Back to Search
Start Over
A Radio Frequency Nonreciprocal Network Based on Switched Acoustic Delay Lines.
- Source :
-
IEEE Transactions on Microwave Theory & Techniques . Apr2019, Vol. 67 Issue 4, p1516-1530. 15p. - Publication Year :
- 2019
-
Abstract
- This paper demonstrates the first nonreciprocal network based on switched low-loss acoustic delay lines. The four-port circulator is built upon a recently reported frequency-independent, programmable, nonreciprocal framework based on switched delay lines. The design space for such a system, including the origins of the insertion loss (IL) and harmonic responses, is theoretically investigated, illustrating that the key to better performance and low-cost modulation signal synthesis lies in a large delay. To implement a large delay, we resort to in-house fabricated low-loss, wideband lithium niobate (LiNbO3)SH0 mode acoustic delay lines employing single-phase unidirectional transducers. The four-port circulator, consisting of two switch modules and one delay line module, has been modularly designed, assembled, and tested. The design process employs time-domain full circuit simulation, and the results match well with measurements. An 18.8-dB nonreciprocal contrast between IL (6.6 dB) and isolation (25.4 dB) has been achieved over a fractional bandwidth of 8.8% at a center frequency 155 MHz, using a record low switching frequency of 877.19 kHz. The circulator also shows 25.9-dB suppression for the intramodulated tone and 30 dBm for IIP3. Upon further development, such a system can potentially lead to future wideband, low-loss chip-scale nonreciprocal radio frequency systems with unprecedented programmability. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00189480
- Volume :
- 67
- Issue :
- 4
- Database :
- Academic Search Index
- Journal :
- IEEE Transactions on Microwave Theory & Techniques
- Publication Type :
- Academic Journal
- Accession number :
- 135773726
- Full Text :
- https://doi.org/10.1109/TMTT.2019.2895577