Abstract
This work presents a class of micro-electro-mechanical system (MEMS)-driven radio frequency filters in the X-band. The X-band center frequencies are achieved by resorting to the third-order antisymmetric Lamb wave mode (A3) in a 650-nm-thick Z-cut lithium niobate thin film. A novel bandwidth (BW) widening technique based on using the self-inductance of the top interdigital transducers and bus lines is proposed to overcome the limitations set by the electromechanical coupling ( {k} _{t}^{2} ) and satisfy the demands in miniaturization and wide BW. Four different designs of the filters are designed and fabricated to show the trade-off among BW, insertions loss (IL), out-of-band rejections, and footprint. Due to the spurious-free and high- {Q} performance of the A3 lithium niobate resonators, the fabricated A3 lithium niobate filters have demonstrated small in-band ripples and sharp roll-offs. One of these fabricated has demonstrated a 3-dB BW of 190 MHz, an IL of 1.5 dB, and a compact footprint of 0.56 mm2. Another design is fabricated to demonstrate a 3-dB BW of 170 MHz, an IL of 2.5 dB, an out-of-band rejection of 28 dB, and a compact footprint of 1 mm2.
Original language | English (US) |
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Article number | 9337207 |
Pages (from-to) | 1602-1610 |
Number of pages | 9 |
Journal | IEEE Transactions on Microwave Theory and Techniques |
Volume | 69 |
Issue number | 3 |
DOIs | |
State | Published - Mar 2021 |
Keywords
- 5G wireless communications
- Acoustic filters
- Internet of things
- antisymmetric lamb waves
- bandwidth (BW) widening
- lithium niobate
- micro-electro-mechanical system (MEMS)
- self-inductance
ASJC Scopus subject areas
- Radiation
- Condensed Matter Physics
- Electrical and Electronic Engineering