Freeze-drying has been widely adopted in the manufacturing of biologics for producing vaccines and protein-based therapeutics that are highly unstable in liquid form. Radio-frequency-assisted lyophilization (RFAL) can significantly accelerate drying by applying highly controllable volumetric heating. In this article, we design, for the first time, a quasi-random field (qRF) system. The system demonstrates: 1) primary drying acceleration and 2) very high uniformity with two different types of antennas at 8 GHz. Specifically, a double-ridged horn antenna and a wideband conical antenna are designed and placed inside a metallic enclosure [reverberation chamber (RC)] to excite electromagnetic waves inside a standard R&D freeze-dryer. The most suitable antenna type and location are determined using full-wave simulations. Compared with the standard 2.45 GHz frequency of operation, the electromagnetic field uniformity is improved by 2.47 times at 8 GHz. Furthermore, we show a primary drying acceleration of 81% with the wideband conical antenna and 119% with the double-ridged horn antenna using only 25 W of RF power. Residual moisture content measurements validate the proposed design for both implementations.

中文翻译：

---

优化冻干射频加热的统计场均匀性：建模和实验验证

冷冻干燥已广泛应用于生物制剂的生产中，用于生产液体形式高度不稳定的疫苗和基于蛋白质的治疗剂。射频辅助冻干（RFAL）可以通过应用高度可控的体积加热来显着加速干燥。在本文中，我们首次设计了准随机场（qRF）系统。该系统展示了：1) 初级干燥加速和 2) 两种不同类型的天线在 8 GHz 下具有非常高的均匀性。具体来说，设计了双脊喇叭天线和宽带锥形天线，并将其放置在金属外壳[混响室（RC）]内，以在标准研发冷冻干燥机内激发电磁波。最合适的天线类型和位置是使用全波模拟确定的。与标准2.45GHz工作频率相比，8GHz下电磁场均匀性提高了2.47倍。此外，我们还表明，仅使用 25 W 的射频功率，宽带锥形天线的初级干燥加速度为 81%，双脊喇叭天线的初级干燥加速度为 119%。残余水分含量测量验证了两种实施方式的建议设计。