Antenna For Satellite Communications Research Articles

Design of Compact Bow-Tie Slotted Antenna for Satellite Communication

A printed antenna using the slot-loading technique is adapted in the design to achieve multiband. A rectangular microstrip (printed) antenna with a Bow-Tie shape slot embedded on the radiating patch using a glass epoxy substrate with dimensions 3.34 x2.47 x 0.16 cms. The antenna is simulated using high-frequency structure simulator software and fabricated using a photolithography process. Experimental results are measured using a vector analyzer. the proposed antenna is resonating at three different frequencies 4.62 GHz, 8.14 GHz, and 12.41 GHz with a return loss of -20.00 dB, -25.09 dB, and -26.45 dB respectively. The antenna is resonating between 4.62 GHz to 12.41 GHz frequency which covers applications in the field of satellite (space to earth)5.441 and mobile communication 5.463.

A Dual Ka/Q-Band Reflectarray

Introduction. Duplex satellite communication is commonly arranged using two spaced frequency bands, with one band receiving and the other band transmitting signals to a satellite. The main task of a communications satellite antenna system consists in providing an identical coverage area across all involved frequency bands, which is often a challenging task for conventional parabolic reflector antennas. Reflectarrays allow an independent control of the reradiated wave phase in spaced frequency bands, which can be used to create efficient multi-band antenna systems for modern communication satellites.Aim. To develop a Ka/Q-frequency range phase-correcting element and to create on its basis a dual-band reflectarray for operation with orthogonal circular polarizations and identical gains in a given sector of angles in significantly spaced frequency ranges.Materials and methods. Numerical studies were carried out using the finite element analysis method. Radiation patterns were measured using the near field scanning method.Results. A single-layer dual-band phase-correcting reflectarray element was developed for operation with orthogonal circular polarizations with low losses and a weak dependence of the relative position of the elements on the phase characteristic. On the basis of the proposed element, a reflectarray consisting of 24 465 two-frequency elements was synthesized and manufactured. The developed prototype of a single-layer dual-band reflectarray demonstrated good characteristics, with the efficiency reaching 56 and 36 % in the Ka- and Q-frequency ranges, respectively, and an almost identical minimum gain in the ±0.75° angle sector.Conclusion. The research results confirm the potential of the developed reflectarray to successfully replace conventional parabolic reflectors installed both on modern communication satellites and as part of ground-based satellite terminals in the millimeter wavelength range.

Design of a Compact Reconfigurable Sierpinski Gasket Fractal Antenna for 5G and Satellite Communications

Reconfigurability is one of the key features of 5G/6G radiofrequency systems. The possibility to adapt the working frequency depending on the application or the status of the nodes is important, especially in Smart Radio Environments. In this regard, the design of antennas operating at different frequency bands is challenging since strict requirements on the footprints and the radiation properties are introduced. Among other geometries, fractals present unique features in terms of small electrical lengths: they have been used for years by researchers to shrink antenna dimensions in a very effective way. An interesting perspective of these antennas is the possibility to switch the working frequency among several bands connecting/disconnecting the fractal cells. The aim of this paper is the design and the optimization of an electrically reconfigurable Sierpinski gasket fractal antenna. Four different states are obtained: in the first the device works at 27 GHz (mmWave), in the second at 16 GHz, in the third at 11 GHz (Ku-band), and in the fourth at 3.5 GHz (Sub-6GHz). The antenna operates efficiently in all the bands of interest.

Vibrational characteristics of a helical antenna for L-Band satellite communications

Helical coils serve many functions in mechanical systems and are often subjected to a variety of impulsive forces. In this talk we examine the dynamics of a helix modeled after an L-Band helical antenna used for satellite communications in low Earth orbit (LEO). Since the components of a deployed satellite are not accessible, it is critical to understand the dynamics of the antenna given its position outside of the main body. The intent of this work is to identify the frequencies, shapes and Q-values of the vibrational modes of the helix subject to impulsive stimuli and evaluate changes due to environmental exposures and structural modifications. We report on coil-by-coil measurements of the spectra using eight distinct stimulus-response polarizations. Two specific studies are emphasized in this talk. To gauge the sensitivity of the element to thermal variations under (LEO) conditions, we report on the impact of thermal cycling on the vibrational spectra of the helix. We also report on changes in the dynamic response of the helix due to the addition of structural support elements.

Electromagnetic Performance of Waveguide Polarizers with Sizes Obtained by Single-Mode Technique and by Trust Region Optimization

Modern wireless networks, stationary terrestrial and satellite systems use many modern technologies to increase communication channels information capacity. They save limited frequency resources. In satellite communications the polarization signal processing is applied to reuse the allocated frequency bands. Usage of circularly polarized electromagnetic waves, which transmit useful signals, reduces fading effects and eliminates disadvantages introduced by multipath propagation interferences. In this case the distortion levels for signals with an odd number of electromagnetic waves reflections in the receiving antenna systems will be reduced down to the thresholds of their cross-polarization isolation. Besides, in the case of orthogonal polarizations usage, the achieved information capacity of the applied wireless communication channel multiples almost by the factor of two. The type of polarization of the used electromagnetic wave strongly determinates the peculiarities of the process of its propagation in the space or transmission line. Polarization signal processing is frequently carried out in horn feed systems of the reflector antennas. Such feed networks and systems allow to transmit and receive signals with several kinds of polarization at the same time. The fundamental element of dual circular polarization antenna feed networks is a waveguide polarization duplexer. The phase, isolation and matching characteristics of a polarization converter strongly influence on the functionality and polarization discrimination possibilities of the entire reflector antenna system. Therefore, the development and optimization of the characteristics of waveguide polarizers for satellite communication antennas is a crucial technical problem, which must be solved by fast and accurate methods. The comparison of electromagnetic performance of waveguide polarizers with sizes obtained using a fast single-mode technique and by more accurate trust region optimization method is carried out in this research. The results for differential phase shift, level of voltage standing wave ratio, ellipticity coefficient and cross-polarization discrimination are shown and discussed.

Low-RCS Ka-band receiving and transmitting satellite communication antennas co-designed with high-performance absorbent frequency-selective radomes

This paper investigates the low-RCS Ka-band receiving and transmitting satellite communication antennas co-designed with the high-performance absorbent frequency-selective radomes (AFSR). Consisting of the metamaterial absorber (MA) upper layer and bandpass FSS lower layer, two AFSRs operating at 19 and 29 GHz (receiving and transmitting central frequency) with low-frequency wideband absorbing and high-frequency low-insertion-loss transmission performances are proposed. To meet the needs of Ka-band satellite communication, two 4 × 4 microstrip array antennas working at the same central frequencies are co-designed with the AFSRs. We demonstrate the effectiveness of the proposed AFSRs and co-designed antenna through simulations and measurements. The results show that the gain degradations are only 0.44 dB and 0.58 dB at two central frequencies after loading the AFSRs separately, and 10-dB RCS reduction bandwidths are ranging from 6.1–16.3 GHz (relative bandwidth 91.1%) and 10.2–24.8 GHz (relative bandwidth 83.4%) individually.

New Reconfigurable Transmitarray Unit Cell Design at Ku-Band Using PIN Diodes

Beam reconfigurable Transmitarray antennas require the unit cell phase variation capability. This paper presents a new reconfigurable Transmitarray unit cell design using PIN diodes at the Ku-band. The unit cell is comprised of three layers having four PIN diodes used in every unit cell layer. This results in phase controlling by switching the PIN diodes on every layer individually. The unit cell s-parametric analysis shows a high transmission coefficient magnitude (> -3.6dB) at a design frequency of 12.5GHz and maximum wide impedance bandwidth (17.5%). Four different switching states configurations are used, which result in phase variations over the range of 150.5 degrees. The transmission coefficient magnitude remains high for all four switching states. The proposed reconfigurable unit cell can be used in designing beam switched Transmitarray antennas for satellite communications and beam steering applications.

Multifunctional Drone-Based Antenna for Satellite Communication

This communication presents a drone-to-satellite beam-forming antenna with multifunctional purposes. A glass material with a gradient coating configuration is exploited to realize a transparent structure. Beam tilting is obtained by controlling the phase distribution of an antenna by means of an inexpensive and passive surface. Simultaneously, solar cells are implemented on the proposed structure for solar energy harvesting using the transparency feature of the surface. The sputtering physical vapor deposition process is used to layer a thin coat of indium tin oxide (ITO) onto the glass. A conceptual beam tilting with a multipurpose design is introduced for drone2sat communication and energy harvest. The proposed communication structure works at a frequency of 3 GHz and covers a 60° spatial beamwidth. The directivity and propagation characteristics are preserved by this configuration. To validate the design performance, a prototype has been fabricated and a satisfactory agreement between the numerical results and experimental ones is achieved. The proposed structure can enhance the multifunctional designs, which could offer advantages for real-world space drone communications.

Microwave waveguide polarizer for satellite communication antennas with circular polarization

The volumes of information transmitted in modern satellite telecommunication systems are constantly increasing. Antennas with signal polarization processing, which is performed by polarizers, are the fundamental elements of such systems. Therefore, the development of methods for the analysis of new polarizers is an important problem. From a technological point of view, polarizers based on waveguides with irises are the simplest. Analysis and optimization of electromagnetic characteristics of a polarizer based on a square waveguide with irises are the goals of the presented research. To solve this optimization problem, we have created a new mathematical model, which allows investigating the influence of the design parameters of the polarizer on its electromagnetic characteristics. A mathematical model of the waveguide polarizer with irises was created by the method of decomposition using wave transmission and scattering matrices. Besides, the new mathematical model takes into account the thickness of the irises using their equivalent T- and П-shaped substitution circuits. The general wave scattering matrix is the basis of a new mathematical model of a waveguide polarizer. This matrix was determined using the theory of microwave circuits. The main characteristics of the waveguide polarizer were determined through the elements of this matrix. Here, we perform the optimization of the polarizer characteristics in the Ku-band 10.7–12.8 GHz. The developed new mathematical model of a waveguide polarizer with irises makes it possible to take into account the heights of the irises, distances between them and their thickness. The new mathematical model determines the electromagnetic characteristics of the polarizer in a simpler and faster way compared to the finite integration technique, which is often used for the analysis of microwave devices for various purposes

Low-Profile Dual-Band Circularly Polarized Antenna Combining Transmitarray and Reflectarray for Satellite Communications

This communication proposes a low-profile dual-band circularly polarized (CP) antenna for satellite communication at K- and Ka-bands. The antenna consists of a folded transmitarray (TA) operating at 20 GHz and a multi-feed reflectarray (RA) operating at 30 GHz. The dual split rings are used as the TA and RA elements. The TA is placed above the RA. The TA acts as the phase-controlling surface at 20 GHz and does not affect the transmission of plane waves at 30 GHz generated by the RA. The RA simultaneously serves as the phase-controlling surface at 30 GHz and as the ground for the folded TA at 20 GHz. Owing to the combination of the folded TA and multi-feed RA with a small focal length-to-diameter ratio, the antenna profile is reduced, and the height-to-diameter ratio is only 0.4. Compared with the traditional horn feed system, the CP patch arrays integrated on the TA surface are used as the feeds in this design. The orthomode transducer (OMT) and circular polarizer are not needed, which significantly saves space and cost. The antenna was manufactured and measured to verify its performance. The measured results keep good consistent with the simulated results.

Broadband Circularly Polarized Magnetoelectric Dipole Antenna and Array for K-Band and Ka-Band Satellite Communications

A circularly polarized (CP) magnetoelectric dipole (ME-dipole) antenna with a wide impedance bandwidth and 3 dB axial ratio (AR) bandwidth is proposed. The antenna is fed by a microstrip line and coupled through a modified cross-slot on the ground plane. Based on the conventional linearly polarized (LP) ME-dipole, the proposed electric dipoles and the coupling slots are modified to generate the CP radiation. Simulated results of the antenna element show an impedance bandwidth of 72.8% from 16.35 to 35.08 GHz and a 3 dB AR bandwidth of 39.2% from 21.53 to 30.07 GHz. To enhance the gain of the antenna for practical application, a 4 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 4 antenna array with full-corporate feeding network is designed, fabricated, and measured. The measured results show that an impedance bandwidth of 66.95% from 17.26 to 34.63 GHz and a 3 dB AR bandwidth of 41.1% from 19.25 to 29.25 GHz are achieved. The proposed antenna can be applied to K-band, Ka-band satellite communications or fifth-generation (5G) millimeter wave (mmWave) communications at n257 (26.5–29.5 GHz) and n258 (24.25–27.5 GHz) bands.

Multiband Slotted Crescent-shaped Patch Antenna for K-band Satellite and mmWave Communications

In this paper, a multiband miniaturized crescent-shaped patch antenna with circular slots is presented for ultra-wideband applications. The proposed antenna is constructed on a Flame Retardant 4 (FR-4) dielectric substrate. Next-generation wireless communication systems, such as beyond 5G (B5G) and 6G mobile communication systems require a wider bandwidth and higher data rates. The overall size of the proposed antenna is 11×9×2.4 ㎣ operating in the frequency range of 17.73 GHz to 26.04 GHz and 29.6 GHz to 31.02 GHz for satellite communications and radar systems, respectively, as well as 35.40 GHz to 38.65 GHz for future mmWave B5G mobile applications. These frequency ranges usually fall into the K-band and mmWave frequency spectrums. Simulation results demonstrate that the peak gain of the proposed antenna is 4.68 dB, which is obtained at 25 GHz.

Dual-Band Dual-Linearly/Circularly polarized Shared-Aperture antenna for satellite communication systems

This paper presents a dual-band dual-linear/circular-polarization shared-aperture antenna for satellite communication. The antenna has dual linear polarization (DLP) radiation performance in K-band and dual circular polarization (DCP) radiation performance in Ka-band. The four radiation patches cut by two slots in the linear polarization structure form a 2 × 2 circular polarization array. By cleverly combining DLP and DCP radiation elements in the substrate integrated waveguide (SIW), low profile and compact size structure are achieved. The proposed DLP and DCP shared-aperture antenna is fabricated by adopting a multilayer PCB technology. Measured results imply the operating bandwidths of 21.6–22.6 GHz and 20.7–22.6 GHz for horizontal polarization (HP) and vertical polarization (VP). Moreover, wide 3-dB axial ratio (AR) bandwidths of the DCP element are achieved, with the peak gain of 6.5 dBi and 7.4 dBi. The antenna with features of low frequency ratio shared-aperture, high polarization diversity and low cost is suited for the millimeter-wave satellite communication system.

Z-Shaped Metasurface-Based Wideband Circularly Polarized Fabry–Pérot Antenna for C-Band Satellite Technology

This research proposes a low-profile Z-shaped metasurface (MTS)-based wideband circularly polarized (CP) Fabry&#x2013;P&#x00E9;rot antenna for C-band satellite communication. The proposed low-cost and low-complexity CP Fabry&#x2013;P&#x00E9;rot antenna is realized by using three substrate layers: upper, middle, and lower. The substrates are of FR-4 type with a dielectric constant of 4.3 and loss tangent of 0.025. The upper substrate contains 9 &#x00D7; 9 periodically-arranged Z-shaped MTS unit cells functioning as the partially reflecting surface and circular polarization conversion, and at the center of the middle substrate sits a corners-truncated square patch. The lower substrate consists of a copper plate with an H-shaped slot at the center of the ground plane and a microstrip feed line. The lower and middle substrates function as the source antenna. The periodic Z-shaped MTS unit cells are utilized to enhance the impedance bandwidth (IBW) and gain of the source antenna and also to convert linearly polarized into CP wave. The antenna dimension is 1.5&#x03BB;0 &#x00D7; 1.5&#x03BB;0 &#x00D7; 0.51&#x03BB;0. Simulations are performed and experiments carried out. The measured IBW and axial ratio bandwidth are 64% (4.4 &#x2013; 7.6 GHz) and 18% (4.4 &#x2013; 5.3 GHz) at the center frequency of 5 GHz. In addition, the proposed antenna scheme achieves a measured 3-dB boresight gain bandwidth of 30% (4.3 &#x2013; 5.8 GHz) with the maximum gain of 12.88 dBic at 4.7 GHz, rendering the proposed Z-shaped MTS-based CP Fabry&#x2013;P&#x00E9;rot antenna operationally suitable for satellite communication. In essence, the novelty of this research lies in the use of the low-cost and low-complexity Z-shaped MTS unit cell to effectively enhance the antenna gain and convert LP into CP wave.

Wearable Metamaterial Dual-Polarized High Isolation UWB MIMO Vivaldi Antenna for 5G and Satellite Communications.

A low-profile Multiple Input Multiple Output (MIMO) antenna showing dual polarization, low mutual coupling, and acceptable diversity gain is presented by this paper. The antenna introduces the requirements of fifth generation (5G) and the satellite communications. A horizontally (4.8–31 GHz) and vertically polarized (7.6–37 GHz) modified antipodal Vivaldi antennas are simulated, fabricated, and integrated, and then their characteristics are examined. An ultra-wideband (UWB) at working bandwidths of 3.7–3.85 GHz and 5–40 GHz are achieved. Low mutual coupling of less than −22 dB is achieved after loading the antenna with cross-curves, staircase meander line, and integration of the metamaterial elements. The antennas are designed on a denim textile substrate with = 1.4 and h = 0.5 mm. A conductive textile called ShieldIt is utilized as conductor with conductivity of 1.8 × 104. After optimizing the proposed UWB-MIMO antenna’s characteristics, it is increased to four elements positioned at the four corners of a denim textile substrate to be employed as a UWB-MIMO antenna for handset communications, 5G, Ka and Ku band, and satellite communications (X-band). The proposed eight port UWB-MIMO antenna has a maximum gain of 10.7 dBi, 98% radiation efficiency, less than 0.01 ECC, and acceptable diversity gain. Afterwards, the eight-ports antenna performance is examined on a simulated real voxel hand and chest. Then, it is evaluated and compared on physical hand and chest of body. Evidently, the simulated and measured results show good agreement between them. The proposed UWB-MIMO antenna offers a compact and flexible design, which is suitably wearable for 5G and satellite communications applications.

A Low-Sidelobe-Level Variable Inclination Continuous Transverse Stub Antenna with a Nonlinear Slow-Wave Structure

The sidelobe level (SLL) is an essential performance factor for satellite communication antennas. A low-SLL design can effectively suppress adjacent satellite interference. A low-SLL design method for a variable inclination continuous transverse stub (VICTS) antenna is proposed in this paper. The VICTS antenna is composed of three rotatable parts: a feeding plate, a radiation plate, and a polarization plate. The radiation plate comprises two groups of stubs with different radiation ratios. Combined with the nonlinear slow-wave structure attached to the feeding plate, the radiation ratio of the unit can be adjusted. The aperture field of the VICTS antenna using this method can be tapered in order to suppress the SLL. To verify the effectiveness of this method, the antenna prototype is fabricated and measured in a microwave anechoic chamber. The simulation and the measurement are in good agreement. The reflection coefficient of the antenna is kept below −15 dB and between 13.75 GHz and 14.5 GHz. When the radiation plate and the feeding plate rotate relative to each other, the pattern beam can be scanned from 5° to 70 ° . In the scanning range, the typical SLL can reach −18 dB.

Bi‐objective control design for vehicle‐mounted mobile antenna servo systems

This paper studies a high-performance control design for the servo system of a vehicle-mounted mobile satellite communication antenna. Considering the different requirements for tracking and disturbance attenuation in the servo system, a novel controller structure consisting of a central controller and a disturbance filter is proposed. Based on this controller structure, a bi-objective control design scheme is proposed: One is an optimal tracking design for the central controller, and the other is a disturbance attenuation design for the disturbance filter. It turns out that the resulting control system achieves an optimal tracking performance when the external disturbance is at a low level; meanwhile, the system achieves a robust disturbance attenuation performance when the disturbance is significant. Moreover, considering the trade-offs between performance and the robust stability of the closed-loop system, the weighting parameter selection in control design criteria is studied for a practical application. Furthermore, validation experiments and field tests are carried out to evaluate the effectiveness of this design, and their results show that the well-designed bi-objective controller significantly improves the dynamic pointing accuracy of the antenna in tracking a geostationary satellite when its carrier is driving off-road.

Amplification of High Quality of Signal Strength Using Corner Reflector Antenna for Satellite Communications

The strengths of the corner reflector antenna (CRA) which spans space's dynamic pseudo-random phase wave-front, which can be used in frequency modulation of the echo, replacing doppler's typical style. Radiometric assumes that Imaging discoveries can change lives a kind of special geosynchronous in geostationary orbit for the extremely low SNR in this geometry, just have a very low signal to noise ratio (SNR) posit the use of such a matched filter to strengthen the SNR and enable the existence of good specificity. In this paper, the signal is amplified to send a high-quality signal to the transmitter for satellite communication using a corner reflector antenna. Apart from other antennas, the corner reflector antenna plays an important role in increasing the signal strength in satellite communication. Using this corner reflector antenna the system will be good and fast so that the transmitter or the receiver can transmit or receive the signal very fast. While transmitting the signal the noise or interference in the system can be eliminated for that reason the corner reflector antenna is used. The corner reflector antenna can reduce the system noise or interference so that the system will be in proper condition to transmit or receive the signal.

Development of a phased array antenna powered by Rotman printed lens for a mobile satellite communication terminal

Connecting to the Internet whenever and wherever you travel is no longer a luxury. All people have the ability to connect to the Internet and share data away from home. Satellite communications are now an integral part of successful and high-quality communications. Satellite communications antennas are usually installed on mobile ground terminals. Due to its wide coverage and versatility, satellite communications are continuously improving and adapting to the telecommunications needs of many countries, despite the fact that broadband, Internet and fiber - optic communications are used almost everywhere. We know that more than 50 % of all satellites in orbit are communications satellites.

Design and Realization of an UHF Frequency Reconfigurable Antenna for Hybrid Connectivity LPWAN and LEO Satellite Networks.

UHF satellite communication for Internet of Things (IoT) technology is rapidly emerging in monitoring applications as it offers the possibility of lower-costs and global coverage. At the present time, Low Power Wide Area Network (LPWAN) solutions offer low power consumption, but still suffer from white zones. In this paper, the authors propose an UHF frequency reconfigurable Antenna for hybrid connectivity LoRaWAN (at 868 MHz) and UHF satellite communication (Tx at 401 MHz and Rx at 466 MHz) with the Low Earth Orbit (LEO) Kineis constellation. The antenna is based on a meandered line structure loaded with lumped components and a PIN diode to control the antenna resonant frequencies. It resonates at 401 and 868 MHz when the PIN diode is forward-biased (ON state) and 466 MHz in reverse-biased configuration (OFF state). The antenna is designed inside the enclosure with the presence of all the parts of the connected device. The results of EM simulations and parametric studies on the values of the lumped components and the PIN diode equivalent model, which are obtained with HFSS, are presented. The antenna is prototyped and has dimensions of 78 mm × 88 mm × 1.6 mm. The paper proposes a fast and practical method to reduce time development and compensate the frequency shift between measurement and simulation.