在当今的“东西互联网上”，设备主要在短速范围内连接到短速度，这是一种环境，其中表面声波（SAW）器件多年来的承诺，导致智能手机的缩小缩小。然而，为了获得更快的速度，SAW器件需要在更高的频率下运行，这限制了输出功率并且可以恶化整体性能。新的SAW设备希望为这些设备提供向前推进的路径，以达到更高的频率。
中国的一支研究人员展示了一个锯装置，可以实现比大多数电流设备高的频率高六倍。通过嵌入式换铝和金刚石层上的嵌入式换能器（IDTS），该团队的装置也能够显着提高输出。他们的结果本周发布Applied Physics Letters, from AIP Publishing.
“We have found the acoustic field distribution is quite different for the embedded and conventional electrode structures,” said Jinying Zhang, one of the paper’s authors. “Based on the numerical simulation analysis and experimental testing results, we found that the embedded structures bring two benefits: higher frequency and higher output power.”
表面声波器件通过将电能转换为声能而发射高频信号。这通常用压电材料进行，该压电材料能够在电压的存在下改变形状。通常将IDT电极放置在压电材料顶部，以执行该转换。
Ramping up the operational frequency of IDTs — and the overall signal speed — has proven difficult. Most current SAW devices top out at a frequency of about 3 gigahertz, Zhang said, but in principle it is possible to make devices that are 10 times faster. Higher frequencies, however, demand more power to overcome the signal loss, and in turn, some features of the IDTs need to be increasingly small. While a 30 GHz device could transmit a signal more quickly, its operational range becomes limited.
“The major challenge is still the fabrication of the IDTs with such small feature sizes,” Zhang said. “Although we made a lot of efforts, there are still small gaps between the side walls of the electrodes and the piezoelectric materials.”
To ensure that the transducers had the proper feature size, Zhang’s team needed a material with a high acoustic velocity, such as diamond. They then coupled diamond, a material that changes its shape very little with electric voltage, with aluminum nitride, a piezoelectric material, and embedded the IDT inside their new SAW device.
与使用锯的传统设备相比，所得装置以17.7GHz的频率操作，并提高功率输出10％。
张说，“最惊讶的是，对美国最感到惊讶的是，声场分布对于嵌入式和常规电极结构非常不同，”张说。“我们之前没有想过它。”
Zhang said she hopes this research will lead to SAW devices used in monolithic microwave integrated circuits (MMICs), low-cost, high-bandwidth integrated circuits that are seeing use in a variety of forms of high speed communications, such as cell phones.
Filed Under:Rapid prototyping
