In this paper, a procedure is proposed to design a wideband transmitarray upon a specified frequency band. In this way, the phase control parameter of a unit cell is adjusted in a suggested range, ensuring linear phase change and low transmission loss over the band. The unit cell is designed for a range of phase control parameters (e.g., slot length in a CSRR), in which a 360° phase variation is provided. Part of this range is applied for the central elements of TA, in which the maximum overlapped passband (for different values of phase control parameter) around the desired frequency is to be achieved. In this way, a scenario for the phase specification of the array elements would be obtained. This range is specially applied for the central elements of the array, which are in exposure to feed peak power. As a proof of this concept, a 14×14 element transmitarray is designed and fabricated based on a back-to[1]back square Complementary Split-Ring Resonator (CSRR). Measurement results indicate maximum gain, 1-dB bandwidth, and aperture efficiency of 24.6 dB, 18.4%, and 53% respectively, at the center frequency of 11.5GHz. At the end of the paper, a comparison between the proposed TA and the previous ones is provided.

A reflectarray optimized through a Generative Adversarial Network (GAN) is demonstrated. This design focuses on the impact of the top layer on the reflection phase and utilizes the correlation between phase distribution and the direction of the reflected beam. Six programmable subcells are optimized to accommodate two incident angle waves simultaneously. Silicon substrate is exploited making the design compatible with integrated circuits. The far-field analysis indicates that for incident angles of 19.471° and 41.81°, as well as their vicinity, the reflectarray effectively redirects the incoming waves to reflect towards near-normal direction to its surface. This suggests a near independence of the deflection angle from the incident angle within a specific angular range, making the proposed reflectarray a planar THz beam collimator. The proposed subcells achieve a reflection phase range of 342°. The return losses for the incident angles of 19.471° and 41.81° are 1.9 dB and 1.4 dB, respectively. For a finite reflectarray measuring 15λ×5λ, the pattern gain and fractional bandwidth are reported as 19.44 dB and 24.8% for the incident angle of 19.471°, and 19.17 dB and 29.9% for the incident angle of 41.81°. This denotes an excellent wideband behavior for the proposed single-layer pixelated reflectarray.

This paper presents a new design of microwave microelectromechanical systems (MEMS) phase shifter for dual band wireless local area network (WLAN) applications. A bit is designed which produce a constant phase shift of 11.25o by switching between two lines that consist of 12 and 6 Unitcells in each frequency band. A Unitcell is constructed by gold membrane suspended over the coplanar waveguide (CPW) that can be moved vertically by electrostatic actuation. It can also ultimately be used for changing the operating frequency band. Two states of Unitcell are used to switch between two frequency bands of 2.4 GHz and 5.2 GHz (IEEE 802.11 standard employed in dual band WLAN systems). First, a closed form equation of simplified model of the structure is obtained. Then, using this equation and advanced design system (ADS) simulator, the dual band phase shifter is designed. The validation of modeling and equations are demonstrated using the High Frequency Structure Simulator (HFSS). At the frequency of 2.4 GHz, maximum return and insertion losses are -16.96 and -0.12 dB, respectively that exhibit a phase shift efficiency of 93.75o/dB (60.22o/cm). At the frequency of 5.2 GHz, maximum return and insertion loss are -16.86 and -0.15 dB, respectively exhibiting a phase shift efficiency of 75o/dB (60.22o/cm). The new proposed design is only to achieve a dual band phase shifter using MEMS technology which has low loss and weight with high linearity respect to the other technologies.

In this paper, new topology of phase shifter is proposed that uses advantage of metamaterial and MEMS technology. The phase shifter is switched between two states of RH-and LH-TL having frequency passband unlike other proposed metamaterials which create the maximum phase shift from one Unitcell. Analysis and design approach of the phase shifter is presented and the structure is simulated using 3D simulator. The phase shifter creates 180 degree phase shift with return loss and insertion loss that are better than 15 dB and 0. 25 dB in both states at frequency ranges of 1. 4-4. 4 GHz. Therefore, low loss, high bandwidth and high phase shift are the advantages of the new proposed phase shifter.