The Importance of Electromechanical Switches in Aerospace and Defense Systems

Electromechanical switches are prized for their role in managing aerospace and defense signal routing and power switching needs, presenting predictable performance that more conventional components cannot match. As they rely on mechanically actuated contacts, these switches can deliver stable insertion loss, isolation, and power-handling characteristics that benefit basic aircraft power-distribution panels and spaceborne equipment alike. In this blog, we will examine several major electromechanical switch types used across aerospace and defense applications before highlighting a few areas where they are particularly imperative, ensuring you are equipped with the knowledge necessary to make more informed purchasing decisions.

Standard Types of Electromechanical Switches

Several types of electromechanical switches are commonplace across aerospace and defense platforms, with the following being the most notable options.

• Toggle Switches: Toggle switches rely on a lever being manually moved back and forth to open or close a circuit, providing clear tactile feedback and visual indication of position.
• Rocker Switches: In a similar manner to toggle switches, rocker switches have a pivoting actuator that rocks to either side to complete or break a circuit. Usually, they have a broader but more low-profile actuation surface when compared to their counterparts.
• Slide Switches: Slide switches contain a small actuator that moves linearly along a track to shift internal contacts between circuits, serving compact panels or equipment with simple, low-force actuation.
• Rotary Switches: These switches rotate through multiple detented positions to route signals or change operational modes.
• Pushbutton Switches: Pushbutton switches operate as their name implies, either maintaining their state until their button is pressed or using a momentary mechanism that immediately reverts back after actuation.
• RF and Coaxial Electromechanical Relay Switches: These switches can route radio-frequency and microwave signals, doing so by mechanically repositioning conductive contacts inside a coaxial housing that maintains impedance and shielding. A solenoid or latching actuator is what specifically moves a contact assembly to connect an input port to a selected output port, creating a stable, low-loss RF path while isolating all others.

Along with choosing the appropriate electromechanical switch type for the particular setup, aerospace and defense operations often demand hermetically sealed, environmentally hardened, or other specially-designed variants to appropriately withstand everything from dust ingress to pressure variations.

Major Aerospace and Defense Applications of Electromechanical Switches

Aircraft Cockpits and Control Panels

Electromechanical switches are employed for many human-machine interactions across military and civilian aircraft. When not handled through touchscreen or software interfaces, these switches provide pilots with tactile control over landing-gear actuation, cabin and exterior lighting, hydraulic and fuel-pump management, avionics power distribution, environmental-control units, and many other systems.

Toggle, rocker, and rotary switches are the most prominent forms of switches in these areas, with all of their actuation methods providing a clear physical indication of state for operators to confirm instantly. Moreover, as electromechanical switches can be configured in single-pole or multi-pole arrangements, they support complex cockpit logic where a single input may need to energize multiple circuits, interlock subsystems, or reroute electrical power during abnormal events. 

Communication, Navigation, Radar, and Electronic Warfare Systems

Some of the most technically demanding uses of electromechanical switches arise in RF, microwave, radar, and electronic warfare (EW) equipment. In these systems, such switches serve as signal-routing devices for RF paths to direct energy between antennas, receivers, transmitters, filters, test points, and other components. By reconfiguring these paths as needed, the system can select between different frequency bands, route signals through alternate processing chains, safeguard sensitive receivers during high-power transmit events, and control the timing and sequencing of radar and EW waveforms.

To support these functions seamlessly while still holding up to the vibration, thermal extremes, and persistent electromagnetic interference (EMI) that is all commonly faced by defense and aerospace platforms, electromechanical switches are available in several advanced formats.

• Wideband Coaxial Relay Switches: Well-suited for systems that must operate across many frequency bands without separate front-end hardware, these wideband coaxial relay switches present multi-octave coverage. They often appear in EW receivers, SIGINT equipment, and broadband radar systems that demand flexible signal routing.
• Waveguide Electromechanical Switches: Supporting radar transmit chains and high-power microwave systems, these switches are built into a rigid, hollow-metal transmission line known as a waveguide section, which confines and directs microwave or millimeter-wave energy. Utilizing a rotating vane, sliding shutter, or conductive paddle that moves into the waveguide, the element can block or redirect an electromagnetic field when inserted and allow energy to pass when retracted.
• Latching Electromechanical Switches: Latching switches use a mechanical or magnetic latching mechanism that holds a switch’s position after actuation without taking up continuous coil power or generating excess heat.

Space and Satellite Systems

In spaceborne systems, electromechanical waveguide and coaxial switches are central to redirecting microwave energy between payload components, allowing satellites to switch antenna feeds, reconfigure transponders, or activate backup communication modules when a primary pathway fails. Space-qualified switch options are specifically built with hermetic sealing, low-outgassing materials, contamination-controlled assembly, and mechanical structures that are meant to withstand everything from the forces of launch vibration to continued vacuum and radiation exposure.

Find Quality Electromechanical Switches for Aerospace and Defense Needs on AFR Enterprises

In summary, electromechanical switches offer a combination of mechanical ruggedness and electrical performance that few alternatives can match for aerospace and defense tasks. With many different types of electromechanical switches curated to meet the unique requirements of such applications, always be sure to choose trustworthy distributors like ASAP Semiconductor and its range of purchasing platforms to secure high-integrity products that underpin safe, effective, and long-lasting systems.

On AFR Enterprises, a website owned and operated by ASAP Semiconductor, we present a broad catalog of switches and other components that meet MIL-SPEC, NAS, and other such industry standards. Moreover, with the assurance that everything we feature is directly traceable to leading manufacturers and readily available for purchase, you can confidently obtain all that you need for operations here. To benefit from competitive procurement options and dedicated customer service, get in touch with our team at your earliest convenience.