###### Abstract  
A linear phased array antenna excited with a novel composite right/left-handed (CRLH) phase shifters structure is proposed. The phase of the conventional CRLH transmission line is controlled with magnetically aligned micron-sized particles embedded inside the unit cell of the CRLH transmission line. The cascading of unit cells produces the desired phase shifts for the main beam scanning of the linear antenna array operating at a 5.5 GHz center frequency for Wi-Fi 6 applications. The proposed phase shifter design has a very low insertion loss (0.5-2 dB), excellent matching characteristics with the antenna array (less than \(-\)10 dB) and a small phase error (1-2 degrees). A 1 \(\times\) 4 linear patch antenna phased array operating at a 5.5 GHz center frequency of the Wi-Fi 6 band is simulated using the Method of Moments (MoM) simulator platform. Then, the array is driven with the proposed novel CRLH phase shifters for the main beam at broadside and the main beam steered at 15- and 30-degree scan angles toward the desired users. For experimental validation, multiple unit cells of the proposed phase shifters are fabricated, and the 1 \(\times\) 4 patch antenna array is fed with these fabricated unit cells of the phase shifters. The phased array radiation patterns are measured using an in-house fully calibrated anechoic chamber and were compared with simulated phased array patterns. The measured phased array patterns are in good agreement with the simulated patterns. As compared with commercially available phase shifters, the proposed novel CRLH phase shifters do not need external complex biasing circuitry, which is a major advantage in space constraint limitations at the router side of multi-user MIMO-OFDM systems. m 2023 30 January 2023 3 February 2023 3 February 2023 30 January  
arenas [2; 3]. Beamforming is a technology that allows the antennas in the router or a client device (such as a tablet, smartphone and laptop) to focus information signals toward the intended users and nulls (signals not of interest) toward the interferers. In Wi-Fi 6 and beyond generations, in combination with multi-user MIMO (MU-MIMO) technologies, beamforming helps users obtain more secure connections that boost their data rates. Wi-Fi 6 with MU-MIMO uses multiple spatial data streams for simultaneous communication with multiple devices using array antennas [4; 5; 6]. The Wi-Fi Alliance (WFA) specifications for various Wi-Fi standards are given in Table 1. The spatial stream is the antenna of an access point (router). A large number of antennas indicates higher throughput of the entire system. Array antennas in communication systems are popular because of the ability to electronically scan the directive beam instead of mechanical slewing. The beam pattern is scanned toward the signal of interest (desired user) in angular space by dynamically adjusting the excitation phases. Such an array is referred to as a phased array [7]. The excitation phases in a phased array are achieved with commercially available phase shifters. However, achieving the desired phases with commercially available phase shifters requires external dc biasing circuitry. If the dc control circuitry is designed on the same layer as the phase shifters, then there is a probability of coupling between the RF signal and dc signals. Therefore, dc signals may interfere with the RF signal in the array, which can cause variations in the desired amplitudes and phases of the antenna elements in the array. This can cause a reduction in antenna/array gain, efficiency and possible distortions of the radiation patterns [8; 9]. Another disadvantage of the commercially available phase shifters is their limitations of usage in flexible and conformal electronics applications as they cannot be made flexible/bend due to the discrete electronics components. Currently, active research work is in progress to design and develop flexible antennas, flexible phased array antennas and flexible phase shifters for conforming them on commercial Wi-Fi routers [10; 11].