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Publisher Copyright: © 1963-2012 IEEE. Integrated lens antennas are widely used in high gain and beam steering applications at millimeter-wave frequencies. The ILA has often large height and suffers from significant scan loss. In this article, we demonstrate a low-profile, efficient, and scanloss-reduced integrated metal-lens antenna (IMLA). An IMLA is a combination of a dielectric lens and metal-plate lens. A 16-λ 0 diameter IMLA is designed using the HDPE and 58 stainless steel plates to achieve the f/d of 0.69. The simulated aperture and radiation efficiency of the IMLA are 73% and 92%, respectively. At 76 GHz, the simulated and measured realized gains of the fabricated IMLA are 31.24 and 31 dBi, respectively. The IMLA is designed to steer the main beam to ±30°. The scan loss is reduced by tilting the radiation pattern of the feeds at offset positions along the focal plane. The radiation pattern of the square waveguide feed is tilted using asymmetrical dielectric pins. The asymmetrical dielectric pins reduce the simulated gain scan loss of the IMLA by more than 1.5 dB at 30° steering angle. The simulation results show that the inclination of the feed radiation pattern helps limit the scan loss of the IMLA to 4.1 and 4.3 dB in the H-and E-planes for 30° steering angle, respectively. The measured scan loss of the manufactured IMLA is 3.8 and 6.2 dB in the H-and E-plane, respectively.

In this article, the design of a radiation beam-reconfigurable antenna using the reflector pins is presented. The reflector pins make a short or open connection with the ground, via switches and Plated Through Hole (PTH), which helps in controlling radiation characteristics of the proposed antenna. This design contains a simple 3D printed Cylindrical Dielectric Resonator Antenna that is located at the center of the substrate. The beam-sweeping of the antenna is attained by operating switches in different combinations of ON and OFF states. The reconfigurable CDRA operates at 4.5 GHz and covers all azimuth angles in four steps with a maximum measured gain of 6.6 dBi. This beam-switching antenna is very advantageous because of its trait of eliminating fade zones and beamforming.

International audience; We present a photonically-excited antenna array at E-band for scanning by beam switching in wireless links. First, we discuss the proposed technique applied to photonic-enabled (sub)millimeter-wave transmitters. Next, we present the proposed solution; it consists of two sub-arrays of stacked patches as primary feeds of a Polytetrafluoroethylene (PTFE) lens, with one photodiode feeding each sub-array. To validate the assembly, the return loss and radiation patterns have been measured for one of the sub-arrays excited with a coplanar probe. In turn, the lens illuminated by one of the sub-arrays yields a directivity of 27 dBi. The radiation patterns measured for the transmitter module (including the lens) are in very good agreement with full-wave simulations, and they show that excitation of one of either sub-arrays allows beam switching between 2.7 with a beam crossover at 3 dB. Finally, we have tested the transmitter in a 0.6 m wireless link. Depending on the position of the detector and on which subarray is excited, we have accomplished 5 Gbps transmission for on-off-keying modulation and direct detection (BER = 1E11). The system constitutes an initial proof of photonic-assisted beam switching for mm-wave transmitters enabling broadband operation with a directive and switchable beam. IEEE

Satellites are currently the most effective means to achieve seamless global coverage of the Internet. Due to the frequent beam switching caused by the high-speed movement of satellites, it is too expensive to directly apply the location management strategy in the terrestrial network to the satellite Internet constellation (SIC). To build a web browsing platform based on satellite Internet, it is necessary to display the location of satellites and terminals in real time. For this reason, this paper proposes the location management strategy of SIC. It uses the characteristics of large and periodic satellite beam coverage in a certain period of time, redesigns the location management database structure, location registration mechanism and call delivery mechanism, and analyses and simulates the bit cost of location management. The result proves that compared with the traditional strategy, this strategy greatly reduces the cost of SIC.

A novel fixed-frequency beam switchable dual-beam antenna array is presented, which consists five dual-beam leaky-wave antenna (LWA) elements designed on substrate integrated waveguide (SIW) and integrated together on a common substrate. The LWAs work on fundamental wave and -1th spatial harmonic wave simultaneously and excite two symmetrical radiation beams in forward and backward direction respectively. In order to realize beam switching, three voltage-driven radio frequency chip switches (CSW-RFs) are used and integrated behind the antenna aperture. Since the periodic slot in LWA causes open stopband at the operating frequency, so the staggered radius amplification of local vias in the via walls of SIW is performed to suppress the open stopband. In addition, electromagnetic band-gap (EBG) structures, capable of reducing coupling between neighboring antenna elements, are embedded in between LWAs. The proposed dual-beam antenna array with beam switching capability between ±35, ±45, ±55, ±65 and ±75 degrees at 28 GHz are simulated, fabricated and measured. Both analysis and measurement results show that the proposed antenna array exhibits an excellent performance, which can be used in fixed-frequency beam-switching millimeter wave communication.

IEEE open journal of antennas and propagation 1, 2-10 (2020). doi:10.1109/OJAP.2019.2955507, Published by IEEE, [New York, NY]

A study of multiple-ion therapy with charged heavy-ion beams was performed to improve outcomes of refractory cancer treatments. We proposed the accelerator operation method for applying the multiple-ion therapy, to quickly switch the ion species and energies of the output beams. In this method, the irradiation ion species can be changed only by switching the selected ion source and the injector parameters, and the output beam energies can be varied without changing the magnetic operation patterns of the synchrotron. We verified the effectiveness of our approach by conducting experiments at the Heavy Ion Medical Accelerator in Chiba (HIMAC) and confirmed that the approach can provide the fast switching of both the ion species and the beam energies. The experimental results also demonstrated that our approach will greatly reduce the commissioning time and the routine adjustments for multiple-ion beams.

In the low earth orbit satellite network, since the running speed of low earth orbit satellites is much higher than the average speed of mobile users, users frequently switch. It is necessary to solve the problem of how to find the best switching satellite and how to effectively use the limited channels, so as to improve the service quality of users. In this paper, the current situation of switching strategies in satellite networks is analyzed, and the applicability of existing beam switching strategies and inter-satellite switching strategies for channel allocation and how to find the best switching target satellite in satellite-ground integrated networks is explored. The development and challenges of switching strategies in LEO satellite networks are also analyzed.

Conférence virtuelle; International audience; We present a photonic transmitter at E-band for beam switching in mm-wave wireless links. First, we discuss the trade-offs between beam switching and beam steering with arrays of photonic transmitters. Then, the designed transmitter is presented; it includes two 2×2 sub-arrays of stacked patches fed independently by two photodiodes. The transmitter is placed at the focal plane of a PTFE lens to increase the overall gain. Excitation of either sub-array allows 1D beam witching between ±2.7º for accurate beam alignment or reconfigurable links.

International audience; This abstract describes the first design and assembly of a photonically-excited antenna at E-band for beam switching in millimeter-wave wireless links. The designed antenna consists of two arrays of stacked patches, with one photodiode feeding each array. The stacked patch provides an impedance bandwidth larger than 23 % and a stable radiation pattern over the E-band. The array is combined with a lens to increase the overall gain. Excitation of either patch array allows beam steering between ±2.7° for accurate beam alignment. © 2020 IEEE.

This paper presents a MIMO antenna for 5G mm-wave applications. The proposed MIMO is capable of providing continues beam cover in the elevation for up to ± 30° without using phase shifters. The proposed MIMO is fabricated using 3D printing and it has good measured performance over wide band. The proposed MIMO operates at 28 GHz 5G band with a measured bandwidth of more than 4 GHz and a measured peak gain of higher than 10 dBi.

Beam coverage switching of sub-6 GHz massive MIMO antenna is presented using low-loss passive phase shifter. A single-bit phase shifter which minimizes the loss caused by series resistance of a switch is designed and integrated with antenna. The massive MIMO array is fabricated and measured to examine beam switching function while maintaining low-loss characteristics.

In this paper, we propose a reconfigurable metasurface antenna for beam switching applications. The reconfigurable metasurface is formed by uniformly distributed double-split square rings loaded with positive-intrinsic-negative (PIN) diodes for dual operations of a wave reflector and a wave director. Specifically, when the PIN diodes are forward biased, an epsilon-negative (ENG) metasurface is realized which reflects all incident waves with appropriate polarization; when the diodes are reverse biased, at the same operating frequency, a mu-near-zero (MNZ) metasurface is acquired which directs wave propagation. For excitation, a dipole radiator loaded with the same type of PIN diode is designed. Simulation and measurement results show good agreement and verify the beam switching functionality of the proposed metasurface antenna.

Power dividers are critical components for mm-wave applications. They are used in antenna feeding structures to provide the suitable excitation in the antenna array systems and deployed in microwave smart beam switching subsystems. In this article a dual gap wideband in-phase power divider is presented. The bandwidth starts at 19 and ends at 40 GHz. We are targeting with this design both the k and ka bands. The proposed design achieved a very deep matching level below −18 dB.

A wideband pattern-reconfigurable cone antenna employing liquid-metal reflectors is presented. The proposed pattern-reconfigurable antenna consists of a metal cone as the main radiators and eight poles as reflectors for beam switching. It is simple in design and has a wide impedance bandwidth. By changing the states of poles, beam steering can be achieved, where the effect of reflection mechanism is theoretically researched and experimentally validated. Simulated and measured results are found in good agreement with each other. A prototype antenna with four radiation modes is fabricated, which can perform 21 kinds of beam steering over a 360° coverage. It has a fractional bandwidth of 45.5% covering from 1.7 to 2.7 GHz.

For modern directional communication networks, there is a significant and growing need for advanced antenna array designs that combine the high gain and broadband performance together with the low-cost and lightweight characteristics. In this letter, the beam-switching characteristics of a new 4 × 8 right-hand circularly polarized long slot antenna (LSA) array were analyzed when fed by an 8 × 8 Butler matrix. The radiation characteristics were analyzed in terms of bandwidth, beamwidth, gain, cross polarization (x-pol), and axial ratio. Stable radiation patterns were obtained when the main beam directions were within the ±30° angle. The beam-switching LSA array has measured gain of 13.5 dBic and beamwidth of 15° with x-pol greater than 10 dB and axial ratio less than 6 dB. Comparative results with a 4 × 8 stacked patch antenna array are also included for reference.

Dynamic steering of laser beams by ultrathin optical metasurfaces is a significant research advance for possible applications in remote ranging and sensing. A unique platform for such important functionalities is offered by dielectric metasurfaces that have the highest transmission efficiency. However, the realization of dynamically tunable metasurfaces still remains a challenge. Here we experimentally demonstrate the dynamic switching of beam deflection by a silicon-nanodisk dielectric metasurface infiltrated with liquid crystals. In particular, we show the switching of a laser beam from 0° to a 12° angle with an efficiency of 50% by heating the metasurface to modify the liquid crystal state from nematic to isotropic. Our results open important opportunities for tunable ultrathin beam steering metadevices.

A wideband tapered slot antenna (TSA) with three radiating elements for beam switching purpose is proposed in this study. The integrated radiating taper slots in assistance with metal strips acting as switches provided the proposed design with the capability of switching its beam into three different directions while maintaining the antenna performance stable. To validate the accuracy of the proposed design, the prototype was fabricated and measurements were conducted in terms of reflection coefficient (S11), radiation pattern and realized gain towards the three different operating modes. By sequentially, activating the switches, the antenna main beam rotated 90º in the XY coordinates. A realized gain ranging from 4.3 to 6.4 dBi and a wide operating bandwidth (|S11| ≤-10dB) from 3.3 GHz to 5 GHz were observed throughout the antenna performance in simulation as well as in experiment. With the covered bands, the proposed antenna can be suitable for Sub -6GHz wireless communications systems. Improvements of Trapezoid Antenna Gain using Artificial Magnetic Conductor and Frequency Selective Surface.

An oscillating active integrated antenna (AIA) with a switchable pattern among sum or difference is reported here. The AIA design consists of a passive feedback network and an active device. A two‐port, two‐element patch array coupled electromagnetically through T‐shaped microstrip lines is integrated into the feedback path of the oscillator circuit. This two‐port network acts as a radiator and frequency‐selective network for the oscillator circuit. The proposed AIA can switch in two different radiation pattern states by using p‐i‐n diodes. In the difference pattern, oscillating AIA has a measured null depth of −19.86 dB from the peak. The measured phase noise for both patterns is better than −105.1 dBc/Hz at a 1‐MHz offset from the oscillation frequencies. The dc‐to‐RF efficiencies for both pattern states are better than 20%. The proposed design is suitable to cover the space in a more efficient manner by generating the pattern among broadside or conical.

mm-Wave radars are widely used in the automotive industry, but the concept is rather new for wearable applications, such as detection of obstacles for visually impaired people. Beam-switching techniques for radar antennas, typically, are either complicated or bulky, whereas for wearable applications, simpler methods are desirable. In this paper, we present a high gain antenna array with a low profile and a simple beam-switching design. The concepts of parasitic antenna array and partially reflective surface have been combined to simultaneously achieve a narrow beam (higher gain) as well as beam-switching. Additive manufacturing (screen printing) has been utilized which ensures flexibility (essential for wearable applications) and a lower cost. A ±30° beam switching and 11-13 dB realized gain has been achieved, which is deemed suitable for the given application.

In this work, we propose a circularly polarized (CP) beam-switching wireless power transfer system for ambient energy harvesting applications operating at 2.4 GHz. Beam-switching is achieved using a low profile, electrically small CP antenna array with four elements and a novel miniaturized 4×4 butler matrix. The CP antenna is designed with an e-shaped slot and four antennas. The CP antenna measures 0.32 λ ₀ ×0.32 λ ₀ ×0.006 λ ₀ at 2.4 GHz. The antenna has a gain of 3 dBic and an axial ratio less than 3-dB at 2.4 GHz. A linear antenna array consisting of four elements is designed with the CP antenna element with an inter-element distance of 0.29 λ ₀. A 4×4 butler matrix with miniaturized couplers and crossovers are used to feed the four antenna array elements. Based on the input port of excitation, the main beam of the antenna array is demonstrated to be switched to four directions: −5°, 65°, −55°, and 20°. A CP rectenna is used to demonstrate the wireless power transfer capability of the combination of the butler matrix and the CP-antenna array. The rectenna consists of a Teo-shaped CP antenna and a rectifier. The open circuit voltage at the output of the rectenna is found to peak value of 30 mV at −3°, 61°, −53°, and 17°. Thus a complete system for CP wireless power transfer including the power transmission system as well as the RF energy harvesting sensor is designed and experimentally verified.

The basic objective of AESA seeker is to provide hit to kill performance in air defence scenarios against highly maneuvering targets. The use of AESA seekers for missile terminal phase guidance allows to have the benefits of fastest beam switching towards maneuvering targets. Since AESA seeker is mounted onboard missile, seeker beam has to be stabilized against missile body disturbance to decouple body disturbance from LOS(Line Of Sight) rate. In this paper, concept of AESA beam control and stabilization have been described along with hardware (Gyroscope) in loop simulation results.

A quad port antenna configuration with four antipodal vivaldi radiating elements is presented in this paper. The proposed Multiple Input Multiple Output (MIMO) antenna consists of multiple switches and no parasitic elements like directors or reflectors, to exhibit beam switching and pattern reconfiguration. The absence of these elements reduces the design complexity. The radiation of the proposed antenna can be switched along +y, -x, -y and +x directions, if the antenna is placed in xy- plane. The proposed antenna operates over Ultra Wide Band (UWB) band of 3.1GHz to 10.6GHz making it as a promising choice for futuristic applications like Internet of Things (IoT).

This paper presents the measured results of a $64\mathrm{x}64-$ -way one-body two-dimensional beam-switching Butler matrix using hollow waveguide structure at 19.55 GHz. The one-body two-dimensional switching matrix is realized by introducing the waveguide short-slot 2-plane couplers as hybrid and cross junctions. The 64 beams can cover 39.5% hemisphere by 0.65-wavelength aperture spacing in simulation. The measured beam coverage is almost the same to the simulated one.

We report on a public field trial demonstrating seamless handover in a multi Radio Access Technology mobile network supporting WiFi, LTE, and new 5G radio access in the 60 GHz band for full-duplex enhanced mobile broadband and 5G broadcast hotspots.

Herein, millimeter-wave radar systems for helicopter all-around obstacle detection are proposed. These systems detect and avoid obstacles to ensure flight safety. First, the configuration of a 24 GHz quasi-millimeter-wave radar module is presented. Second, the development of an all-around obstacle detection system with such radar modules is described. Then, the experiments using the all-around obstacle detection system and the multicopter are conducted to examine the fundamental performance of the developed system.

This article presents a novel beam switching antenna design for Small Cell applications. The proposed antenna comprises five dual-polarized dipole antenna sets, two RF switching circuit boards and one hardware control circuit board. The proposed antenna can provide wide operating band covering the 2300–2700 MHz band, and has 31 radiation pattern combinations at +45/−45° polarization individually and has dual RF ports to support 2 × 2 MIMO system. This antenna has a low profile of 76 mm, and the whole size is 200 × 200 × 76 mm3 that can easily mount on indoor ceiling.

A waveguide short-slot two-plane coupler is proposed as a component of 2-D beam-switching Butler matrix. The hybrid and cross coupler operations are designed by including the 2-D polarity symmetry, the propagation constant, and the coupling with the ports of the modes in the coupled region. Their designs are confirmed by experiments. The achieved bandwidth is approximately 2%, restricted by the frequency characteristic of the modes in the coupled region. Since the short-slot two-plane hybrid coupler itself acts as the 2 $\times$ 2-way 2-D beam-switching Butler matrix, the beam switching is also verified by measurements. The general configuration of the 2-D beam-switching Butler matrix is also proposed by using the short-slot two-plane couplers.

The fifth generation (5G) wireless communications systems have brought a growing need for various antennas, electrically small and large, low-gain and large-gain, also at millimeter wavelengths, and in many cases with beam steering or switching capability. Frequencies of 28 GHz, 38 GHz, 58 GHz, 60 GHz, 71–86 GHz, 140–150 GHz, and some even higher window frequencies are of interest in 5G and subsequent generations. Different parts of the systems need different kinds of antennas. In this presentation, we discuss two antenna types that we have recently studied, namely high-gain lenses with beam switching capability and lower gain printed antennas that suit very well for mass production.

We report on novel approach to switch the optical beam profile in a fibre laser using a short piece of special passive fibre. The switching mechanism relies on selective wavelength resonance between the core and a high index surrounding ring in the fibre. Beam switching at 530 kHz from a Gaussian beam shape to a flat-top beam with a ring with corresponding M2 from 1.4 to 3.5 is demonstrated in a modified industrial pulsed fibre laser.

This paper presents design and development of High Power RF SP9T switch at L-Band for data link application. The design can withstand full reverse power under fault conditions. SP9T configuration is achieved through a two stage combination of SP3T switches. The design uses PIN diodes in tuned shunt configuration, one in 1st stage and two in 2nd stage to achieve high isolation. Shunt diode configuration along with λ/4 section of transmission line provides low Insertion Loss (IL).Design challenges and implementation schemes have been discussed. The Maximum insertion loss measured was 1.2 dB and isolation of 53 dB over the band of operation. Simulation and measured results are in good agreement. The switch is used in Electronic beam switching antenna for data link communication.

This paper presents a design of switched beam antenna using parasitic elements for back lobe reduction to reduce interference signals coming from back side. A single circular patch is used to switch main beam pattern. Beam switching is controlled by shorted and open circuit at the edges of the patch while back lobe is reduced by shorted and open circuit at the parasitic elements. There are eight difference directions of beam switching. The maximum gain of the proposed antenna is 7.62 dBi and maximum back lobe reduction is 4.28 dB when parasitic elements are used.

More than half of the mobile backhaul connections are wireless and huge capacity promise of mmW bands is compelling to cope with the increasing data capacity for future 5G system. We reported a backhaul E-band measurement campaign focusing on radio system measurements with the demonstrator developed in the project. The evaluations include the throughput measurement with different modulation coding scheme and hop length in LOS scenario and the link performance in the light obstructed LOS. It is reported that 1 Gbit/s could be supported up to 300 m, and a reliable transmission was possible up to 400 m at the minimum throughput. The accuracy of beam alignment has been evaluated and it could be improved with the help of electrical beam switching function.

In the machine to machine (M2M) propagation environment, beam direction changing technique for small antenna like dipole antenna size is required. We proposed to adopt meta-surface to achieve this instead of reflectarray. However, study of beam switching for meta-surface is not enough despite of important for mobile M2M. To address the issue, this paper proposes novel reflected beam switching method using meta-surface loaded with active elements.

A high-gain beam switching antenna based on frequency selective surfaces (FSS) operating at 5.2 GHz is presented. In this design, a monopole is used as radiating source and surrounded by four columns of FSS screens and four metallic sheets. The FSS unit cell comprises two metallic crosses and a pin diode embedded between them. The transmission characteristics of the FSS unit cell are investigated when the state of the pin diode is ON and OFF. By changing the states of the pin diodes in the FSS screens, beam switching can be achieved at 5.2 GHz. The metallic sheets are used to improve the gain of the antenna. Simulation results show the gain of the beam switching antenna with metallic sheets has been enhanced 7.2 dB compared to that without metallic sheets.