A Guide to Cooling Radar Electronics

A Guide to Cooling Radar Electronics, over a radar system in the background.

Radar systems are essential for a wide range of industries. These detection systems use radio waves to identify and locate objects. From the medical field and the military to engineering and robotics, radar is an integral tool for many professional applications.

The military applies radar in many conditions and deploys some of the most sophisticated systems to aid in defending our nation. Radar helps military personnel detect dangerous objects, upcoming weather conditions, or potential strikes. Radar systems can be mounted on mobile units or used in stationary positions. Either way, radar electronics help keep military personnel safe while in the field and civilians safe at home.

Military radar equipment must meet specific thermal management requirements. Radar electronics produce massive amounts of heat, which can harm performance. The equipment must be kept below certain temperatures to prevent overheating. One strategy for this obstacle is using cooling systems and other thermal management technology, which can help heat dissipate, preventing overheating.

Use of Radar Electronics in the Military

Radar systems are essential tools for many military applications. These electromagnetic sensors can detect, identify, and track objects within certain distances. The signals send out short pulses, and objects in their path reflect the pulses back to the system. In other words, radar works similarly to echoes.

The military uses radar in many applications, including:

  • Mapping: Teams use radar in aircraft and other vehicles to produce 2D or 3D maps of nearby terrain. These maps help personnel understand the topography and landscapes ahead of arrival. Radar can also detect rain, haze, or other conditions that might affect travel.
  • Weather-sensing: Weather-sensing radar systems can determine precipitation intensity and other features of upcoming storms. They also detect storm speed by measuring how long it takes for signals to return to the towers.
  • Search and rescue: The military also uses radar for search and rescue purposes. The systems can locate ships and airplanes over long distances. They are known for precise accuracy, with the ability to pinpoint exact locations and recover lost vehicles and people. Overall, radar makes it easier to conduct immediate rescues.
  • Tracking: Target radar systems focus on a single object and anticipate its future position. Tracking systems judge an object’s angle and current trajectory to predict future movements. The signals can also detect the size and specific features of objects.

Overall, radar electronics are essential for military security, allowing teams to detect various physical features.

The Importance of Military Electronics Thermal Management

Since radar electronics play important roles in military applications, designers must address thermal management issues. Radar systems can generate significant heat during use, especially when combined with high environmental temperatures. Overheating could lead to system failures or damage the equipment. Maintaining the proper temperatures ensures military personnel can keep radar equipment operable and safe.

Image shows military radar in the field. Text reads: Radar systems can generate significant heat during use, especially when combined with high environmental temperatures.

Design engineers use creative strategies to keep radar systems functional and at the correct temperatures. As military technology continues to become more advanced, engineers must find new ways to manage heat production. For instance, high-powered tools are more likely to produce excessive heat. Engineers have to balance advanced performance with safe temperatures. In addition, the systems must meet specific environmental challenges like:

  • Shocks or vibrations
  • Harsh temperatures
  • Extended uses
  • Dust
  • Fog

Various thermal management solutions work continuously to keep radar electronics at the proper temperatures.

Thermal Management Solutions for Radar Electronics

Military systems operators can use a combination of passive and active thermal technologies to provide effective thermal management. As radar systems advance in size and sophistication, higher performing thermal management strategies must be deployed, including:

Why are Passive Two-Phase Solutions Important?

Passive two-phase heat transfer devices, such as heat pipes, HiK™ plates or vapor chambers can help take local, high heat flux sources and introduce a lower heat flux to the next-level cooling system. Since radar systems are compromised of many heat sources that must be strategically placed for functionality, it’s often better to transfer heat to a common location for a liquid-cooled system to then collect and transfer the heat to the ultimate heat sink. These heat sources can often have high-heat flux and it’s paramount to have a solution that will operate with low delta T when moving heat from a source to a liquid loop. Heat pipes also offer high reliability and can be integrated within rugged structures to allow for harsh environment operation without degradation.

Thermally, the two-phase devices offer highly effective heat transfer by operating in a closed loop and leveraging the latent heat of vaporization of the fluid; at the evaporator, the heat enters and vaporizes the fluid, which pushes the fluid vapor to the cooler portion of the device. This point, known as the condenser, is coupled with a heatsink, in the case of radar electronics, a liquid loop. The fluid gives up its latent heat at the condenser and is pushed back to the evaporator via capillary action provided by an internal wick structure. Overall, implementing a passive two-phase device will provide better control of high heat flux and lower temperature rise from source to sink without any energy consumption or reliability concerns.

What Are Liquid Cooling Systems?

In large-scale radar systems, liquid cooling is a necessity due to the total heat load (10s to 100s of kWs). Single-phase Liquid cooling solutions often use a mixture of water and propylene or ethylene glycol. When combined, this fluid helps reduce freezing and protects against corrosion. The system runs the fluid around the heat-producing components and keeps their temperature at acceptable levels. There are many options for pumps and cold plates available and the complexity is typically dictated by the system architecture and component layout.

Additional items that are critical to the overall performance include:

  • Liquid-to-air systems: After the heat is collected by the cold plates, the liquid loop will route heat to a volume suitable to dissipate to air. At this location, a Liquid-To-Air (LTA) heat exchangers, typically tubing routed within fin stock (coils) will reject the heat. These systems provide significant surface area and sufficient conduction paths to allow for efficient heat dissipation.
  • Chiller systems: Chillers use a vapor-compression cycle to provide liquid chilled below the ambient temperature.

These systems are versatile solutions, fitting various military radar applications. You can use liquid cooling systems in stationary positions and mobile units when military personnel moves through different territories.

What is Pumped Two-Phase Cooling?

Pumped two-phase (P2P) cooling is a higher-performing method of liquid cooling for systems requiring a high degree of temperature uniformity, systems that must operate at low energy consumption or systems with high heat flux requirements. P2P systems remove heat from high-powered heat sources like radar electronics by flowing fluid across heat sources and boiling in order to operate in both liquid and vapor phase  The two-phase fluid then flows to a condenser, Typically an air-cooled heatsink or vehicle radiator to reject the heat. An accumulator is used to balance the system and provide single-phase fluid to the pump. Pumped two-phase systems can run on a continuous cycle, constantly working to remove heat.

Two-phase pumped cooling systems are designed for highly efficient heat transfer across small and large distances, making them excellent options for medium to large scale radar technology. Other benefits of two-phase cooling systems include the following:

  • Reduced size, weight and power: These systems have lower flow rates and require significantly smaller pumps providing packaging advantages and lower overall mass and energy consumption.
  • Temperature isothermality: As the fluid is pumped through the system, the heat is absorbed in the latent heat of the fluid, adjusting the quality (liquid-to-vapor ratio), with minimal temperature rise. Whereas a single-phase liquid would have gradients across large distances with multiple heat sources, Pumped Two-Phase systems operate with very low-temperature differences.

Choose Advanced Cooling Technologies Liquid Cooler and Chiller Systems

Image shows chiller system. Text reads: Choose Advanced Cooling Technologies Liquid Cooler and Chiller Systmes.

Cooling solutions are essential for military personnel and equipment. If you need military radar cooling systems, choose Advanced Cooling Technologies. Since 2003, ACT has provided thermal management solutions for everything from commercial satellites to medical devices. As a leading thermal management solutions manufacturer, ACT provides high-quality and thorough systems for a wide range of industries.

ACT offers a line of rugged cooling systems that are excellent for military radar applications. ACT’s Tekgard® brand can meet intense workloads and remain reliable in harsh conditions. It features advanced liquid cooling technology that can keep radar electronics working at their full potential. You need high-powered and dependable systems to complete field missions and protect teams, and these systems can deliver.

To get started with ACT cooling systems, contact us today.


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