08-10-2025, 04:50 PM
Quantum Radar: What It Is and Why Everyone Keeps Talking About It
![[Image: quantum.jpg]](https://denyignorance.com/uploader/images/quantum.jpg)
You have probably seen headlines claiming quantum radar can make stealth jets useless or that China already has one that works out to 100 km. Most of those headlines leave you with more questions than answers. Here is the plain-language version without the hype.
What is quantum radar?
Instead of sending out a normal radio wave pulse and waiting for the echo, quantum radar uses a trick from quantum mechanics called entanglement. You make pairs of “linked” photons, or sometimes microwave photons. One photon in the pair, called the signal photon, is sent toward the target. The other, called the idler photon, stays in your radar system.
If the signal photon bounces back, the radar compares it to its idler twin. Because they were created together, they share unique traits such as polarization and phase. If those match up, you can tell it is a real return and not just background noise.
Why does that matter?
Stealth works by scattering and absorbing radar energy so very little comes back to the receiver. Quantum radar’s big promise is that even a handful of matching photons could stand out from the noise floor. In theory, that means you could detect things normal radar would miss.
The advantages on paper:
Entanglement is fragile. The second those photons go through the atmosphere, hit a moving aircraft, and bounce back, their quantum link is almost always lost. At this stage, the real-world range for true entangled-photon radar experiments is measured in meters, not kilometers.
About that Chinese 100 km claim:
In 2016, China’s CETC said they had a working 100 km quantum radar. No independent proof has ever surfaced. Most experts believe they were either using a different “quantum-inspired” signal processing trick or doing a bit of psychological warfare to influence other militaries.
(This is a good place to link to another thread concerning China making technical breakthrough claims in hopes that the US will research it so China can in turn steal it - Is China Tricking The Pentagon?)
Where it stands now:
Quantum radar is still a laboratory project for the most part. The United States, Canada, and Europe are working on it, but nobody has fielded a system that can track a stealth jet in combat conditions. The physics is possible, but the engineering is extremely challenging.
So, if you hear someone say quantum radar makes stealth useless, take it with a grain of salt. We will know it is real long before any press release because it would change how stealth aircraft operate almost overnight, and those changes would be impossible to hide.
You have probably seen headlines claiming quantum radar can make stealth jets useless or that China already has one that works out to 100 km. Most of those headlines leave you with more questions than answers. Here is the plain-language version without the hype.
What is quantum radar?
Instead of sending out a normal radio wave pulse and waiting for the echo, quantum radar uses a trick from quantum mechanics called entanglement. You make pairs of “linked” photons, or sometimes microwave photons. One photon in the pair, called the signal photon, is sent toward the target. The other, called the idler photon, stays in your radar system.
If the signal photon bounces back, the radar compares it to its idler twin. Because they were created together, they share unique traits such as polarization and phase. If those match up, you can tell it is a real return and not just background noise.
Why does that matter?
Stealth works by scattering and absorbing radar energy so very little comes back to the receiver. Quantum radar’s big promise is that even a handful of matching photons could stand out from the noise floor. In theory, that means you could detect things normal radar would miss.
The advantages on paper:
- Better noise rejection, so you can run at very low power without giving away your location.
- Potential to see low radar cross-section targets such as stealth aircraft.
- Possible improvement in bad weather or cluttered environments.
Entanglement is fragile. The second those photons go through the atmosphere, hit a moving aircraft, and bounce back, their quantum link is almost always lost. At this stage, the real-world range for true entangled-photon radar experiments is measured in meters, not kilometers.
About that Chinese 100 km claim:
In 2016, China’s CETC said they had a working 100 km quantum radar. No independent proof has ever surfaced. Most experts believe they were either using a different “quantum-inspired” signal processing trick or doing a bit of psychological warfare to influence other militaries.
(This is a good place to link to another thread concerning China making technical breakthrough claims in hopes that the US will research it so China can in turn steal it - Is China Tricking The Pentagon?)
Where it stands now:
Quantum radar is still a laboratory project for the most part. The United States, Canada, and Europe are working on it, but nobody has fielded a system that can track a stealth jet in combat conditions. The physics is possible, but the engineering is extremely challenging.
So, if you hear someone say quantum radar makes stealth useless, take it with a grain of salt. We will know it is real long before any press release because it would change how stealth aircraft operate almost overnight, and those changes would be impossible to hide.
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