Conformal phased array with beam forming for airborne satellite communication

For enhanced communication on board of aircraft novel antenna systems with broadband satellite-based capabilities are required. The installation of such systems on board of aircraft requires the development of a very low-profile aircraft antenna, which can point to satellites anywhere in the upper hemisphere. To this end, phased array antennas which are conformal to the aircraft fuselage are attractive. In this paper two key aspects of conformal phased array antenna arrays are addressed: the development of a broadband Ku-band antenna and the beam synthesis for conformal array antennas. The antenna elements of the conformal array are stacked patch antennas with dual linear polarization which have sufficient bandwidth. For beam forming synthesis a method based on a truncated Singular Value Decomposition is proposed

Wideband and UWB antennas for wireless applications. A comprehensive review

A comprehensive review concerning the geometry, the manufacturing technologies, the materials, and the numerical techniques, adopted for the analysis and design of wideband and ultrawideband (UWB) antennas for wireless applications, is presented. Planar, printed, dielectric, and wearable antennas, achievable on laminate (rigid and flexible), and textile dielectric substrates are taken into account. The performances of small, low-profile, and dielectric resonator antennas are illustrated paying particular attention to the application areas concerning portable devices (mobile phones, tablets, glasses, laptops, wearable computers, etc.) and radio base stations. This information provides a guidance to the selection of the different antenna geometries in terms of bandwidth, gain, field polarization, time-domain response, dimensions, and materials useful for their realization and integration in modern communication systems

Antennas for mobile satellite communications

A NASA sponsored program, called the Mobile Satellite (MSAT) system, has prompted the development of several innovative antennas at L-band frequencies. In the space segment of the MSAT system, an efficient, light weight, circularly polarized microstrip array that uses linearly polarized elements was developed as a multiple beam reflector feed system. In the ground segment, a low-cost, low-profile, and very efficient microstrip Yagi array was developed as a medium-gain mechanically steered vehicle antenna. Circularly shaped microstrip patches excited at higher-order modes were also developed as low-gain vehicle antennas. A more recent effort called for the development of a 20/30 GHz mobile terminal antenna for future-generation mobile satellite communications. To combat the high insertion loss encountered at 20/30 GHz, series-fed Monolithic Microwave Integrated Circuit (MMIC) microstrip array antennas are currently being developed. These MMIC arrays may lead to the development of several small but high-gain Ka-band antennas for the Personal Access Satellite Service planned for the 2000s

A Stacked Microstrip Antenna Array with Fractal Patches

A novel microstrip antenna array, which utilizes Giuseppe Peano fractal shaped patches as its radiation elements and adopts a two-layer stacked structure for achieving both wideband and high-gain properties, is proposed. Parametric study estimates that the proposed antenna’s size can be arbitrarily adjusted by changing the fractal proportion while high aperture efficiency is maintained. Two prototypes with 2 × 2 and 4 × 4 fractal patches, respectively, on each layer are designed, fabricated, and measured. Both simulation and measurement results demonstrate that the proposed antenna possesses encouraging performances of wideband, high directivity, and high aperture efficiency simultaneously; for example, for the two prototypes, their S11<-10 dB impedance bandwidths are 23.49% and 18.49%, respectively; at the working frequency of 5.8 GHz, their directivities are 12.2 dBi and 18.2 dBi, and their corresponding aperture efficiencies are up to 91.0% and 90.5%, respectively

Substrate Integrated Waveguide fed Wideband Circularly Polarised Antenna with Parasitic Patches

In this study, a wideband circularly polarised (CP) antenna is developed and demonstrated. The antenna comprises of two-layered substrates, the top layer holds a driven patch and eight surrounding parasitic patches of similar dimensions, and substrate integrated waveguide (SIW) based feeding topology is designed at the bottom layer. The driven patch is excited through coupling mechanism using a cross-slot carved on the upper clad of the SIW. The corners of the driven patch are curtailed and arms of the coupling slot made unequal, which constructively generates the CP wave. Moreover, the proposed antenna is prototyped, and experimentally verified. The antenna shows measured impedance and axial-ratio (AR) bandwidths of 1.29 GHz (21 per cent) and 460 MHz (7.35 per cent), respectively, while maintaining the high gain of ~8 dBic over the operating CP region. This design aids the favorable characteristics such as light weight, wide impedance and (AR) bandwidths, high-gain as well as lenience of production, and integration

Statistical Review Evaluation of 5G Antenna Design Models from a Pragmatic Perspective under Multi-Domain Application Scenarios

Antenna design for the 5G spectrum requires analysis of contextual frequency bands, design of miniaturization techniques, gain improvement models, polarization techniques, standard radiation pattern designs, metamaterial integration, and substrate selection. Most of these models also vary in terms of qualitative &amp; and quantitative parameters, which include forward gain levels, reverse gain, frequency response, substrate types, antenna shape, feeding levels, etc. Due to such a wide variety in performance, it is ambiguous for researchers to identify the optimum models for their application-specific use cases. This ambiguity results in validating these models on multiple simulation tools, which increases design delays and the cost of deployments. To reduce this ambiguity, a survey of recently proposed antenna design models is discussed in this text. This discussion recommended that polarization optimization and gain maximization are the major impact factors that must be considered while designing antennas. It is also recommended that collocated microstrip slot antennas, fully planar dual-polarized broadband antennas, and real-time deployments of combined slot antenna pairs with wide-band decoupling are very advantageous. Based on this discussion, researchers will be able to identify optimal performance-specific models for different applications. This discussion also compares underlying models in terms of their quantitative parameters, which include forward gain levels, bandwidth, complexity of deployment, scalability, and cost metrics. Upon referring to this comparison, researchers will be able to identify the optimum models for their performance-specific use cases. This review also formulates a novel Antenna Design Rank Metric (ADRM) that combines the evaluated parameters, thereby allowing readers to identify antenna design models that are optimized for multiple parameters and can be used for large-scale 5G communication scenarios

A Wideband Reconfigurable Antenna with 360° Beam Steering for 802.11ac WLAN Applications

© 1963-2012 IEEE. A novel 360° beam steering patch antenna with parasitic elements is presented in this paper. The designed antenna consists of a radiating patch and six parasitic elements, each of which is connected through a group of shorting vias controlled by p-i-n diode switches. By switching on the desired groups of the shorting vias, the electric field distribution inside substrate cavity appears at the desired beam direction. Rotationally switching on the groups of the shorting vias, the performance of 360° beam scanning is realized. To further understand operating mechanism, the antenna is modeled with equivalent circuit in terms of the on and off status of a sector of the antenna, which can be used as a design guide for shorting-vias-controlled reconfigurable microstrip patch antennas. The fabricated antenna achieves a bandwidth of 14.5%, a peak gain of 10 dBi, and the efficiency of 80.5%. The achieved beamwidths are 42° and 97° in azimuth and elevation planes, respectively. With an ability of being steered around zenith axis at six directions, the scanned beam range covers the entire 360°. The physical dimension is only 2.5 λg for the size and 0.5λg for the profile. This antenna operates from 5.1 to 5.9 GHz and has significant meaning in the IEEE 802.11ac wireless local area network applications due to its capabilities of generating 360° steered beams

Gain Enhancement of a Wide Slot Antenna Using a Second-Order Bandpass Frequency Selective Surface

Gain enhancement of a wide slot antenna over a wide frequency band using a low profile, second order bandpass frequency selective surface (FSS) as a superstrate is presented in this paper. The proposed multilayered FSS with non-resonant unit cells in each layer allows in-phase transmission of waves radiated from the antenna over a 3dB bandwidth of about 50%. The design allows an enhancement of upto 4dBi in the antenna gain over the entire frequency band (5-8GHz) of operation. The FSS provides a very low insertion loss between the two transmission poles along with a linearly decreasing transmission phase over the band. The composite structure shows an impedance bandwidth (-10dB) of 65% with an average gain between 6-8dBi over the frequency band with a peak gain of 9dBi. Measurement results of the fabricated prototype matches well with the predicted values

Reconfigurable microstrip antennas with tunable radiation pattern characteristics

Reconfigurable beam antenna systems are capable of changing their radiation characteristics in real time, such as beam direction, beam shape, beamwidth, etc. Such antenna system is desired for various wireless applications because of many reasons among them; it helps to enhance signal strength received from an intended target, mitigates interference, and accommodates sudden changes in traffic demand of wireless networks. It might also help to reduce the deployment cost of wireless networks infrastructures. In this dissertation, designs for reconfigurable beam microstrip antennas with tunable radiation characteristics have been proposed. The method to achieve these designs is the reconfigurable parasitic element (s) of tunable electrical size, placed in close proximity to the driven patch. A tuning mechanism with the aid of Varactor diodes is introduced for the parasitic patch that effectively allows for controlling its electrical size. This (these) reconfigurable parasitic patch (es) is (are) then applied in different fashions to devise several antenna designs with dynamic electronic control over certain radiation specifications. The accomplished antenna designs in the dissertation are: * Circularly polarized (CP) beam scanning antenna, where two elements microstrip Yagi-Uda antenna is used. The first element is a square patch driven with two probe feeds of quadrature phase for CP excitation. The second element is a parasitic square patch with narrow square-shaped slot carved on its surface. The parasitic patch is adjacent to the driven patch with a small separation distance. Four varactor diodes are placed on the middle of each side of the square slot to facilitate tuning of its electrical size. The parasitic patch electrical size is alloto be effectively tuned by varying the applied reverse biasing DC voltage to the varactors (capacitance value). The CP beam direction is scanned from -36° to 32° with gain variation from 5.7 to 8.2 dBic, and efficiency from 54% to 75.58% along the scanning range. * Two-dimensional beam scanning antenna, where two orthogonal crossed Yagi-Uda antenna configuration is utilized. The driven element is a square patch excited with a probe coaxial feed. The other two parasitic patches are closely placed along the E & H planes of the driven patch. Each parasitic patch has a narrow rectangular slit at its center, where a varactor diode is placed to allow for tuning its electrical size. The beam direction is permitted to be scanned in both the elevation and azimuth planes. The achieved scan range in the elevation plane is from 0° to 32°, whereas in azimuth plan is from 0° to 90°. Along the scanning range, the attained gain changes from 8.1 to 8.9 dBi, and efficiency changes from 86% to 93%. * Tunable beamwidth antenna, with a dynamic control over the radiation beam focusing is proposed. The antenna consists of a square patch excited by a coaxial probe feed, and other two square parasitic patches placed on both sides of the driven along its H-plane. Each parasitic patch has a narrow slit at its center loaded with lumped varactor diode to tune its electrical size. Upon changing the parasitic patches size, the antenna effective aperture is altered, and hence the beamwidth in the H-plane is controlled. The achieved beamwidth tuning range is from 52° to 108°, whereas the gain changes from 6.5 to 8.1 dBi. Throughout the dissertation, 2.45 GHz is chosen, as an example, to be the target frequency. All the designs are validated through experimental measurements for fabricated prototypes, and good agreement is observed between the predicted and measured results

Small Footprint Multilayered Millimeter-Wave Antennas and Feeding Networks for Multi-Dimensional Scanning and High-Density Integrated Systems

This paper overviews the state-of-the-art of substrate integrated waveguide (SIW) techniques in the design and realization of innovative low-cost, low-profile and low-loss (L3) millimeter-wave antenna elements, feeding networks and arrays for various wireless applications. Novel classes of multilayered antenna structures and systems are proposed and studied to exploit the vertical dimension of planar structures to overcome certain limita-tions in standard two-dimensional (2-D) topologies. The developed structures are based on two techniques, namely multi-layer stacked structures and E-plane corners. Differ-ent E-plane structures realised with SIW waveguide are presented, thereby demonstrating the potential of the proposed techniques as in multi-polarization antenna feeding. An array of 128 elements shows low SLL and height gain with just 200g of the total weight. Two versions of 2-D scanning multi-beam are presented, which effectively combine frequency scanning with beam forming networks. Adding the benefits of wide band performance to the multilayer structure, two bi-layer structures are investigated. Different stacked antennas and arrays are demonstrated to optimise the targeted antenna performances in the smallest footprint possible. These structures meet the requirement for developing inexpensive compact millimeter-wave antennas and antenna systems. Different structures and architectures are theoretically and experimentally studied and discussed for specific space- and ground-based appli-cations. Practical issues such as high-density integration and high-volume manufacturability are also addressed