## 3 Design Procedure  
The design of a wearable textile antenna that utilizes clothing components can be quite challenging and, to some extent, more complex compared to the design of a conventional textile antenna. The design challenges are mainly linked to the material properties of the applied CC, the detailed and complex CC geometry that needs to be taken into consideration, and the concept of applying a CC. In this section, an effective step-by-step design procedure for textile CC antennas is recorded, reviewed, and analytically described. The recorded five steps are derived through research works presented in the literature and conducted by the authors of this paper. The five steps of the design procedure are listed below:  
1. Concept selection
2. Materials definition and characterization
3. Reference antenna design
4. CC antenna initial design and modeling
5. Final CC antenna validation  
The main target of this analysis is to give an insight into the design procedure, specific challenges from an engineering point of view, and difficulties with the processes followed in each step. Emphasis is given to the special nature and design prediction of CC when employed in or as WTA. Each design step is described through examples, simulations, and measurements. 1. Concept Selection  
The primary fundamental step in the design procedure of a CC textile antenna is the concept selection. This design step deals with the determination of the antenna application type and the involved requirements and specifications. Regarding the application type, a CC textile antenna can provide the wireless connectivity within the framework of healthcare monitoring, specialized occupations (e.g., firefighters and rescue services) surveillance, or sports and fitness recording, for instance. Subsequently, the wireless communication technology that can support the desired application needs to be designated. Wireless PersonalArea Networks (WPAN) (e.g., Bluetooth), WLAN (e.g., Wi-Fi), or cellular (e.g., GSM, 5G) wireless standards can be implemented to establish the communication link. Furthermore, the on-body environment in which wearable antennas operate imposes requirements that should be included in the antenna's design criteria. The wearable antenna should be lightweight, low profile, and, present compactness and flexibility provided by the textile materials and clothing components to be specified. In this design step, the antenna frequency of operation can be assigned (e.g., 1.9 GHz, 2.4 GHz, 5 GHz) based on the selected wireless communication standard. Additionally, the wearable operation mode should be clarified to enable wireless on- and off-body communication links. All these considerations can lead to defining the type of antenna to be designed (e.g., a monopole antenna, microstrip antenna, or planar inverted F-antenna). For example, if an on-body wearable operation mode is required with an operating frequency of 2.4 GHz, then, a vertical top-loaded monopole could be a suitable candidate and could be designed by using a button configuration, as presented in Section 2. Further, in this step, and depending on the above considerations, we should determine if the CC can serve as the main radiator or if it will be part of the antenna. This first step will result in a basic scribble of our antenna to be designed. To establish this design step, a realized published example [53] is visualized in Figure 5.  
To summarize step (a), the concept selection is described in short as follows: (i) application, (ii) wireless technology, (iii) frequency of operation, (iv) operation mode (on-/off-body link), (v) type of antenna, and (vi) usage of CC (as part of the antenna/or as the main radiator). (b) Materials definition and characterization  
Generally, fabric materials and components that are widely used and easily accessed are potential candidates to apply within the textile antenna design. Still, the material selection is crucial regarding the textile antenna performance [7].