Addressing EMI and signal integrity challenges on eVTOL aircraft

As eVTOL aircraft near deployment on a mass scale and as cities continue to grow, managing EMI while balancing SWaP requirements will be all the more important.

Imagine you’re walking down the street in midtown Manhattan sometime in the 2030s.

As you make your way through a crosswalk, you notice vehicular traffic has thinned out noticeably lately due to the all-electric revolution in Urban Air Mobility (UAM) that has taken major metropolitan areas by storm in recent years.

As you look up, you see multiple Electric Vertical Takeoff and Landing (eVTOL) aircraft flying by and in between New York City’s vast rows of skyscrapers. Despite being nearly as numerous as New York’s famous yellow taxi cabs at this point, these quick, nimble electric aircraft whizz through the city skyline with ease while effortlessly avoiding structures and other aircraft. Each day, hundreds of thousands of passengers are promptly flown to their destinations in a fraction of the time it used to take to drive through the city’s congested boroughs, thanks to the development of eVTOL platforms.

This future is right on the horizon, though it’s one that will see the greatest density of aircraft flying through urban areas that these places have ever experienced before. Deploying eVTOL aircraft en-masse throughout large urban centers like New York City, Los Angeles, London, Sydney, Paris, and more will demand that essential signal is not disrupted by the many sources of electromagnetic interference (EMI) and radio frequency interference (RFI) scattered throughout dense population areas.

EMI/RFI filtering capabilities in eVTOLs must not only be thoroughly dependable in everything, including harsh environments, but also account for size, weight, and power (SWaP) considerations as these aircraft feature lightweight airframes and compact design features to maximize maneuverability and performance.

Urban EMI Challenges are Going to Grow

Major cities around the globe have a dense concentration of electronic devices, communication networks, power infrastructure, and other sources that typically lead to a high level of EMI and RFI. This concentration is only expected to grow in the coming years.

In North America alone, there were more than 300 million cellular mobile connections by early 2024 and more than five billion unique mobile phone users worldwide, and these numbers are expected to continue rising. Mobile data traffic growth is expected to triple in North America heading into 2027, and by 2029, 5G is expected to account for more than 70% of mobile data traffic worldwide.

The further expansion of mobile device and mobile network usage in the coming years will only add to EMI/RFI concentration in cities. Other major sources of man-made EMI, such as television and radio transmissions, public transportation systems, and airport radar, are also projected to grow coinciding with the expansion of urban areas.

By 2050, a further 2.5 billion people could integrate into urban areas, meaning approximately 68% of the global population would live in cities. Meanwhile, by 2030, the world is projected to undergo a further 1.2 million square kilometers of urban build-up.

All these factors indicate that the urban EMI/RFI environment is going to become more concentrated in the coming years, especially in areas where fleets of eVTOL aircraft are projected to be flying around the clock. It’s paramount that developers choose the right EMI filtering solution for their system; one that consistently maintains clear signal integrity in dense EMI/RFI environments while catering to SWaP needs.


Amphenol Aerospace filter adapters offer a practical and cost-effective approach to integrating EMI/EMP protection into an existing system.

eVTOL aircraft are unique in their needs and capabilities. Scaling their development and deployment requires special attention paid to their SWaP requirements.

Reliance on electric propulsion systems and battery technology means eVTOL SWaP considerations are critical. Because eVTOL platforms need to extend flight range and payload capacity as much as possible, improving energy efficiency by reducing weight and power requirements is a priority. Modern battery technology demands minimizing weight and power to optimize performance within current limitations.

Enhanced SWaP directly impacts payload capacity and flight durations, which is crucial for accommodating passengers, cargo, or equipment, as well as adhering to strict aviation regulations regarding weight and performance for certification and safety.

Additionally, eVTOLs need to minimize size and weight as much as possible in urban settings where airspace is constrained and landings on rooftops and small landing pads will be commonplace.

Amphenol Aerospace Filter Connectors are available in a selection of Mil-Spec configurations, including 38999 (shown above), MIL-DTL-5015, and more.

Filtering solutions in aircraft are typically implemented at various levels such as the printed circuit board and system-level.

At the PCB level, several common filtering methods are employed to address specific frequency ranges and interference sources, including passive components such as capacitors, inductors, and resistors strategically integrated into the circuit layout to mitigate conducted and radiated EMI. Capacitors, for instance, serve to shunt high-frequency noise to the ground, while inductors attenuate low-frequency interference. Moreover, ferrite beads, characterized by their high impedance at higher frequencies, are often utilized to suppress conducted EMI along power and signal lines.

In addition to passive components, active filtering techniques may also be employed at the PCB level, leveraging devices such as semiconductor operational amplifiers or specialized integrated circuits designed for filtering applications.

System-level filtering strategies feature a broader range of techniques aimed at mitigating EMI across interconnected subsystems and interfaces within the aircraft's electronic architecture. This includes the implementation of shielding measures to contain electromagnetic emissions and susceptibility, as well as the adoption of advanced filtering algorithms and digital signal processing techniques in software-defined systems.

Depending on your system needs and constraints, developers may be able to eliminate the need for some of these components by implementing EMI protection at the connector level, saving valuable space and weight in your assembly. This also means existing systems don’t need to undergo a total design overhaul to implement EMI protection offered through Amphenol filter connectors. 

Amphenol Aerospace offers a broad selection of standard and Mil-Spec circular connectors with a large variety of filter options to accomplish this. Our filter connectors utilize a selection of various low-pass filters to effectively mitigate medium and high-frequency interference, depending on the threat profile. These filters utilize capacitors, planar inductors, and ferrite inductors to suppress unwanted signal noise.

The Pi Filter, comprising two planar capacitors with a ferrite inductor in between, offers a steep insertion loss curve. The C Filter employs a single planar capacitor, providing a simple and cost-effective design that often outperforms multi-component configurations.

The C-L Filter integrates a planar capacitor followed by a ferrite inductor, ideal for scenarios where source impedance exceeds load impedance. The L-C Filter utilizes a ferrite inductor followed by a single planar capacitor, suitable for instances where load impedance surpasses source impedance. Lastly, the T Filter, composed of two ferrite inductors with a single planar capacitor in between, demonstrates superior high-frequency performance. These filter configurations can be tailored to offer robust EMI suppression and signal preservation in diverse electronic systems throughout your assembly.

Visit our EMI Filter Solutions page for more information on how Amphenol Aerospace filter solutions can help you meet your electromagnetic capability (EMC) requirements.