S-band Antenna Research Articles

A Reconfigurable Dual-Polarization Slot-Ring Antenna Element With Wide Bandwidth for Array Applications

A reconfigurable dual-polarized slot-ring antenna/array, switching between S- and C-band with wide bandwidth in each operating state is presented. By simultaneously switching eight p-i-n diode switches, a $2 \times 2$ C-band antenna array can be reconfigured to an S-band antenna unit cell, and vice versa. Fractal shapes are incorporated into the antenna structure to significantly enhance bandwidth. In the S-/C-band operating state, this antenna shows 69.1%/58.3% fractional bandwidth with a measured maximum realized gain of 2.4/3.1 dBi. For the $2 \times 2$ C-band array, the spacing between the elements is less than $0.5\lambda _{{0}}$ over the frequency band which enables grating-lobe-free beam scanning. A unidirectional version of this antenna/array with more than 12/16 dB front-to-back ratio at 3.5/8 GHz is also demonstrated. This wideband antenna/array can be used as a unit cell of a larger array with element spacing of half wavelength at the center frequency of both frequency bands.

Design of S-Band Antenna With L-Shaped Slits on Rectangular Patch With Defected Ground Structure

Monopole L-shaped slits are embedded on rectangular patch antenna is designed for S-band applications. The proposed antenna is a square patch radiator with four L-shaped slits are presented. The proposed antenna radiates at 3GHz resonance frequency with bandwidth of 1.9GHz and -26.4dB return loss. The impedance bandwidth is enhanced 62.7% with proposed antenna model. The proposed L-shaped slit patch antenna is small in size and compact. The radiation pattern is presented in the results and it works at S-band applications.

A Dual-Wideband Dual-Polarized Aperture-Shared Patch Antenna With High Isolation

A dual-wideband dual-polarized aperture-shared patch antenna with high isolation is proposed, which consists of an S-band circularly polarized antenna and an X-band linearly polarized antenna. The S-band antenna adopts the stacked patches, where the upper parasitic patch is introduced for increasing gain and bandwidth and also works as a ground plane for the X-band excited patch. The X-band feed coaxial line perforates the center of S-band excited patch and parasitic patch, so that the coshared aperture antennas are tightly integrated and have a high isolation. The simulated and measured results are matched well and show that the proposed antenna obtains 10 dB impedance bandwidths of 19.3% and 22%, peak gains of 10.8 dBi and 8.5 dBic, for X-band and S-band, respectively. Meanwhile, the 3 dB axial-ratio bandwidth of the S-band is 19.2% and the port isolation between S- and X-bands is higher than 32 dB.

Square‐shaped feeding truncated circularly polarised slot antenna

A novel S-band right handed circularly polarised (RHCP) slot antenna for supporting communication system of GAIA II/LAPAN-Chibasat is presented in this paper. This satellite implemented L-band Circularly Polarised Synthetic Aperture Radar (CP-SAR) sensor, X-band antenna is employed for mission data downlink and S-band antenna is employed for the command and telemetry. The S-band antenna is printed on the substrate with the relative permittivity of 2.17 and the thickness is 1.6 mm. A crescent shaped slot is placed on the ground plane. A square-shaped is set to strengthen the radiation on the edge of the feed-line. A parasitic strip rectangular-shaped is added on the ground plane to enhance the gain of the antenna. Truncation technique is employed to increase the bandwidth axial ratio(ARBW) and the gain. The total dimension of the antenna is 170 mm × 170 mm. The antenna produced <;3 dB bandwidth axial ratio of 14% and the bandwidth under -10 dB of return loss obtained 90%.The simulated and measured result of the antenna design is satisfied. Detail of the antenna design and the measurement result of the antenna are described and presented.

Lower mode excitation in vertex-fed slotted hexagonal S-band antenna

Direct-fed hexagonal patch antenna are limited to |S11| ≥ −10 dB at lower modes, especially when fed at the vertex of the hexagon. This paper demonstrates a technique to compensate impedance mismatch at a lower mode in a vertex-fed slotted hexagonal antenna. A circular parallel-plate capacitor (PPC) is introduced to the antenna structure that improves impedance matching to excite a lower mode for a probe-fed hexagonal patch antenna. With an overall size of 50 × 50 mm2, the proposed antenna is compact and can operate at 2.4 GHz in presence of PPC with a gain of 2.11 dB and is suitable for various S-band applications.

A Broad Beam-Width Dual-Polarization Microstrip Dipole Antenna for 5G MIMO Application

A novel S-band antenna is proposed in this paper. The antenna consists of two layers of radiant dipole. The unit is capable of realizing broad beam-width of 144° in E-plane with isolation better than -35dB between two ports. The circular polarization can be achieved by exciting two ports with equal amplitude and 90° phase difference. Moreover, the axial ratio is less than 2dB in the antenna operating frequency band. At last, a triangular grid array with 64 elements is designed. The simulated results show that the designed array can meet the requirements of large scanning angle. It can be applied for the fifth generation mobile communications (5G) Multiple-Input Multiple-Output (MIMO)base station.

Design and application of high‐power cavity‐backed helical antenna with unit ceramic radome

A high-power cavity-backed helical antenna with a unit ceramic radome is proposed and investigated for the first time. The helical antenna uses a unit ceramic radome to realise a vacuum seal for a single-element antenna, and the radome is designed in a thin-wall structure to maintain low insertion loss. The proposed antenna uses a backed cavity in a cylindrical structure to reduce the mutual coupling among elements. An S-band antenna prototype with a centre frequency of 2.856 GHz is designed and optimised. The performance of the antenna is simulated, including radiation performances and the power-handling capacity. This antenna is applied in an S-band 16-element sub-array and a 256-element array antenna. The experiment results validate that this antenna can realise favourable circularly polarised radiation in its axial direction in the frequency range of 2.7–3.0 GHz, and the average power-handling capacity for a single-element antenna is at least ∼4.7 MW.

발사체의 RF 호환성 시험을 위한 소형 S-밴드 안테나 햇

Abstract In this paper, we propose a compact antenna hat to perform RF compatibility testing efficiently between the launch vehicle and ground stations. The proposed structure implements a small size and low loss using the conductive shield instead of the conventional RF absorber. The S-band antenna hat, which is fabricated for an inverted-F onboard antenna with the size of 74 mm×13 mm×16 mm, has the small enclosure of 88 mm×35 mm×44 mm, the return loss of 25.6 dB, the insertion loss of 0.26 dB, and the leakage loss of 49.4 dB at the center frequency of 2.25 GHz. The simulated and measured results show a good agreement. Key words: Antenna Hat, Antenna Test Coupler, Launch Vehicle, RF Compatibility Testing, Telemetry 'Ÿ ‘ Ri(Korea Aerospace Research Institute) *¢£¤¥¦6p¥ (Department of Radio Science & Engineering, Chungnam National University)uManuscript received October 20, 2014 ; Revised December 12, 2014 ; Accepted December 23, 2014. (ID No. 20141020-085)uCorresponding Author: Dong-Chul Park (e-mail: dcpark@cnu.ac.kr)

Potential implications and road mapping of satellite bidirectional s-band antennas in the automotive market [antenna applications corner

Car radios were introduced for commercial (broadcast) and professional (communications) purposes in the 1920s [1]. This novelty was just one of many innovative technologies and products that were taken into mass production in passenger cars, and vehicles in general, since then [2, 3]. Wireless communications in particular nowadays represent an important business area for the automotive market, for “infotainment” (information and entertainment), comfort, environ mental, and safety-related services. In the field of connectivity - and specifically in the context of antennas for wireless functions - the case of the European satellite technology based on S band is analyzed here. The DVB-SH standard (Digital Video Broadcasting-Satellite Handheld [4]) is considered for the forward link, and the ETSI S-MIM standard (S-Band Mobile Interactive Multimedia [5, 6]) is considered for the return link. These standards can provide satellite services for mobile terminals, such as broadcasting of radio, TV, and data by using DVB-SH, and interactive services on the return link by using the ETSI S-MIM.

Interaction effect analysis of thruster plume on LEO satellite surface using parallel DSMC method

In the present study, the thruster plume interactions on a low earth orbit (LEO) satellite is investigated by predicting undesirable effects incurred by the plume impingement onto the satellite surface such as disturbance force/torque, thermal loading, and chemical species deposition. To predict the behaviors of thruster plume quantitatively, a numerical analysis with a parallel Direct Simulation Monte Carlo (DSMC) method using unstructured three-dimensional meshes is conducted. The interaction between the exhausted plumes from four monopropellant hydrazine thrusters and the satellite components, such as an S-band antenna, a launch vehicle adapter ring and solar arrays, are investigated. The analysis results verify that the exhausted thruster plumes provide the negligible influences of disturbance force/torque and thermal loading on the present LEO satellite configuration when compared with their values of nominal thrust/torque and solar heating. Also, the chemical species deposition of the thruster plume has no serious contamination due to its high surface temperature while only a large amount of H2 molecules is observed on the S-band antenna cone. From this study, the design configuration of the present LEO satellite is verified sufficiently by the numerical simulation of the plume interaction effects.

Design of a Printed Quadrifilar-Helical Antenna on a Dielectric Cylinder by Means of a Genetic Algorithm [Antenna Applications Corner

This paper presents the application of a genetic algorithm (GA) to the optimization of an S-band quadrifilar-helical antenna, which is printed on a dielectric cylinder. This antenna was designed for LEO satellite applications. Its saddle-shaped pattern should compensate for free-space loss variations in the satellite's footprint. The steady-state genetic algorithm was used for this optimization and an elitist strategy was implemented. The selection strategy in the present genetic algorithm was proportionate selection.

Prototype antenna elements for the next-generation TDRS enhanced multiple-access array

This paper summarizes a study performed to produce prototype antenna elements for the next-generation enhanced Tracking and Data Relay Satellite Continuation (TDRS-C) multiple-access (MA) S-band phased-array antenna. Compared to the multiple-access antenna on the current class of TORS, the enhanced multiple-access antenna requires elements that achieve greater on-axis gain, simultaneous circular polarization capability, and increased beamwidth. To demonstrate that array elements could be realized meeting these requirements, designs that were successful in simulation were fabricated and tested. These included a helical antenna; a novel short backfire antenna, excited with a circular waveguide (cup waveguide) with integrated polarizer and orthomode transducer (OMT); and a corrugated-horn antenna with integrated polarizer and OMVT. The paper describes the design process for the novel elements, and compares measured and simulated results. It also compares the elements in terms of performance, size, and mass.

S-band dual-path dual-polarized antenna system for satellite digital audio radio service (SDARS) application

This paper presents a novel compact dual-polarized antenna system for S-band satellite digital broadcasting receivers. The demonstrated antenna system consists of a low form factor dual-polarized antenna pair and two-stage low-noise amplifiers (LNAs) integrated with each antenna. One antenna is a low-profile annular ring patch antenna having a 90/spl deg/ phase-delay element for circular polarization (CP) and the other antenna is a reactively-loaded monopole antenna for linear polarization (LP). Both antennas operate in the same frequency range, from 2.320 to 2.345 GHz, while providing different polarizations to take advantage of the polarization diversity. Switches are used to select the mode (polarization) of operation. This ensures that appropriate dc bias is supplied to the operating LNA to process the received signal while no power is consumed by the idle LNA. The measured gains of the antenna system are 31.3 and 21.9 dBi for the CP and LP modes, respectively.

Micromachined S-band patch antenna with reduced dielectric constant

A generic dielectric constant reduction method for silicon substrates is presented in detail along with a process description to produce variable dielectric layers for planar antennas. Virtually any dielectric constant below the value for solid silicon 11.9 can be produced down to the limit of structural durability. A first-order volumetric average yields a dielectric constant of 3.8 for the following bonded micromachined silicon substrates; small honeycomb cells with wall thickness of 16 μm and inner wall length of 87 μm are etched using deep reactive ion etch (DRIE) to 475 μm depth in each of two 525 μm 4 in. high ohmic wafers. These two wafers are bonded together with the etched side of both wafers facing each other. A manufactured coaxial-fed disk-patch S-band antenna illustrates the method to reduce the dielectric constant for a circular zone with a diameter of 50 mm. The antenna is designed for a center frequency of 2.5 GHz based on a lossless substrate with a dielectric constant of 3.8. Adjusting the simulation model to fit the measured values of the antenna indicates a dielectric constant of 2.2, a dielectric loss tangent of 0.002, a bulk conductivity loss of 0.006 S/m, and a resonance frequency of 3.2 GHz. A low frequency analysis in the interval 200–500 MHz with a lumped element model and a low frequency formula for the capacitance between the patch and ground plane indicates a dielectric constant in the order of 2.7–2.8. Based on measurements in an SEM, a corrected average dielectric constant is found to be 2.9. This correction is due to thinner walls than expected in the manufactured honeycomb structure. Antenna lobe characteristics have been measured with a half-power beamwidth of ∼76° in both the E-plane and H-plane at 3.2 GHz.

Direct Simulation Monte Carlo Analysis of Thruster Plumes/Satellite Base Region Interaction

The interaction of thruster plumes with satellite components is investigated, with emphasis on undesirable effects, such as disturbance force/torque, thermal loading, and species deposition in the Korea Multipurpose Satellite-II (KOMPSAT-II) base region. The actual configuration of the satellite is simplified by the consideration of four major components of hydrazine thrusters, the S-band antenna, and the surrounding ring. For the numerical simulation, a fully unstructured three-dimensional discrete simulation Monte Carlo (DSMC) code is developed and validated. The DSMC computation allows for examination of the detailed flowfield dynamics, as well as the wall conditions, which, otherwise, would not be possible from a simplified engineering analysis. The computations show that the present thruster arrangement used in KOMPSAT-II incurs a negligible disturbance force/torque and thermal loading compared with its nominal thrust/torque and solar heating. The simulations also indicate that the species deposition is insignificant due to the high surface temperature of the satellite body. Of the chemical species considered (H2 ,N 2, and NH3), more H2 molecules collide with the S-band antenna cone. This study clearly shows the usefulness of DSMC calculations for analysis of plume effects in the development phase of a satellite.

KSR-3 비행시험 원격측정시스템 운용 결과

과학로켓3호(KSR-III) 비행시험시에 탑재용 원격측정장치는 로켓의 서브시스템들의 실시간 상태 및 각종 센서 자료를 획득하여 무선으로 전파 통신을 하고 지상에서 로켓을 추적하면서 비행중인 원격측정 데이터를 실시간으로 획득하고 복원하는 것은 로켓의 비행을 분석하는데 필수적이다. 또한 실시간으로 자료처리된 원격측정자료들은 네트워크를 통해 임무통제센터로 보내져 로켓의 비행 궤도를 도시하고 동시에 비행통제원이 로켓의 비행종단명령을 수행하기 위한 중요한 판단자료를 제공한다. 본 논문에서는 과학로켓3호 비행시험에 적합한 원격측정 수신과 관련된 운용기법 및 실시간 자료처리 시스템 개발에 관하여 기술하였으며 원격측정 수신결과를 분석하였다. 실제 비행시험시에 성공적으로 원격측정 수신 및 실시간 자료처리 임무를 완수하였다. Korea Sounding Rocket(KSR)-III onboard telemetry system has acquired various data from subsystems and sensors in the rocket, and radiated PCM/FM data using two S-band antennas during the flight. Simultaneously， it is necessary that the ground receiving systems track the rocket, and receive and decode telemetry data. Also post processed telemetry data are needed to be broadcasted on ethernet network in real time. Range safety display system displays flight trajectory using telemetry data in mission control center, and so flight manager makes a decision for flight termination from the trajectory This paper describes operating technique about telemetry reception, the development for the realtime data processing system, and the results for telemetering reception on fight test. We telemetered, processed, and broadcasted numerous telemetry data during the flight test successfully.

Key technologies for high-accuracy large mesh antenna reflectors

Nippon Telephone and Telegram Corporation (NTT) continues to develop the modular mesh-type deployable antenna. Antenna diameter can be changed from 5 m to about 20 m by changing the number of modules used with surface accuracy better than 2.4 mm RMS (including all error factors) with sufficient deployment reliability. Key technologies are the antenna's structural design, the deployment mechanism, the design tool, the analysis tool, and modularized testing/evaluation methods. This paper describes our beam steering mechanism. Tests show that it yields a beam pointing accuracy of better than 0.1°. Based on the S-band modular mesh antenna reflector, the surface accuracy degradation factors that must be considered in designing the new antenna are partially identified. The influence of modular connection errors on surface accuracy is quantitatively estimated. Our analysis tool SPADE is extended to include the addition of joint gaps. The addition of gaps allows non-linear vibration characteristics due to gapping in deployment hinges to be calculated. We intend to design a new type of mesh antenna reflector. Our new goal is an antenna for Ku or Ka band satellite communication. For this mission, the surface shape must be 5 times more accurate than is required for an S-band antenna.

Probability of error for BPSK modulation from electrostatic interference [in orbital situation

In an orbital situation any spacecraft is bombarded by charged particles that span a broad range of energies. Some of the particles may be trapped within the materials of the spacecraft. Recent data indicates that an S-band phased-array antenna on a spacecraft may experience electrostatic discharges from such ion deposition at the elements of the array. These discharges may induce RF interference of sufficient magnitude to degrade transponder performance. This issue is addressed by considering the degradation to a binary phase shift keying (BPSK) signal. A simple model for the electrostatic phenomenon is described, and error probabilities are evaluated. The discharges and induced pulse rates are shown to be well below the interference level.

Simulation diagnostics of multiple discontinuities in a microwave coaxial transmission line

Multiple discontinuities in microwave transmission lines can cause unusual reflection and transmission loss characteristics as functions of frequency. This article presents a method for developing models that simulate return loss and insertion loss data measured over a broad band of frequencies. The overall cable is modeled as a coaxial transmission line consisting of shunt susceptance discontinuities separated by line lengths. A nonlinear least-squares fit is then performed between theoretical data (from the model) and experimental data. When this method was applied to modeling discontinuities in a slightly damaged S-band antenna cable, excellent agreement between theory and experiment was obtained over a frequency range of 1.70-2.85 GHz.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Radio frequency fields generated by the S-band communication link onOV102

The Space Shuttle STS-3 mission carried a Plasma Diagnostics Package (PDP) whose instrumentation included an S-band antenna and detector. The PDP was maneuvered by the Remote Manipulator System arm through a computer controlled sequence in the Orbiter's X-Z plane, above the quad and hemi S-band communications antennas. Antenna field strength measurements were conducted during transmitter high power modes, and the results were compared to ground full scale measurements and predictions. A field strength 4.8 + or - 3 dB higher than predicted is noted. This RF field is primarily due to the quad PM transmitter, whose power output of 115 W compares with 15 W for the hemi.