The performance of inductors at high frequencies and small sizes is one of the largest limiting factors in the continued miniaturization of dc-dc converters. Piezoelectric resonators can have a very high quality factor and provide an inductive impedance between their series and parallel resonant frequencies, making them a promising technology for further miniaturizing dc-dc converters. In this paper we analyze the impact of resonator parameters on the performance of the piezoelectric resonator based dc-dc converter, derive the optimal load impedance and efficiency limits, and analyze the impacts of varying conversion ratio and load impedance. This work is accompanied by a prototype dc-dc converter using a piezoelectric resonator fabricated from lithium niobate. The piezoelectric resonator has a quality factor of 4178 and a coupling coefficient, $k_t^2$ , of 29%. The converter is able to achieve high efficiency zero voltage switching and a continuously variable conversion ratio without the use of any discrete inductors. It achieves a maximum power output of 30.9 W at an efficiency of 95.2% with a power density of 6.76 $\frac{\text {W}}{\text {cm}^3}$ .

中文翻译：

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用于压电功率转换的优化谐振器

电感器在高频和小尺寸下的性能是DC-DC转换器持续小型化的最大限制因素之一。压电谐振器可以具有很高的品质因数，并且可以在串联谐振频率和并联谐振频率之间提供电感阻抗，这使它们成为进一步使dc-dc转换器小型化的有前途的技术。在本文中，我们分析了谐振器参数对基于压电谐振器的DC-DC转换器性能的影响，得出了最佳负载阻抗和效率极限，并分析了变化的转换比和负载阻抗的影响。这项工作伴随着使用由铌酸锂制成的压电谐振器的原型DC-DC转换器。压电谐振器的品质因数为4178，耦合系数为$ k_t ^ 2 $ ，占29％。该转换器能够在不使用任何分立电感器的情况下实现高效率的零电压开关和连续可变的转换比。它以95.2％的效率和6.76的功率密度实现了30.9 W的最大功率输出。$ \ frac {\ text {W}} {\ text {cm} ^ 3} $ 。