Mar 29 (Fri) @ 11:00am: ”Integrated microwave photonics for communication and sensing,” Integrated Microwave Photonics for Communication and Sensing,” Alberto Montanaro, Permanent Researcher, CNIT (Italy)

Date and Time
Engineering Science Building (ESB), Rm 2001


Reconfigurable radiofrequency (RF) signal generation in the 30–300 GHz range is attractive for many applications including wireless and satellite communications, and radar systems. Microwave photonics techniques are widely used to achieve this goal. Specifically, optical techniques can be used for (i) generation of ultra-low phase noise (PN) reference clocks in the sub-THz domain and (ii) upconversion of baseband electrical signals at sub-THz carrier frequencies. Most of the demonstrations of such subsystems are based on bulk components, which are not suitable for the next generation wireless technologies such as 6G. Here we present the integrated version of these two building blocks, and we show how miniaturization could enable the use of such components in the next generation communication systems. We show as a perspective how these two components can be synergically integrated into a single chip to implement a compact photonic based sub-THz transmitter outperforming state of the  rt in terms of performances, with footprints comparable with the electronic counterpart.

Ultra-low noise carrier generation: The transmission of broadband signals with high subcarriers density requires ultra-low phase noise (PN), which is not easily attainable using conventional electronics. mm-wave carrier synthesis can be achieved using integrated silicon photonics (SiP). An optical frequency comb is generated through electro-optic modulation of a low-frequency reference clock with low PN. To select the desired tone out of the optical frequency comb, the key component is an integrated tunable distributed feedback resonator (DFBR) filter. The device has been fully packaged in an optoelectronic assembly, allowing RF signal delivery to remote peripherals through optical fiber. RF generation up to 110 GHz has been demonstrated as well as potential extension up to 200 GHz. Finally, the device has been successfully employed in a 93 GHz wireless transmission of 4Gbps QPSK.

Sub-THz upconversion: Graphene is ideally suited for optoelectronics. It offers tunable absorption at telecom wavelengths, ultra-high-frequency operation, and CMOS-compatibility. It can be used to realize both fast detectors and modulators and can be integrated on Si or SiN waveguides, therefore being an ideal material for integrated microwave photonics. We specifically focus on graphene photodetectors for microwave photonics applications. Graphene photo-bolometers rely on the fast change in conductivity due to excitation of hot carriers. This property can be used to realize optically aided sub-THz up/down converters with footprints drastically smaller than the current integrated systems. We show the use of these upconverters in a 93 GHz wireless data-link testbed performing (setup limited) 4Gbps QPSK transmission.


Alberto Montanaro holds a PhD in physics from École Normale Supérieure, Paris. During his PhD he worked in Thales Research and Technology, developing ultra high-speed graphene optoelectronic devices. He is currently a permanent researcher at CNIT - PNTLab, Italy. His principal domain of expertise is graphene microwave photonics. Its research interests are graphene optoelectronic devices and physics, and more recently integrated photonics for quantum communications.

Hosted by: Professor John Bowers

Submitted by: Federico Camponeschi <>