EAGER: Phononic Amplification for Active Filtering at Radio Frequency

非技术性：对无线通信系统的速度和可靠性的需求不断增长。因此，解决这些系统的复杂性是一项比十年前艰巨得多的任务。例如，在现有技术的智能电话中存在同时操作的多个无线电。随着5G无线通信网络的即将到来，传输频率预计将超过10 GHz。 低噪声放大和特定频率的选择（滤波）是从天线接收信号的关键过程。传统的无源声滤波器技术不能有效地解决这种复杂系统的需求，特别是在高频下。拟议的工作研究了一类新的设备，将提供同时低噪声放大和射频（RF）信号滤波。在单个芯片上集成多个RF前端的能力将为无线通信系统带来前所未有的可能性。 单个设备可以彻底改变接收器前端架构，并为更复杂的无线电系统铺平道路。这类新的电子器件可以开辟一个新的研究和开发领域，具有巨大的商业应用潜力。技术：本项目的技术重点是进一步探索和提高机电谐振器件中声子放大的概念，以开发频率在GHz范围内的窄带有源滤波器。 这种器件可以通过消除传统的半导体放大器并将放大移动到同时进行频率选择的声学域来显著简化和改进RF前端。 声子放大基于微纳米机械谐振腔中的载波-声子相长干涉效应，并且在许多方面是激光和光学放大的声学等效物。 从外部电源吸收功率，机械振动（声子）可以由于载流子-声子相互作用而被放大。 在电域中的结果是在机械结构的谐振频率周围的窄带宽内的负等效电阻。 负电阻与电阻性负载组合可充当放大器，其吸收来自泵浦源的功率并将放大的RF功率递送到负载。 由声子放大器提供的高度选择性滤波可以显著地放松动态范围要求，并且因此放松RF模数转换器的功耗。 因此，声子放大器非常适合具有直接采样架构的现代RF收发器，其中RF信号在不被下变频的情况下被处理。 为了满足线性度和功率处理要求，将设计和实现这种器件的二维机械耦合（电并联）阵列。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nontechnical:There is an ever-growing need for speed and reliability of wireless communication systems. Addressing the complexity of such systems is therefore a much more daunting task than it was a decade ago. For example, there are multiple radios operating at the same time in a state of the art smartphone. With the imminent advent of 5G wireless communication networks and beyond, transmission frequencies are expected to reach beyond 10 GHz. Low-noise amplification and selection of specific frequencies (filtering) are crucial processes on signals received from the antenna. Conventional passive acoustic filter technologies are not capable of efficiently addressing the needs of such complex systems, especially at high frequencies. The proposed work investigates a new class of devices that will provide simultaneous low-noise amplification and filtering of radio frequency (RF) signals. The ability to integrate multiple RF front-ends on a single chip will enable a host of unprecedented possibilities in wireless communication systems. Individual devices can revolutionize receiver front-end architectures and pave the way to more sophisticated radio systems. This new class of electronic devices can open up a new area of research and development with great potential for commercial applications.Technical:The technical focus of this project is to further explore and enhance the concept of phononic amplification in electromechanical resonant devices for development of narrow-band active filters with frequencies in the GHz range. Such devices can significantly simplify and improve RF front-ends by eliminating the conventional semiconductor amplifiers and moving the amplification into the acoustic domain, where frequency selection takes place simultaneously. Phononic amplification is based on carrier-phonon constructive interference effect in micro to nanoscale mechanical resonant cavities and is in many ways the acoustic equivalent of LASER and Optical Amplification. Absorbing power from an external electrical power source, mechanical vibrations (phonons) can be amplified due to carrier-phonon interactions. The result in the electrical domain is a negative electrical equivalent resistance within a narrow bandwidth around the resonance frequency of the mechanical structure. A negative resistance in combination with a resistive load can act as an amplifier absorbing power from the pump source and delivering amplified RF power to the load. Highly selective filtering provided by the phononic amplifiers can significantly relax the dynamic range requirement and therefore power consumption of RF analog to digital converters. Phononic amplifiers are therefore well suited for modern RF transceivers with direct sampling architectures, in which the RF signal is processed without being down-converted. To meet the linearity and power handling requirements, two-dimensional mechanically coupled (electrically parallel) arrays of such devices will be designed and implemented.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.