## 1 Introduction
The U-NII (Unlicensed National Information Infrastructure) radio band [32], which was established by the United Federal Communications Commission, is part of the microwave frequency spectrum from 5.150 to 7.125 GHz. This frequency band is used by WLAN devices and wireless ISPs. Wireless ISPs generally use a 5.825-7.725 GHz band span. In March 2021, U-NII provided a total of eight ranges, which were segmented as U-NII-1-U-NII-8. U-NII-1 to U-NII-4 ranges are for 5 GHz WLAN, which are 802.11 a and later standards; U-NII-5 to U-NII-8 areas are for 6 GHz WLAN, which are 802.11 ax standards; UNII-2 is divided into three sub-range sections through A to C. Licensed amateur radio operators are authorized to use 5.650-5.925 in the USA. Due to a shared IEEE standard, many countries use similar bands for wireless communication. The European HiperLAN standard operates in the same frequency band as the U-NII. The U-NII-1, U-NII-2A, and U-NII-3 bands are also used for Wi-Fi as well, being used both indoors and outdoors for higher bandwidth capacity. The concept of dual-band Wi-Fi comes from the need for extra data capacity and coverage; the dual-band architecture of 2.4 GHz and 5.6 GHz bands in gateways and end notes have become the most popular. The users are allowed to connect more devices to the Internet using the 5 GHz spectrum in a more effective way when a home mesh system with several routers is used to cover a bigger area; the UNII band 5.6 GHz can be worked as a dedicated communications connection between the two routers, speeding up the overall system using a dual-band [33] configuration. In this study, two SRR-constrained double C-shaped metamaterials are presented for S, C, and X band applications. The proposed design provides a unique shape with a miniaturized size: a dimension of 0.0156\(\lambda\)\(\times\) 0.0156\(\lambda\). The proposed metamaterial produced quadruple resonance covering for Wi-Fi and satellite communication applications. Moreover, it can provide a wider bandwidth of 1.65 GHz at 11.5 GHz. The developed double C-shaped left-handed metamaterial exhibited a highly effective medium ratio (EMR) of 15.6 that showed compactness, which is relatively high in this regard compared to the recently proposed metamaterials. The S band is very popular with a 2.4 GHz resonance frequency for Wi-Fi and other applications such as mobile services, satellite communications, and optical communications. The C band with 5.6 GHz resonance frequency can be used for dual-band Wi-Fi communication along with the 2.4 GHz. It is also applicable in WLAN/WiMAX and radar applications with its large bandwidth of 600 MHz. The other two resonance frequencies, 8.93 GHz and 11.5 GHz are also highly applicable for long-distance communication devices. The 11.5 GHz under the X band has a high bandwidth of 1650 MHz, which can be employed in long-distance satellite communication applications. Metamaterials are presently a prominent focus of study to build lightweight, small, and low-cost devices for improving radar and satellite application functionality. The proposed unit cell was developed with the high-performance Rogers RT5990 substrate and the design is achieved with an EMR of 15.6, which is better than the existing works. Moreover, the demonstration is observed with the suggested design's compactness and effectiveness. The CST studio suite 2019 and the finite integration technique (FIT) were used to design and analyze the considered metamaterial properties that are broadly described in this manuscript.