Antenna For Satellite Communications Research Articles

Evaluation of nanoalumina coated germanium black polyimide membrane as sunshield for application on the communication satellite antenna

Alumina thin coatings were grown on Germanium (Ge) coated black polyimide (GBP) or Kapton which has been used as a sunshield membrane on communication satellite antennas to protect it from environmental degradation during ground storage and implementation. The deposited nanoalumina coatings were found to be optically transparent in solar regime in spectral window while RF characteristic revealed negligible losses. Space worthiness of the coating was examined by simulated environments, e.g. humidity, thermal cycling and thermovacuum tests. No degradation was observed in its microstructural, thermo-optical, electrical, chemical state and RF characteristic in particular Ku and Ka bands. The aforesaid study indicates that the alumina thin coating is able to prevent surface degradation of GBP retaining the thermo-optical properties of the Ge coated Kapton and RF transparency which are functional requirements for communication antenna. The thickness of the optimized alumina coating was ~60nm.

A resonant circular polarization selective structure of closely spaced wire helices

AbstractA circular polarization selective structure (CPSS) reflects one handedness of circular polarization and transmits the other. We present a resonant CPSS consisting of closely spaced wire helices. Simulation results demonstrate that the design can operate over ±20° angle of incidence variation and has a bandwidth of about 10% at normal incidence. A suggested design case is presented, where the CPSS is implemented in a shared aperture circular polarization offset reflector antenna for satellite communication in the Ku band uplink of Australia at 17.3 GHz < f < 18.1 GHz.

위성통신용 삼중대역 동시사용 안테나 설계

As satellite communications services are showing gradual growth, so are the needs for dual or tri-band antennas greater than performance of conventional single-band antennas. In this paper, a simultaneously operable tri-band antenna for SATCOM(Satellite Communications) is proposed. It is different from conventional methods of implementing tri-band through replaceable horns, while it is designed with a tri-band feed assembly composed of corrugated and dielectric horns and reflectors of gregorian type to transmit and receive tri-band of X, Ku and Ka band simultaneously. And simulated and measured values were compared and analyzed for characteristics of the proposed antenna. In the results, radiation patterns of the proposed tri-band antenna were close to the simulated ones and also met specifications.

A Transportable Reflectarray Antenna for Satellite Ku-band Emergency Communications

The design of a Ku-band reconfigurable reflectarray antenna for emergency satellite communications is presented. Bidirectional high data rate satellite links are needed in emergency conditions where other telecommunication infrastructures are not available. In order to operate in this type of scenario, an antenna should be deployable, transportable, and easily repointable. The need of an automatic and fast satellite location and pointing system leads to a completely electronic reconfigurable antenna. The operative bandwidth is from 10.7 to 12.5 GHz for reception and from 14 up to 14.5 GHz for transmission (30% of relative bandwidth). The selected antenna architecture is based on a dual reflectarray system comprising a passive subreflectarray and an active main reflectarray made of reconfigurable 1-bit elementary cells based on PIN diodes.

Guest Editorial Antennas for Satellite Communications

The objective of this special issue is to bring together the most updated research contributions addressing antennas for satellite communications (both spaceborne and user terminals), and propose new applications, solutions, and challenges for the future.

A Novel Hybrid Phased Array Antenna for Satellite Communication on-the-Move in Ku-band

This paper introduces a novel waveguide hybrid phased array (HPA) for mobile satellite communications operating in Ku-band. The array is low profile and low cost, adopting an electrical scan in elevation and mechanical scan in azimuth to track satellites. High directivity and wide bandwidth impedance is provided by a dual linear polarized waveguide radiating element that covers both Rx and Tx frequencies within the band. The vertical and horizontal polarizations are excited by direct feeding and slot coupled aperture feeding, respectively. The array structure of $32 \times 12$ elements is split into inclined and interlaced 12 subarrays 225 mm in height. The feed networks and duplexers are designed in unconventional waveguide sizes. In the system, there are 12 independent receiving (Rx) and transmitting (Tx) modules with phased shifter components, which realize beam and polarization tracking. The system is designed to track satellites by scanning $15^\circ{-}75^\circ$ (relative to the ground plane) electrically in the elevation and $0^\circ{-}360^\circ$ mechanically in the azimuth. The array has been successfully developed and measured. The maximal gain loss in scanning range is about 4.0 dB.

Tx-Rx Lens-Based Satellite-on-the-Move Ka-Band Antenna

A simple low-cost mobile ground terminal antenna for Ka-band satellite communications is presented. The antenna is composed of a shaped dielectric lens which tilts and rotates in front of a feed to direct the beam. The wideband feed system is composed of a quad-ridged horn with a $45^{\circ}$ slant aperture and a coaxial-to-quad-ridged circular waveguide transition. The lens allows simple mechanical beam steering from 0 $^\circ $ to 65 $^\circ $ in relation to the zenith and 360 $^\circ $ in azimuth by rotating both the lens and the feed slanted aperture. Performance measurements of a manufactured prototype prove the beam tilting capabilities in elevation with a maximum gain of 22 dBi and scan loss below 3 dB at 20 GHz and 24 dBi gain with less than 4.5 dB scan loss at 30 GHz.

Evolution of Satellite Communication Antennas on Mobile Ground Terminals

Getting connected whenever and wherever you travel is not kind of luxury any more. Satellite communication researchers are making it a reality to bring you data, video, and voice services when you are away from home, out of office, or on a long journey. Satellite communication antenna mounted on mobile ground terminals is an essential prerequisite of successful connectivity. In this paper, we review the evolution of this kind of antenna in its historical context and outline the major research achievements on ground mobile terminals. Many striking demonstrations and prototypes are revisited to understand the emerging technologies and assess their potential towards practical implementations. The future trends and challenges are also discussed.

Planetary gearbox condition monitoring of ship-based satellite communication antennas using ensemble multiwavelet analysis method

Satellite communication antennas are key devices of a measurement ship to support voice, data, fax and video integration services. Condition monitoring of mechanical equipment from the vibration measurement data is significant for guaranteeing safe operation and avoiding the unscheduled breakdown. So, condition monitoring system for ship-based satellite communication antennas is designed and developed. Planetary gearboxes play an important role in the transmission train of satellite communication antenna. However, condition monitoring of planetary gearbox still faces challenges due to complexity and weak condition feature. This paper provides a possibility for planetary gearbox condition monitoring by proposing ensemble a multiwavelet analysis method. Benefit from the property on multi-resolution analysis and the multiple wavelet basis functions, multiwavelet has the advantage over characterizing the non-stationary signal. In order to realize the accurate detection of the condition feature and multi-resolution analysis in the whole frequency band, adaptive multiwavelet basis function is constructed via increasing multiplicity and then vibration signal is processed by the ensemble multiwavelet transform. Finally, normalized ensemble multiwavelet transform information entropy is computed to describe the condition of planetary gearbox. The effectiveness of proposed method is first validated through condition monitoring of experimental planetary gearbox. Then this method is used for planetary gearbox condition monitoring of ship-based satellite communication antennas and the results support its feasibility.

Discrete-dipole approximation model for control and optimization of a holographic metamaterial antenna.

Since the discovery of materials with negative refractive index, widely known as metamaterials, it has been possible to develop new devices that utilize a metamaterial's ability to control the path of electromagnetic energy. Of particular promise, and already under intensive development for commercial applications, are metamaterial antennas for satellite communications. Using reconfigurable metamaterials in conjunction with the principles of holography, these new antennas can electronically steer the high gain antenna beam required for broadband communications while not having any moving parts, being thinner, lighter weight, and less expensive, and requiring less power to operate than conventional alternatives. Yet, the promise of these devices will not be realized without efficient and effective control and optimization. Toward this end, in this paper a discrete-dipole approximation (DDA) model of a waveguide-fed planar metamaterial antenna is derived. The proposed model is demonstrated to accurately predict the radiation of a two-dimensional metamaterial at a much reduced computational cost to full-wave simulation and at much greater fidelity than simpler models typically used in the field. The predictive capabilities of the derived DDA model opens possibilities for model-based control design for optimal beam steering.

Design of circular spiral antenna for mobile satellite communication

This paper presents the simulation, design, and fabrication of a circular spiral antenna for mobile - satellite communication with wide bandwidth. The center frequency is 1.78 GHz with the bandwidth is 60 MHz radiation pattern of this antenna shows bidirectional pattern with voltage standing wave ratio of less than two, return loss of less than -10 dB, the line impedance of 50 Ω . All the design and simulation of this Antenna is carried by using a commercial CST simulator. The antenna is fabricated on Fr-4 substrate with 4.3 dielectric constant and 1.6 mm of thickness. Transient solver is used to measure all the parameters of this Antenna. It is observed that the simulated and measured values of the parameters of the antenna were quite close with each other.

Antennas for Satellite Communication

Satellite communication antenna in unvield .It also comprises of transmitting/ receiving signal section and transmission of signal to satellite . it consist of various types of antennas used in satellite communication such as UHF, L/s band ,c-band, ku-band , k-band antennas. Multibeam broadband antenna and antennas for geostationary for satellite communication is also explained in this paper . This paper mainly describes the the signal transmitting/receiving antennas for satellite communication .

Wideband Circularly Polarized Microstrip Antenna With Wide Beamwidth

A novel wideband circularly polarized antenna for S-band satellite communications with wide beamwidth is presented. The wide impedance bandwidth is achieved by using the modified inverted-L feeds and stacked patches. The wide beamwidth is obtained by the semi-open metal cavity. A prototype of the antenna is implemented, and the measured bandwidth is 30.1% with the reflection coefficient <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\leq \hbox{-}10~\hbox{dB}$</tex> </formula> , axial ratio <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\leq 3~\hbox{dB}$</tex></formula> , half-power beamwidth (HPBW) <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$\geq 100^\circ $</tex></formula> , and gain <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$\geq 3~\hbox{dBic}$</tex></formula> . Experimental results show that the proposed antenna has good impedance matching, circular polarization, and wide beamwidth characteristics.

무궁화 5호 위성통신용 Ka대역 안테나 설계

In this paper, we have designed the antenna for Korea SAT-5 Satellite Communication which can use Ka band in the earth station. The antenna structure consist of the the dual-offset gregorian reflector that has high gain and efficiency, the corrugatedhorn that has symmetric radiation patterns and low side lobe levels, the iris polarizer thatmake circular polarization and the OrthoMode Transducer that separate transmitting and receiving signals. The designed antenna gain is more than 45.7㏈i in Tx-band which use LHCP and 42.0㏈i in Rx-band which use RHCP. The co-polarized and cross-polarized radiation pattern comply with ITU-R S.580-6 and S.731-1 that are recommended by International Telecommunication Union in the geostationary satellite. The Axial ratio is less than 1.0㏈ in Tx-band and 1.5㏈ in Rx-band that meet MIL-STD-188-164A.

Call for Papers - Special Issue on Antennas for Satellite Communications

Call for Papers - Special Issue on Antennas for Satellite Communications

능동위상배열 안테나를 위한 Ka-대역 8채널 송신능동모듈 설계

This paper presents the 8-channel active module operated in Ka-band. The module is designed for the mobile satellite communication antenna systems, and the module structure has the merit to minimize the size and weight of the antenna systems by 30% compared with the conventional systems using the active module composed of single channel. This module was designed to be optimally operated by prohibiting the electrical interference among the individual channels. From the test results of the fabricated 8-channel active module, it can be confirmed that the maximum channel gain error is , the minimum channel output power is 21.5dBm, and the maximum gain variation by phase control is .

Customized Multiwavelets for Planetary Gearbox Fault Detection Based on Vibration Sensor Signals

Planetary gearboxes exhibit complicated dynamic responses which are more difficult to detect in vibration signals than fixed-axis gear trains because of the special gear transmission structures. Diverse advanced methods have been developed for this challenging task to reduce or avoid unscheduled breakdown and catastrophic accidents. It is feasible to make fault features distinct by using multiwavelet denoising which depends on the feature separation and the threshold denoising. However, standard and fixed multiwavelets are not suitable for accurate fault feature detections because they are usually independent of the measured signals. To overcome this drawback, a method to construct customized multiwavelets based on the redundant symmetric lifting scheme is proposed in this paper. A novel indicator which combines kurtosis and entropy is applied to select the optimal multiwavelets, because kurtosis is sensitive to sharp impulses and entropy is effective for periodic impulses. The improved neighboring coefficients method is introduced into multiwavelet denoising. The vibration signals of a planetary gearbox from a satellite communication antenna on a measurement ship are captured under various motor speeds. The results show the proposed method could accurately detect the incipient pitting faults on two neighboring teeth in the planetary gearbox.

Design and Optimization of a Compact Wideband Hat-Fed Reflector Antenna for Satellite Communications

We present a new design of the hat-fed reflector antenna for satellite communications, where a low reflection coefficient, high gain, low sidelobes and low cross-polar level are required over a wide frequency band. The hat feed has been optimized by using the Genetic Algorithm through a commercial FDTD solver, QuickWave-V2D, together with an own developed optimization code. The Gaussian vertex plate has been applied at the center of the reflector in order to improve the reflection coefficient and reduce the far-out sidelobes. A parabolic reflector with a ring-shaped focus has been designed for obtaining nearly 100% phase efficiency. The antenna's reflection coefficient is below -17 dB and the radiation patterns satisfy the M-x standard co- and cross-polar sidelobe envelopes for satellite ground stations over a bandwidth of 30%. A low-cost monolayer radome has been designed for the antenna with satisfactory performance. The simulations have been verified by measurements; both of them are presented in the paper.

High-Gain Planar Antenna Arrays for Mobile Satellite Communications [Antenna Applications Corner

Two large and low-profile panel antenna arrays, used as receiving and transmitting antennas for mobile satellite communications, are described. The receiving and transmitting arrays have overall dimensions of 120 cm × 20.7 cm × 1.3cm and 107.5 cm × 20.4 cm × 1.7 cm, respectively. They exhibit high gains and adequate efficiencies, due to integrated array designs. For the receiving panel array, a method using a number of high-efficiency subarrays, combined with a novel active integrated global feed network, is proposed. For the transmitting panel array, a number of high-efficiency subarrays, together with a novel compact waveguide feed network, is employed. Based on the above techniques, two large panel antenna arrays were successfully developed. We present the detailed designs of the subarrays, the passive and active feed networks, and the vertical transitions. Simulated and experimental results showed that the designed receiving and transmitting panel arrays achieved measured gains and efficiencies of 34.1 dBi and 48.2%, and 33.5 dBi and 36.3%, respectively, in each band. This indicated that the proposed antenna panels are good candidates for future satellite communications applications.

Ka/S dual‐band antenna for satellite communication

AbstractA novel space‐borne Ka/S dual‐band antenna is proposed in this article, in which the waveguide TE21‐mode automatic tracking is used for the Ka‐band.The two bands are common in structure but independent from each other electrically, thus the installation space specifications of the satellite platform can be met. The antenna design procedures as well as the measurement results are presented. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1246–1251, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26791