An FPGA-Based On-the-Fly Reconfigurable Low-Power SHEPWM Inverter with a Compact SiP Implementation

This paper presents a selective harmonic elimination pulse-width modulation (SHEPWM) full-bridge inverter featuring real-time on-the-fly reconfigurability of output waveform amplitude and frequency using a field-programmable gate array (FPGA). The inverter is integrated on a compact threedimensional (3D) system-in-package (SiP) using low-temperature co-fired ceramics (LTCC) as a substrate, reducing the printed circuit board (PCB) area. Validated through simulations and measurements at 0.12W and 1.2W peak output power, the inverter cancels harmonics up to the 34 ^th order at switching nodes. With an LC filter having a 20 kHz cut-off frequency, total harmonic distortion (THD) at the load is below 5.1% for alternating current (AC) output signals, varying in modulation index (MI) from 0.2 to 0.9 and output frequencies from 5 kHz to 10 kHz. The results also showed that for the same inverter conditions and output THD, the SHEPWM inverter with 0.12W output power has an average of 17.3% and 4.2% better efficiency than a natural PWM (NPWM) inverter with an output frequency of 4 kHz and 10 kHz, respectively. For the inverter of 1.2W output power, the SHEPWM inverter maintains better efficiency than the NPWM counterpart, by an average of 2.3% and 6.9%, respectively.