A 1-bit reconfigurable intelligent metasurface-based antenna for 5G application is proposed. The proposed antenna based on artificial electromagnetic metamaterial has the advantages of easy processing and low cost. This meets the requirements of future communication network development. This antenna shows that the unit cell has a stable 180° phase difference between the ON and OFF states by loading a PIN diode at 6.425–7.125 GHz. A 10 × 10 array antenna is constructed by using 2 × 2 meta-atoms to reduce the complexity of the control network. This proposed antenna can achieve ±40° beam scanning with a gain tolerance of 3 dB and a maximum gain of 18.7 dBi. In addition, beamforming performance, such as multi-beams, is also achieved. These properties ensure that the proposed antenna has great potential in wireless communication systems and microwave imaging systems.

In this paper, we propose a novel method for obtaining wideband spectral information of the target in microwave imaging systems by using broadband frequency reconfigurable printed transceivers. The proposed transceiver is composed of two embedded stacked microstrip antenna configurations operating in C-band (5.5–8.5 GHz) and X-band (8.5–11.5 GHz) with each having 3 GHz bandwidth. The transceiver switches between the two configurations (and thus frequency bands) using PIN diodes and collects response of the antenna in the presence of the target, in both the operating bands. This information is then combined to obtain wideband spectral information of the target from 5.5 to 11.5 GHz to achieve improved image reconstruction. The proposed reconfigurable transceiver has advantage over traditional broadband transceivers (those have slots/meandering at ground plane to achieve wideband response) that it has unidirectional radiation patterns throughout its band of operation. Hence the imaging system is implemented without the absorbers. This keeps the system compact and inconspicuous when installed for security applications. Here, a bistatic system is employed with two-dimensional target scanning performed in a real outdoor environment.

The meta-surface is introduced into the design of band-notched monopole antennas with single/dual/triple notched bands around 3.6/5.5/7.2 GHz for ultra-wideband (UWB) communication. We show that strong coupling effects between the meta-surface and the antenna would be created through tuning the orientations of the meta-cells according to the field distributions on the antenna surface, and eventually, filter the unwanted radiations of the antenna. Especially, by simply attaching different meta-surfaces on the back of the antenna, the band-notched properties are shown to be changeable without hurting the original structure of the antenna. Both simulation and measurement results demonstrate the monopole with replaceable meta-surfaces has achieved an UWB operating band ranging from 3 to 9 GHz for voltage standing wave ratio (VSWR) ≤ 2 with single/dual/triple notched bands covering frequencies around 3.6/5.5/7.2 GHz. Such a design would obtain significant notched performances for the desired bands and maintain the good radiations in the operating frequency, which make it a suitable candidate for UWB applications.

An innovative and simple method for attaining broadband frequency reconfigurable antenna structure is presented using low-cost materials and a compact design. The frequency reconfigurability is attained by the “OFF” and “ON” mechanisms of three PIN diodes. Many performance observations are carried out such as reflectance coefficient, bandwidth (BW), resonance frequency, electric field, feed position variation, and gain among different configurations. The suitability of the presented work for the different applications lies in the X frequency band. The resonating frequency for all switch OFF modes is achieved at 13.2 GHz and one switch ON mode at 10.7 GHz. The proposed design yields the frequency tunability behavior over the broadband of 2.5 GHz. The design yields the directivity of 5.58 dB, the minimum reflectance coefficient of −17.27 dB, and a total gain of 3.87 dB. This design offers an electric field of 46 558 v/m, a BW of 340 MHz, and a normalized directivity of 87° using low-cost substrates. The results of the presented design were also fabricated and related to simulated results. Performance observation of the proposed work with previously published research work is also included. The presented design provides the solution of the low-cost, compact, reconfigurable antennas, which can be used for next-generation communication systems.

Cable-driven parallel robots (CDPRs) are still gaining attention thanks to their interesting characteristics compared to serial or classic parallel manipulators. However, the limited range of rotation of their end-effectors reduces their application fields to predominantly translational movements. In this context, the issue of extending the rotational workspace of a CDPR while maintaining a compact robot structure is addressed in this paper. This work is motivated by the need to find the optimal CDPR for upper limb rehabilitation allowing to assist the patient’s hand along a set of prescribed tasks. Firstly, a reconfigurable robot, where the motors’ locations are movable, is proposed in order to help reaching all the prescribed poses. Although this solution presents promising results compared to classical CDPRs, it involves a sizable robot structure inadequate to rehabilitation application. To improve the obtained solution, another approach is proposed, based on combining the large translational workspace of CDPRs and the large rotational workspace of serial manipulators. The optimal structure of a hybrid robot will be considered for the prototype design.

Modules are requisite for the realization of modular reconfigurable manipulators. The design of modules in literature mainly revolves around geometric aspects and features such as lengths, connectivity and adaptivity. Optimizing and designing the modules based on dynamic performance is considered as a challenge here. The present paper introduces an Architecture-Prominent-Sectioning (APS) strategy for the planning of architecture of modules such that a reconfigurable manipulator possesses minimal joint torques during its operations. Proposed here is the transferring of complete structure into an equivalent system, perform optimization and map the resulting arrangement into possible architecture. The strategy has been applied on a set of modular configurations considering three-primitive-paths. The possibility of getting advanced/complex shapes is also discussed to incorporate the idea of a modular library.

In this paper, non-uniform meandered line shunt capacitive RF-MEMS switch is presented at an elliptical patch etched with a split-ring resonator (SRR) for satellite communication applications. The non-uniform meander line shunt capacitive is a fixed-fixed type of RF-MEMS switch that is introduced in this model antenna. The proposed antenna design is resonated at 10.46 GHz with the return loss of −37.6 dB. The performance evolution of the proposed antenna design is evaluated with and without integrated RF-MEMS switch on the proposed antenna SRR. It is observed that the proposed model at the ON-state switch resonates at 10.57 GHz frequency with the return loss of −30 dB. Similarly, at the OFF-state switch, it resonates at 10.53 GHz frequency with the return loss of −43 dB. Al3N4 (aluminum nitride) is used for the switch as a dielectric material, hence the switch attains higher isolation. The actuation voltage of 7.9 V is required for the switch to actuate from ON to OFF state. The switch attains minimum insertion and return loss which is discussed in further sections. The proposed antenna is fabricated and tested by a vector network analyzer; there is a good agreement between the simulated and measured results.

A compact ultrawideband (UWB) antenna with reconfigurable triple band notch characteristics is proposed in this paper. The antenna consists of a coplanar waveguide-fed top-cut circular-shaped radiator with two etched C-shaped slots, a pair of split-ring resonators (SRRs) on the backside and four p-type intrinsic n-type (PIN) diodes integrated in the slots and SRRs. By controlling the current distribution in the slots and SRRs, the antenna can realize eight band notch states with independent switch ability, which allows UWB to coexist with 5G (3.3–4.4 GHz)/WiMAX (3.3–3.6 GHz), WLAN (5.15–5.825 GHz), and X-band (7.9–8.4 GHz) bands without interference. By utilizing a nested structure of C-shaped slots and SRRs on the backside, a compact size of 18 × 19.5 mm2 is achieved along with multimode triple band notch reconfigurability. The antenna covers a bandwidth of 3.1–10.6 GHz. A prototype is fabricated and tested. The simulated and experimental results are in good agreement.

A compact ultra-wideband (UWB) monopole antenna with reconfigurable band-notch characteristics is demonstrated in this paper. It is comprised of a modified rectangular patch and a defected ground plane. The band-notch property in the WiMAX and WLAN bands is achieved by etching an open-ended slot on the radiating patch and an inverted U-shaped slot on the ground plane, respectively. To obtain the reconfigurable band-notch performance, two PIN diodes are inserted in the slots, and then the notch-band can be switched by changing the states of the PIN diodes. The antenna has a compact size of 0.47 λ1 × 0.27 λ1. The simulated and measured results indicate that the antenna can operate at a UWB mode, two single band-notch modes, and a dual band-notch mode. Moreover, stable radiation patterns are obtained.

In this work, a new compact, low profile, frequency, and end-fire pattern reconfigurable antenna is presented. The proposed antenna consists of four parasitic elements and an electric-inductive-capacitive (ELC) resonator enclosed with a closed ring resonator (CRR). The reconfigurability in the proposed antenna is achieved with the help of five PIN diodes (D1–D5) embedded on the top surface of the substrate. The diode (D1) is implanted between ELC and CRR resonators for frequency reconfigurability. The other four diodes (D2–D5) are implanted between the ground plane and four parasitic elements to control the electrical length of the ground plane to achieve pattern diversity. The ground plane and parasitic elements steer the primary omni-directional beam to bi-directional and uni-directional end-fire radiation at multiple frequencies. The proposed antenna exhibits multiband operation and end-fire pattern diversity depending upon the different states of PIN diodes. The overall size of the proposed antenna is 0.20λ0× 0.17λ0× 0.009λ0, where λ0 is calculated at the lowest resonance frequency. The impedance bandwidth of the antenna ranges from 1.45 to 26.22%, while peak gain varies from 0.86 to 3.86 dBi depending upon the state of operation. The measured results are in agreement with the simulated results, which confirm the frequency and pattern diversity performance of the antenna. The proposed antenna can be used in back-to-back repeater systems.

A low specific absorption rate (SAR) reconfigurable multiband coplanar waveguide fed planar inverted-F antenna (PIFA) is presented in this paper. Different numbers of meander-turn-shaped slots are etched on the PIFA radiating plate to excite new resonant frequencies. Extra resonant frequencies are created by increasing the number of meander-turn-shaped slots for different wireless communication applications. A new independent resonant frequency is created by etching a coupled slot within the ground plane for the upper WLAN. A PIN diode switch is used to reconfigure the fundamental resonant frequency from the LTE band 11 to band 8 with a total of 63% size reduction compared with the original PIFA size. Furthermore, the SAR in the human head is investigated using the Hugo voxel model in CST Microwave Studio. The volume of the antenna is 22 × 30 mm2 over a 35 × 50 mm2 ground plane, which is suitable for handheld devices.