# A Review of Multifunctional Antenna Designs for Internet of Things
## 2 Materials and Methods
### Smart Cities
#### 2.3.3 Necessity of Integrated Social-Technical Systems--Smart Cities  
The properties of the presented antennas are summarized in Table 3. In the literature, two major methodologies for designing antenna arrays are proposed: designing only the phased array or designing the array with the beamforming/feeding network. In the first approach [56; 103; 110], the design techniques are presented along with results such as angle  
Figure 19: (**a**) Schematic and (**b**) fabricated all-polarization \(\Gamma\)-dipole array [56]. Figure 20: (**a**) Top view of multi-sectoral annular antenna: (**b**) measured S-parameters and (**c**) beam-steering capabilities [110]. coverage, polarization, and gain. The beam coverage is then estimated by feeding each port with the appropriate phase-shifted current. This technique saves researchers a lot of trouble, as they only need to devise a design plan for the antenna, leaving the feeding network for a future phase. However, this methodology is impractical for real-life applications, where the realization of smart cities demands all-in-one wireless systems capable of being integrated into each IoT device. These elements need to incorporate both the antenna and an electronically reconfigurable feeding network (controlled by a microprocessor or microcontroller) capable of steering the main lobe and enabling space-division multiple access (SDMA). The biggest challenge in this direction is the electronically tunable feeding network and its integration with the microcontroller. In most cases in the literature, due to the limitation of tunable components, only a finite number of desirable beams (states) can be issued to cover all the space [9]. Despite these efforts, in the future, the next-generation of the IoT will demand versatile antenna systems, permitting a main lobe scanning along every azimuth and elevation angle in real time. Following this path, adaptive continuous beamforming networks have emerged, targeting full control of currents' amplitude and phase [111; 112; 113; 114]. Despite these efforts, such networks generally have a small number of ports (\(N=4\)). Therefore, there is still a long way to go and there is a need for fully adaptive beamforming networks for large phased arrays to pave the way for establishing cognitive radio. Despite significant efforts to develop smart city technologies, there remains a lack of essential dialogue between all stakeholders, including the citizens themselves. Although the concept of a \"smart\" city is widely discussed, many cities still fail to utilize available technologies effectively, leaving them \"dumb\" in aspects such as street lighting and wireless metering. What is missing is an integrated systems approach that ensures fairness and equity for all stakeholders through open dialogue. A promising initiative could begin with local universities taking the lead in addressing city officials and councils, while actively involving citizen organizations. This collaborative platform would allow citizens to voice their requests, while university engineers propose technical solutions that can be modified for implementation by municipal authorities. Additionally, ideas for addressing the economic and financial dimensions of smart city projects, such as crowdfunding or projecting future cost savings to benefit citizens, could be presented and discussed by the forum. Engineers play a crucial role in the development of novel, low-cost, and highly efficient integrated electronic systems, where the RF front end, antennas, and digital processing units are implemented on the same chip (system on a chip). These compact systems need to be deployable in various parts of the city, such as traffic lights, rooftops, and electric poles, to provide seamless wireless communication between different IoT devices, ensuring the convenience and safety of citizens. An important lesson from wired digital communications (DSL, ADSL, and VOIP) is that their success lies in backward compatibility, meaning they all build upon the same infrastructure (copper lines).