Microwave photonics chips are used to generate, process, control, and distribute microwave signals. Microwave photonics integrated circuits, or chip modules, can also be called microwave photonics on-a-chip.
Microwave photonics-on-a chip enabled the shift from discrete circuits to chip-scale integrated circuits in applications such as satellite communication, terahertz systems, and 5G networks.
Signal processing and telecommunication systems have seen significant improvements since incorporating microwave photonics-on-a-chip into their systems.
Microwave photonics studies microwave-optical wave interactions
Ongoing research in the communications field is solving problems by combining concepts from photonics and microwave engineering. This integrated technology has helped the emergence of microwave photonics-on-a-chip, which has facilitated the shift from discrete circuits to chip-scale integrated circuits in applications such as satellite communication, terahertz systems, and 5G networks.
Let’s take a closer look at microwave photonics technology, specifically microwave photonics-on-a-chip, and the significant advancements they have made in telecommunications systems.
Microwave photonics chips are used to generate, process, control, and distribute microwave signals. Using photonic technology in microwave applications is advantageous due to the low-loss and wide bandwidth technology.
When using a digital-to-analog converter (DAC) in a communication system, the realization of DACs can be approached in two ways. The first approach is implementing DAC using digital and analog electronic circuits, which is a complex and costly approach. The disadvantages of implementing DACs using electronic circuits are speed limitations, sampling rate, and non-linearities. The second approach of realizing DACs is with microwave photonics integrated circuits. Microwave photonics-assisted DAC realization provides advantages such as:
- Broad bandwidth
- High sampling rates
- Excellent system performance
- Reconfiguration capabilities
Apart from the properties mentioned above, microwave photonics integrated circuits offer additional functionalities within an ultra-compact device dimension.
Where Are Microwave Photonics Used?
Microwave photonics integrated circuits, or chip modules, are excellent solutions for communication and signal processing systems, including:
- Microwave filters
- Microwave phase shifters
- Microwave mixers
- Photonic temporal differentiators
The integrated technology in microwave photonics called ‘microwave photonics-on-a-chip’ enables the low-cost development of compact-sized systems with high circuit density and multi-functionalities compared to its electronics counterparts.
Microwave photonics-on-a-chip technologies propelled communication and signal processing systems to new heights with their small, high-bandwidth, high-performance chip modules. Microwave photonics-on-a-chip technology began interfacing different semiconductor materials to increase light-matter interactions. The hybrid materials used to increase light-matter interactions include:
- Silicon nitride
- Silicon on insulator
- Indium phosphide
- Gallium arsenide
- Lithium niobate
By incorporating these hybrid materials in microwave photonics, significant advancements have been made in the performance of ultra-small and wide bandwidth-on-chip modulators, frequency synthesizers, and signal processors. The complete set of light sources, modulators, and detectors are fabricated using ultra-large-scale integration technology in a single microwave photonics chip.
Hybrid Materials in Microwave Photonics
The choice of hybrid material will influence the functionality, size, and performance of microwave photonics-on-a-chip. There are numerous hybrid materials to choose from to fabricate these chips. However, today, the semiconductor materials ruling the microwave photonics industry are indium phosphide, silicon on insulator, and silicon nitride.
These materials are critical for the active and passive integration of photonic components on-a-chip. These photonic components range from lasers, light sources, optical amplifiers, tunable devices, and waveguides, to name a few. Some of the advantages of hybrid semiconductor integrated microwave photonics include:
- Suitability for monolithic integration.
- Compatibility with the CMOS fabrication process.
- A wide bandwidth.
- A greater frequency tuning range.
- A high sampling rate.
- Low phase noise properties.
- Ultra-low propagation loss.
- Ultra-fast signal processing.
- Reconfigurable and multifunctional.
Telecommunication and signal processing systems have seen significant advancements by incorporating microwave photonics-on-a-chip in their systems. Cadence’s software supports the development of integrated electronic/photonic design automation (EPDA) environments.