Chip-based broadband microwave photonic mixer with image rejection

Chip-Based Brillouin Processing for Microwave Photonic Phased Array Antennas

“…McKay et al demonstrated broadband image rejection downconversion using on-chip SBS by modulating the Brillouin pump over a broad bandwidth. In doing so, a broadband image rejection of 28 dB and 16 dB over of 100 MHz and 400 MHz bandwidths respectively was achieved [73], as shown in 16 (e). 16 (a, d) from [72], © 2020, Optica Publishing Group.…”

“…16 (a, d) from [72], © 2020, Optica Publishing Group. Figure 16 (e) from [73], © 2021, IEEE.) G. Brillouin Radio frequency sources RF sources are essential components in the PAA, and when used in conjunction with an MWP frequency converter, enable PAAs with widely tunable central frequencies.…”

“…It is desirable to reduce the pump power required to generate SBS gain in Brillouin waveguides. Although RF interferometric processing techniques reduce the pump power required by Brillouin-based MWP processors [73], [93], [115], relatively large pump powers are still required to generate Brillouin gain over a wide bandwidth. For example, approximately 350 mW of coupled pump power was used by McKay et al to generate 4 dB of Brillouin gain over a 400 MHz bandwidth [73] in a Ge:SiO 2 -As 2 S 3 PIC [94].…”

“…Although RF interferometric processing techniques reduce the pump power required by Brillouin-based MWP processors [73], [93], [115], relatively large pump powers are still required to generate Brillouin gain over a wide bandwidth. For example, approximately 350 mW of coupled pump power was used by McKay et al to generate 4 dB of Brillouin gain over a 400 MHz bandwidth [73] in a Ge:SiO 2 -As 2 S 3 PIC [94]. By analysing (13), the magnitude of Brillouin gain generated for a fixed pump power is related to the figure of merit (FOM), G S BS L e f f , and determines how effective a material platform is at generating Brillouin gain [63].…”

“…In this paper, we review the recent advances in MWP processing systems that utilise on-chip SBS. We highlight key functionalities required for optical beamforming networks, including filters [29], [69], RF sources [70], [71], frequency converters [72], [73], phase shifters [74]- [76], and TTDs [77], [78]. We outline the challenges that must be overcome to enable a fully-integrated Brillouin-based beamforming network suitable for element-level processing in PAAs, and provide perspectives on technical improvements that must be made to achieve the long-term performance goals for MWP processors [29], [79].…”