This thesis presents a practical topology for achieving highly efficient dual-side wireless power transfer (WPT). Traditional WPT systems with a diode rectifier on the secondary side lack flexibility in load matching, requiring the integration of an additional dc/dc converter at the back end. However, this approach leads to increased power losses and costs. In contrast, this thesis proposes the use of an active rectifier comprising MOSFETs, replacing the diode rectifier.

By employing a dual active bridge topology with dual-side control, optimal load tracking is achieved by tuning one side and communicating the desired duty cycle or phase angle to the other side. To address practical challenges, two key aspects are considered.

Firstly, synchronization is established between the generated current on the
secondary side and the new active rectifier, enabling efficient load tracking and the potential for zero voltage switching (ZVS). This is accomplished using a printed circuit board (PCB) equipped with zero current crossing detection (ZCCD), validated with an 85kHz test signal. The PCB triggers the PWM output of the secondary side microcontroller with a latency of less than < 50ns, utilizing the trip-zone digital compare sub-block integrated into the TMS320F28379D.

Secondly, seamless wireless communication between the primary and secondary sides is essential. While the secondary side can measure
the current and voltage across the load to adjust its duty cycle for optimal conditions, the primary side lacks this information. Therefore, the secondary side transmits the new duty cycle to the primary side to
ensure consistent power flow. The nRF24L01+ wifi module is utilized as a dual-purpose transmitter and receiver for achieving wireless communication. Validation of this wireless communication is performed
by remotely controlling an external LED, connected to the receiver side, from a distance of approximately 5m.accurately to the transmitted values. Additionally, a mathematical modeling approach is used to optimize power delivery and mitigate high-frequency noise by incorporating two parallel MLCC capacitors on a custom PCB near the nRF24L01+ module.

The displacement of a loudspeaker cone is not linearly proportional to the voltage/current at its input provided. This is due to electrical and mechanical limitations. The distortion is more noticeable at lower frequencies. This report is one of two reports, that will explain how to minimize this distortion. The motion of the loudspeaker cone will be measured and compared with the input voltage. This way the error in the output can be found. Finally, a system will adjust the current through the voice coil to decrease this error. An accelerometer is used as a sensor and the ADAU1777 is used to compensate for the error in output displacement. Finally, a voltage to current converter is used to convert and amplify the output voltage from the ADAU1777 into a current signal to drive the loudspeaker. This report focuses on the voltage to current amplifier. To begin the design, a problem definition and program of requirements will be given. Usually, loudspeakers are voltage driven. This report begins by first explaining why a current-driven loudspeaker delivers less distortion. Then an attempt is made to build a single operational amplifier (opamp) design that meets the requirements for a real load. For the single opamp design, a simple version of the operational transconductance amplifier (OTA) will be compared against a Howland model based on noise performance and circuit analysis, where it will be shown that the simple OTA has a larger signal to noise ratio and does not need to meet any additional criteria to maintain a high output impedance. However, the simple OTA still does not meet the Signal to Noise (SNR) . The simple OTA also did not meet the maximum Total Harmonic Distortion (THD) at 800 Hz. Then, a two opamp design will be constructed using a composite configuration to increase the SNR and decrease the THD. This design does meet the requirements given, at least for a purely resistive load. Then an electrical model of a loudspeaker, which has a complex impedance, will replace the resistive load. Now the composite design for the resistive load needs to be adjusted for the inductive characteristic of a loudspeaker at higher frequencies. The resulting design has a THD of 0.000427\%, a PM of 51$\degree$ and a SNR is 100.92 dB. All results will be given as simulations, because the current pandemic (COVID-19) does not make it possible to physically construct and measure this model. Micro-Cap 12 is used for circuit simulations and Slicap for circuit noise analysis.