was confirmed by the X‐ray diffraction patterns. (Mg0.95Ni0.05)TiO3 was also detected as a second phase in the system. The microwave dielectric properties are strongly related to the density and the morphology of the specimens. The presence of the second phase, however, would cause no significant variation in the dielectric properties of the specimen because it possesses similar properties compared with that of the main phase (Mg0.95Ni0.05)2TiO4. Specimen using 0.93(Mg0.95Ni0.05)2TiO4–0.07SrTiO3 leads to a good combination of microwave dielectric properties with an εr of 24.88, a Q×f of 98,400 (at 9.8 GHz) and a τf value of 1.43 ppm/°C. It is proposed as a candidate dielectric for applications in GPS patch antennas, 3G and 4G passive components. Moreover, an open stub band‐pass filter with central frequency of 2.4 GHz was also designed and fabricated employing the proposed dielectric to study its performance. It also showed a substantial reduction in both insertion loss and size in comparison with other dielectrics FR4 and alumina.

Effect of Zn Site for Ca Substitution on Optical and Microwave Dielectric Properties of ZnAl2O4Thin Films by Sol Gel Method

CaxZn(1-x)Al2O4(x= 0.00, 0.05, 0.10, 0.15, 0.20, 0.25, and 0.30) thin films were prepared by a sol gel method. The XRD patterns displayed the characteristic peaks of (Ca/Zn)Al2O4with the standard pattern of face-centred cubic (fcc). The addition of Ca decreased the lattice constant from 14.6 nm to 23.2 nm. The optical bandgap of undoped thin film was found to be at 3.84 eV while for doped Ca was observed at 3.50 to 3.73 eV. The substitution of Zn2+by Ca2+in ZnAl2O4thin films was found to increase the crystallite size, grain size, and surface morphology which evidently affect the density and dielectric constant. TheCaxZn1-xAl2O4thin films were characterized at 20 to 1 MHZ frequency to determine the dielectric constantεrand unloaded quality factorQuusing LCR spectrometer. It can be observed that specimen using Ca0.25Zn0.75Al2O4possessesεr~10.41andQu~5770which is suggested as a candidate material for millimetre-wave applications. Therefore, this ceramic is suggested as a candidate material for GPS patch antennas.

GPS 방해신호 회피용 5-패치 배열 안테나 설계

In this paper, the implementation of a null-steering antenna array using GPS patch antennas is suggested. The antenna array consists of five patch antenna elements fabricated on the ceramic substrate. The antenna element proposed here is a typical circular polarization patch and a prototype patch array antenna is manufactured on the PCB. The antenna has one reference element located at the center and other four elements are placed at the corners. A null in the direction of the jamming signal can be produced by changing the phases of 4-elements. Simulation results of the array antenna by CST MWS are presented and discussed. The basic performances are measured and the results are shown. The results show that the antenna presented here can be used to remove the signals from the directions of any jammers.

Miniaturization of GPS patch antennas based on novel dielectric ceramics Zn(1−x)MgxAl2O4 by sol–gel method

The need for miniaturization and weight reduction of GPS patch antennas has prompted the search for new microwave dielectric materials. In this study, a sol–gel method was used to prepare Zn(1−x)MgxAl2O4 thin films and fabricate GPS patch antennas at a low annealing temperature (700 °C). X-ray diffraction (XRD) patterns, field emission scanning electron microscopy images, Fourier transform infrared spectra, and optical band gap analyses confirmed the nanostructure of (Mg/Zn)Al2O4. The XRD patterns displayed the characteristic peaks of (Mg/Zn)Al2O4 with a face-centered cubic structure. Mg addition decreased the crystallite size, surface morphology, and lattice parameters of the resultant films, evidently affecting their density and dielectric constant (ɛ r ). Based on the material investigated and microwave antenna theory, GPS patch antennas were fabricated using Zn(1−x)MgxAl2O4 and then studied using a PNA series network analyzer. The fabricated patch antennas with different ɛ r ceramics decreased in size from 12.5 to 10.8 cm2. The patch antennas resonated at a frequency of 1.570 GHz and provided a return loss bandwidth between −16.6 and −20.0 dB; their bandwidth also improved from 90 to 255 MHz. The GPS patch antenna fabricated from Zn0.70Mg0.30Al2O4 showed an excellent combination of return loss (−20.0 dB), small size (10.8 cm2), and wide bandwidth (255 MHz). Therefore, addition of Mg improves antenna performance and decreases the dimensions of the device.

Characterization and Dielectric Properties of Novel Dielectric Ceramics CaxZn(1−x)Al2O4 for GPS Patch Antennas

A solgel method was used to prepare CaxZn(1−x)Al2O4 thin films and fabricate GPS patch antennas. The addition of calcium (Ca) has increased the εr, crystallite size, and grain size, to increase the ceramics density. The three highest Q × f values appear at the position of x = 0.05 (31,091 MHz), 0.15 (63,906 MHz), and 0.25 (40,609 MHz), respectively. The best combination of microwave dielectric properties (εr ~ 9.02), Q × f ~ 63,906 MHz and with the lowest return lost (−25 dB) is obtained for specimen using Ca0.15Zn0.85Al2O4 (x = 0.15) ceramics, which is the suggested material for GPS patch antennas.

Conformal Patch Antenna Arrays Design for Onboard Ship Deployment Using Genetic Algorithms

Conformal antennas and antenna arrays (arrays) have become necessary for vehicular communications where a high degree of aerodynamic drag reduction is needed, like in avionics and ships. However, the necessity to conform to a predefined shape (e.g., of an aircraft’s nose) directly affects antenna performance since it imposes strict constraints to the antenna array’s shape, element spacing, relative signal phase, and so forth. Thereupon, it is necessary to investigate counterintuitive and arbitrary antenna shapes in order to compensate for these constraints. Since there does not exist any available theoretical frame for designing and developing arbitrary-shape antennas in a straightforward manner, we have developed a platform combining a genetic algorithm-based design, optimization suite, and an electromagnetic simulator for designing patch antennas with a shape that is not a priori known (the genetic algorithm optimizes the shape of the patch antenna). The proposed platform is further enhanced by the ability to design and optimize antenna arrays and is intended to be used for the design of a series of antennas including conformal antennas for shipping applications. The flexibility and performance of the proposed platform are demonstrated herein via the design of a high-performance GPS patch antenna.

Ferrite loaded UHF sleeve monopole integrated with a GPS patch antenna for a handset

AbstractThis article describes the design of a compact ferrite loaded UHF sleeve monopole antenna covering 225–450 MHz that is colocated with GPS annular ring microstrip antennas on top of a handset. This antenna provides both communications and navigational capabilities to the user and is intended for military and commercial applications. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2513–2516, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27102

Phase Relation and Microwave Dielectric Properties of (Zn1−xCox)Ta2O6System

High‐dielectric constant and low‐loss ceramics in the (Zn1−xCox)Ta2O6ceramics have been prepared by the conventional mixed oxide route and their microwave dielectric properties have been investigated. A phase change or crossover from ZnTa2O6to CoTa2O6occurred atx=0.07 and was completed atx=0.11 and it tends to form a continuous solid solution elsewhere. An over‐sintered specimen would lead to a slight decrease in the density resulting in a decline of the dielectric constant and theQ×fvalue. The specimen withx=0.05 possessed an excellent combination of microwave dielectric properties: ɛr∼38.47,Q×f∼112 000 GHz, and τf∼11.2 ppm/°C. It is proposed as a candidate material for today's 3G passive components and especially small‐sized GPS patch antennas.

High-dielectric-constant and low-loss microwave dielectric in the Ca(Mg1/3Ta2/3)O3–(Ca0.8Sr0.2)TiO3 solid solution system

The crystal structures, phase compositions and the microwave dielectric properties of the (1 − x)Ca(Mg1/3Ta2/3)O3–x(Ca0.8Sr0.2)TiO3 perovskite-based composites have been investigated. The (1 − x)Ca(Mg1/3Ta2/3)O3–x(Ca0.8Sr0.2)TiO3 solid solutions exhibited an 1:2 ordered monoclinic structure for all compositions. As (Ca0.8Sr0.2)TiO3 content increases, the ɛr and τf values increase gradually, while the Q × f values decreases. By appropriately adjusting the x value in the (1 − x)Ca(Mg1/3Ta2/3)O3–x(Ca0.8Sr0.2)TiO3 ceramic system, a near-zero τf value can be achieved. The optimal microwave dielectric properties with a dielectric constant (ɛr) value of 43.37, a Q × f value of 46,000 GHz (where f = 6.8 GHz, is the resonant frequency), and a temperature coefficient of resonant frequency (τf) of −2.7 ppm/°C can be obtained for specimen using (1 − x)Ca(Mg1/3Ta2/3)O3–x(Ca0.8Sr0.2)TiO3 (x = 0.4) sintered at 1425 °C for 3 h. It is proposed as a high-dielectric-constant, low-loss dielectric and in particular, a suitable candidate material for today's 3G passive components and small-sized GPS patch antennas.

Characterization and dielectric behavior of a new dielectric ceramics MgTiO 3–Ca 0.8Sr 0.2TiO 3 at microwave frequencies

The crystal structures, phase compositions and the microwave dielectric properties of the (1 − x)MgTiO 3– xCa 0.8Sr 0.2TiO 3 composites prepared by the conventional solid state route have been investigated. The formation of solid solution is confirmed by the XRD patterns. A rapid grain growth is observed at temperatures higher than 1300 °C, which would lead to a decrease in the density and Q × f of the ceramics. The temperature coefficient of resonant frequency ( τ f ) increases with increasing Ca 0.8Sr 0.2TiO 3 content and tunes through near zero at x = 0.06. Specimen using 0.94MgTiO 3–0.06Ca 0.8Sr 0.2TiO 3 possesses an excellent combination of microwave dielectric properties: ɛ r ∼21.9, Q × f ∼128,000 GHz and τ f ∼0.7 ppm/°C. It is proposed as a suitable candidate material for small-sized GPS patch antennas.