Investigation on electrically small antennas in the microwave range for the wireless transfer of power

According to Ericsson’s Mobility report of November 2020, it is estimated that mobile subscriptions will increase to 8.8 billion by the end of 2026, of which 91 percent will be for mobile broadband. It is projected that the number of unique mobile subscribers be 6.4 billion by the end of the forecast period. Continuous growth in smartphone penetration and subscriptions associated with smartphones account for about 75 percent of all mobile phone subscriptions. Such a huge growth in demand puts significant pressure on electronic and RF engineers, that need to develop compact, reliable devices in a fast way and at a low cost. Since, every bit of information, every bunch of sensor data is delivered through it, the antenna is a key component to develop a wireless portable device at the same time reliable and compact. In many instances, a conventional external monopole or dipole antenna is not an option, such as in wearable devices, trackers and many other applications cannot afford to feature a prominent element out of the device that can be unintentionally broken. In this document, the fundamental limits on electrically small antennas are studied, where is described the impact of the quality factor in their size, bandwidth, and radiation efficiency. In this document, planar technologies, and “antenna-less” technologies are presented as solutions providers for the proper integration of radiating systems in small wireless portable devices constructed in a way that the radiating system may be properly integrated, ensuring good wireless performance in terms of radiated power, received power sensitivity, and taking in consideration constraints such as the mechanical fit, electrical fit, and assembly fit. In this document, a real-life testing platform is compared and proved by the use of CAD tools, for circuital and EM simulations.