## 1 Introduction
The design of the upper set of coils, the receiver, is known as \"DDQ\", named after its geometric arrangement, which consists of two \"D\"-shaped coils positioned side by side (DD) and a third coil placed above them (Q). This configuration follows the same principles for collecting magnetic flux lines as observed in other works that utilize similar designs [10; 11; 12; 13]. All three coils are positioned horizontally (i.e., the coil plane is parallel to the road), with a ferrite plate situated above the coils. Ferrite serves to divert the magnetic flux lines and increase the total magnetic flux lines that cross the coils. It is also uses as a magnetic screen, as it significantly reduces the magnetic flux above it, at the EV floor height. Figure 2 displays the magnetic field intensity distribution generated by the transmitter coils. These coils (shown in the bottom part of Figures 1 and 2) are connected in series in a bi-polar orientation. Therefore, the flux lines generated in one polarity in one coil are closed in reversed polarity through the other. As seen in Figure 2, the flux lines arrive at the receiving coils' height at a low angle, and the ferrite deflects them to increase the angle. As a result, an increased electromagnetic coupling coefficient between the transmitter and receiver coils is achieved, increasing energy transfer efficiency to about 80% [14]. However, a larger angle seems desirable for further efficiency improvement. Therefore, the goal of the present work is to suggest a new coil configuration to achieve even higher efficiency levels. To achieve this, we propose a configuration which we name \"Vertical Coils\" (VCs). As displayed in Figure 3, multiple receiving coils are wound around a ferrite core, making the ferrite the central element. Since the ferrite concentrates the magnetic flux lines therein and orients them in an angle close to perpendicular to the receiver coils, we prove that this new configuration results in higher voltage output and increased overall efficiency. The idea of rotating the receiver coil plane, from near parallel to near vertical to the flux line direction, seems trivial for improving voltage pickup and energy transfer. The main reason why such a design was not adopted is the clear space requirement between the EV chassis and the road. As this implies a tradeoff between coil plane angle and its cross-section, the VC configuration would require smaller coil area due to this clearance limit. An increase in the plane angle dictates a decrease in cross-section and vice versa. In this work, we show, both in simulations and experimentally, that the insertion of the ferrite plate  
Figure 1: Typical transmitter (lower coils) and DDQ receiver coils configuration. Figure 3: VC geometric model. VC 1 to VC 5 are the vertical coils. Figure 2: Side view of magnetic field lines logarithmic distribution. Colors represent magnetic field intensity [T]. to serve as a magnetic core for the receiver coils tips the scale in favor of this innovative design. Upon operating in the low B(H) curve regime of the ferrite, its high permeability compensates for the loss in cross-section area. Furthermore, the number of vertical coils can vary and increase as desired. Finally, one may add to the design another set of vertical coils, perpendicular to the set shown in Figure 4 and oriented with its long dimension parallel to the direction of motion. Such coils would pick up residual magnetic flux lines in the transverse direction. In the following, we examine a case study for the VC design composed of five equally distributed coils and compare it to the DDQ design. Once we establish a match in the small-scale model, we can confidently assert that constructing the large-scale model will follow the same principles as outlined in the simulations. Further studies will be required to optimize the VC design for number of coils, turns, spacing, etc. In the subsequent section, we begin by simulating the full-size receiver layout to understand its behavior.