Fully integrated hybrid microwave photonic receiver

Microwave photonic receivers, featuring the advantages of wide operation bandwidth and flexible reconfigurability, are the promising candidate desired for breaking the bandwidth limitation of traditional RF receivers, which would have broadened applications prospects in global wireless communication, broadband radar systems, and advanced multifunctional RF systems.

 

However, most reported microwave photonic receiver systems are based on discrete photonic devices, resulting in disadvantages of large size, high power consumption, and unstable system performance. In recent years, driven by urgent requirements on size, weight, and power consumption (SWaP) oriented to miniaturized application scenarios and the technological maturity of photonic integrated circuits (PICs), the implementation of microwave photonic microsystems based on photonic integrated chips has been considered as an upgrade path towards practical application.

 

However, chip-scale fully integrated microwave photonic receivers have not been reported due to the various shortcomings of mainstream material platforms. Therefore, it is challenging in the short term to realize high-performance monolithic integrated microwave photonic microsystems based on a single material platform.

 

To solve this problem, the research group led by Prof. Minghua Chen from Tsinghua University together with Prof. Weiwen Zou from's team from Shanghai Jiao Tong University and Prof. Xingjun Wang's team from Peking University have proposed a fully integrated hybrid microwave photonic receiver (FIH-MWPR) microsystem by hybrid integrating a monolithic silicon-on-insulator (SOI) photonic circuit chip with a semiconductor laser chip, and then demonstrated its de-chirp processing capability for broadband linear frequency-modulated (LFM) radar signals. The research results are published in Photonics Research, Volume 10, No. 6, 2022 (Jiachen Li, Sigang Yang, Hongwei Chen, Xingjun Wang, Minghua Chen, and Weiwen Zou. Fully integrated hybrid microwave photonic receiver[J]. Photonics Research, 2022, 10(6): 06001472).

 

In this FIH-MWPR, the SOI-based photonic chip includes most of the required functional components: high-speed phase modulators, tunable photonic signal processors, and a photodetector array, while the semiconductor laser chip provides the continuous-wave optical carrier. The SOI-based photonic chip and the semiconductor laser chip are comprised into the same substrate based on the low-loss micro-optics coupling method and assembled into a compact package.

 

The FIH-MWPR module supports a broad operation bandwidth of 2~18 GHz. Moreover, benefiting from the hybrid integration of all optoelectronic components, the packaged FIH-MWPR module exhibits a compact volume of 6 cm3 and low power consumption of 1.2 W, which have been significantly promoted compared to the previously reported results. The research group has utilized the FIH-MWPR module as a de-chirp receiver to process the broadband LFM radar signals at different frequency bands (S-, C-, X-, and Ku-bands) and demonstrated its high-resolution ranging capability.

 

The researchers point out that the silicon-based photonic integration technology combined with the development of hybrid integration technology would promote more technical advantages and practical applications in the field of microwave photonics and high-speed optical communication.

 

Schematic diagram of the FIH-MWPR and photo of the packaged module

 

In this paper, the research group has reported an integrated microwave photonic receiver microsystem based on the silicon-based photonic integrated chips and the hybrid integration method, which balances the performance superiority with the requirements of SWaP. The results can facilitate the research of high-resolution inverse synthetic aperture radar imaging and advanced multifunction RF systems, benefiting the practical application of microwave photonic technology.