Abstract
Since the parasitic voltage ringing and switching power losses limit the operation of active devices at elevated frequencies; therefore, a higher-order inductor-capacitor (LC) filter is commonly used, which offers extended attenuation above the cutoff frequency and thus, improves the total harmonic distortion (THD) of the amplifier. This paper applies the concept of integral sliding-mode control to a fourth-order class-D amplifier. Two fixed-frequency double integral sliding-mode (FFDISM) controllers are proposed, where one uses the inductor current while the other involves the capacitor current feedback. Their equivalent control equations are derived, but from the realization viewpoint, the controller using the capacitor current feedback is advantageous and, therefore, is selected for final implementation. The performance of the proposed FFDISM controller for fourth-order GaN class-D amplifier is confirmed using simulation and experimental results.
Highlights
Silicon transistors have dominated the power amplifiers industry due to the low-cost and well-established fabrication technology
Since the transistors in a linear power amplifier operate in the active region where power dissipation is significant, thereby they experience poor efficiency
Due to a narrow margin for improvement left in Si, the demand for high operating voltage, temperature and efficiency has enabled the trend towards wide band-gap (WBG) materials
Summary
Silicon transistors have dominated the power amplifiers industry due to the low-cost and well-established fabrication technology. In addition to advanced fabrication techniques like laterally diffused metal oxide semiconductor (LDMOS) [1,2], different control strategies such as Doherty’s architecture and load-modulation were adopted to improve the efficiency of a linear amplifier [3]. Due to a narrow margin for improvement left in Si, the demand for high operating voltage, temperature and efficiency has enabled the trend towards wide band-gap (WBG) materials. The attractive features such as a high electric breakdown field, low thermal impedance, and saturated electron drift velocity, motivated their rapid substitution for Si counterparts [4]. GaN high electron mobility transistor (HEMT) has become a potential candidate for large bandwidth and low-noise power amplifiers [5]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
