Exploiting parallelism in resonators for large voltage gain in low power wake up radio front ends

This paper reports a lithium niobate (LiNbO3) resonator array that, when used as a passive voltage amplifier, can produce a passive resonant voltage gain among the highest reported thus far for low-power wake-up radio front-ends. The high voltage gain is obtained by exploiting parallelism in the form of 56 arrayed identical shear horizontal mode resonators. The array of LiNbO3 devices is designed to simultaneously enable a large static capacitance of 1.05 pF, a spurious mode free response, and a large figure of merit (FoM=kt2-0 of 120, all of which are subsequently demonstrated for the first time for a large resonator array. As a result, voltage gains over 20 or 26 dB have been achieved for highly reactive loadings of typical CMOS wakeup radio front-end input. In addition to the high voltage gain, the array also features a high Q of 915, which produces to 3 dB FBW of 0.1% for filtering noise and interference in the RF ambience.