Microwave Photonics Programs at DARPA

Programmable optical processor chips: toward photonic RF filters with DSP-level flexibility and MHz-band selectivity

“…For the integrated microwave photonic implementation of coherent filters, both approaches in Figure 2, that is, filter shape transfer and filter shape synthesis, have been demonstrated. As a salient example for such a filter shape transfer approach, Rasras et al [52] demonstrated an RF notch filter using an RAMZI comprising a four-ring resonator-assisted symmetric MZI with a total chip area of 1.75 mm 2 and an RR FSR of 43 GHz. This work demonstrated a notch depth >30 dB, a 3-dB bandwidth <1 GHz, a tuning range >15 GHz, and the capability of multiple notches at the same time.…”

“…Developing low-cost and flexible RF front ends is of high interest for both academia and industry [1], driven by the rapid and incessant increase of demand for data traffic in wireless communications for the consumer market [2], for example, the next-generation 5G systems, and highfrequency applications for defense and space industries [3]. Alongside the conventional all-electronics solutions that are supported by high industrial maturity but facing general challenges of bandwidth, tunability, and power consumption, microwave photonics offers practical solutions with desirable features such as large instantaneous bandwidth, low electromagnetic interference, wide continuous tunability, and high power efficiency [4][5][6][7].…”

Integrated Microwave Photonics for Wideband Signal Processing

“…Such dynamic filtering performance is essential in applications such as radar and surveillance where RF disturbances are very likely to occur at random frequencies [2,52,53]. The ability to provide continuous tuning for arbitrary frequencies allows the system to adapt to the constant changes in the front-end operational requirements, where achieving such performance in the electronic domain still remains a challenge.…”

“…Bringing together the worlds of radiofrequency (RF) engineering and optoelectronics, the field of MWP has recently attracted great interest from both the research and the commercial communities where its importance has been identified in emerging applications including medical imaging, future 5G networks, and subterahertz systems. It offers the unique abilities to enable key functionalities in microwave systems such as filtering, arbitrary waveform generation, frequency up/down conversion and instantaneous measurement that are either complex or even not directly possible in the radiofrequency domain [1][2][3][4][5][6][7][8][9]. As the role of MWP develops from niche to widespread applications, it becomes important to replace systems that rely exclusively on discrete optoelectronic devices and fiber-based components.…”

Analogue RF over fibre links for future radar systems

“…This has in turn led to renewed interest from the defence industry. In the last few years, work in this area has been published by several major defence institutions including Thales, Lockheed Martin, Northrop Grumman and US and European defence agencies [2][3][4][5].…”