Jeremy Hong: Weaponizing The Radio Spectrum

Jeremy Hong knows a secret or two about things you shouldn’t do with radio frequency (RF), but he’s not sharing.

That seems an odd foundation upon which to build one’s 2018 Hackaday Superconference talk, but it’s for good reason. Jeremy knows how to do things like build GPS and radar jammers, which are federal crimes. Even he hasn’t put his knowledge to practical use, having built only devices that never actually emitted any RF.

So what does one talk about when circumspection is the order of the day? As it turns out, quite a lot. Jeremy focused on how the military leverages the power of radio frequency jamming to turn the tables on enemies, and how civilian police forces are fielding electronic countermeasures as well. It’s interesting stuff, and Jeremy proved to be an engaging guide on a whirlwind tour into the world of electronic warfare.

SDRs Take Wing

Jeremy comes to this field more as an informed enthusiast than as an employee or contractor for one of the many alphabet agencies or defense contractors who jealously guard such secrets. A recent EE grad from Wright State University, where courses on electronic warfare (EW) are offered, Jeremy not only developed an interest in the field but has been able to observe some of the systems in action, thanks to nearby Wright-Patterson Air Force Base.

A US Navy EA-18G Growler on carrier approach.

After the obligatory “Don’t try this at home” warnings, Jeremy gave a brief history of electronic warfare, stretching back to what was possibly the first electronic war — the American Civil War — where the telegraph played a sometimes decisive role. Ever since then, both intercepting and jamming enemy signals has become immensely important and ever more sophisticated as the technology of communications and reconnaissance have developed. What was once accomplished simply by taking an ax to a telegraph pole now takes an in-depth understanding of Maxwell’s equations.

Where all this technology has led is to tools and weapon systems that are as fascinating as they are deadly. Chief among these is the EA-18G, an aerial EW platform based on the F/A-18F Super Hornet multirole combat jet. Built to not only jam enemy signals but to seek out and kill their sources, the “Growler” devotes much of its internal space to avionics bays that drive its 66 antennas, turning it in a flying “software defined radio on steroids” and the only EW system yet to score an electronic kill on the F-22 Raptor stealth fighter.

Electronic Warfare Comes Home

During Jeremy’s talk, it became clear that modern military aircraft are becoming flying nodes of immensely complex and capable networks, sharing information and synthesizing a picture of a dynamic and rapidly changing battlefield. The assets devoted to EW have remarkable capabilities, from active jamming of enemy signals with powerful transmitters to detecting enemy radar sites and launching missiles that ride the signal beam to destroy the antenna. Some EW systems are even capable of simulating the radar signatures of other planes to confuse the enemy.

EW technology is not just for the battlefield, of course. Civilians have been fighting back against law enforcement speed traps for decades with radar detectors; in turn police agencies are now using radar detector detectors to find scofflaws in jurisdictions where these devices are prohibited. And of course, in a predictable escalation in the war on speeding tickets, radar detector detector detectors are now a thing, allowing users to shut off their early-warning system before being caught using it. And despite being highly illegal, GPS jammers are also common on the road, particularly with truckers who feel the need to cheat on their electronic logging systems and perhaps mask their whereabouts from their employers.

The takehome message in all this is, if you build something that uses RF technology, someone somewhere knows how to deny it the ability to work as intended. Whether that’s a good thing or a bad thing depends on your point of view, but there’s no denying that the whole field of electronic warfare is technologically fascinating, nor is there any doubt that Jeremy wants to be at the forefront of this exciting field.

50 thoughts on “Jeremy Hong: Weaponizing The Radio Spectrum

    1. Even better: detect the radar transmission, frequency shift it lower to compensate for the doppler shift, then lower by the same amount again, amplify and re-transmit, swamping the reflected signal and indicating a speed of 0 mph.

      You might actually get away with it once.

      1. I’ve never understood the efforts people put into avoiding speed traps. It’s like a teenager who after being told they can’t have a party trashes their own bedroom. If the same effort were put into automatic cruise control that tracks the speed limit the benefit to the driver and road safety would be immensely higher.

        1. I think they lead crappy lives and suddenly feel “empowered” behind the wheel of a 2 ton steel machine. Throw in the ego centric nature of most people (me-me-me, F everyone else!) attitude, and it’s suddenly a “rush” to drive like a maniac and risk life/limb (of everyone around them).

        2. On the surface, that seems reasonable, except that speed limits are often set by those who are in a position to enforce (and profit from) them.

          Just as one example, take El Camino Real between San Jose and San Francisco. For the most part (there are a couple of small exceptions) the essential character of the road is unchanged – a divided 6 lane road with stoplights. And yet, the speed limit can be counted upon to change at every change in jurisdiction and be anywhere from 25 to 45 mi/hr.


          Because someone in power says so.

          It’s spinach. To hell with it.

          1. Frequently changes is speed limit aren’t because of changes in the road but changes in what’s next to the road. Many states use population density on top of road characteristics to set speed limits. There are, as you say, jurisdictions that do abuse their power to set speed limits in order to increase revenue.

          2. This is always annoying.
            We have traffic studies done and there are sections of road where traffic engineers say the limit should be 60km/hr.
            Council does not want to change it from 50km/hr.

            When the experts say that the speed limit is wrong and causes undue traffic and accidents, but council does not want to change it, and there are regular speed traps creating thousands of tickets a day, it seems to be politically motivated to me.

        3. Or one could show some common courtesy and do the following two things: stay in the lane that is flowing at the speed you want to drive and if someone is going faster than you move to the right as soon as you can.

        4. doubt that speed and road safety does not relate except the slow drivers are in the way of people who actually have something important going on. they use cameras in my area, they are advanced now also. used to be able to use a spray that would leave a raised clear layer which caused the flash to reflect the image. i have heard of infrared light being used to deflect the image. i could care either way i have president level window tint so i just request a court hearing if you cant identify the driver you cant charge me!!1

          1. Lot of people don’t drive fast, just for fun, sometimes driving is their job. If you get held up in traffic, or get stuck on a scenic detour, there is some need to make up for lost time. Really depends on the type of job, and how you get paid for it. Could be making your delivery on time, could be the number of trips you make, miles you drive., paid by the load. Of course, you can earn less money, disappoint your employer or customers, and just drive the speed limit, but could also cost you your job, and the reason sometimes follows you, as you try to find similar work.

            I speed, sometimes for need, but mostly because traffic a road conditions allow for it. I’m not aggressive about it, I don’t pass people doing the speed limit, I won’t get aggressive, mostly go with the flow, or try to keep a comfort zone. I don’t like cars driving next to me, on a two lane road, when there is plenty of road, to leave space. Seems really odd to me, we don’t generally ‘tail-gate’ others, or like it when someone is riding ours, yet many think staying parallel is just fine. I like the room, incase there is something in the road, I have the option to swerve, without leaving the road, or slamming on the brakes.

        5. “It’s like a teenager who after being told they can’t have a party trashes their own bedroom.”

          id argue that it is more like a person who uses an accountant to find loopholes in the tax law. A lot of speed traps are revenue generation for the relevant police forces, a tax on speeders, and we all know that time is money so speeders are just people who like to make money! Which often happens at the expense of everyone else’s safety and health.

      2. Even better: How about everyone just obey the law ? (speed limit).

        If not, then remove the speed limits completely.
        Let anarchy rule the highways !
        Mad Max in real life.
        All for it, Darwin Awards await.
        We don’t need to stinkin’ speed limits !

        1. Actually, we don’t need speed limits. We already have the primary speed law, which states that it is unlawful to drive at a speed which is unreasonable or imprudent for local conditions. That’s enough.

          1. German here: it’s not, because “unreasonable or imprudent for local conditions” is way too ambiguous in court. Our police had major problems on the Autobahn stretches with no speed limits, in the end they had to settle on a de-facto unspoken speed limit which was so high that there was no doubt that it was reckless. Which was 220 km/h in most cases. Way too much, even if we are used to drive 180 km/h. Now most Autobahns have a 120 km/h limit and it’s a much better and safer solution.

          2. Yeah, however there are a lot of dumb over confident “drivers” that feel it’s there right to do what ever they feel they can do, regardless of conditions. In the northern states, I tell every one you may have 4 wheel drive, you don’t have 4 wheel stop on slick roads.

          3. Let’s look at a split timeline: 1) Drive fast. Time X: Crash because of too fast. Trial is short: You crashed because of too fast, you are to blame, because you were only allowed to drive slower than too fast. Problem. the “facto” in “post-facto” can be a lot of dead people that were not driving too fast, or even driving at all. 2) Drive fast. Time X-1: Police stops you because too fast. You say ‘but officer, i did not crash, how do you know it was too fast?’

          1. Accidents on the autobahn are actually not all that uncommon. Unlimited speed sections of the autobahn are getting to be few and far between however and most accident happen because of fuckwits not paying attention (as they do everywhere). Driving in Germany nowadays mostly involves creeping along “Baustelle” however. The free unlimited Autobahn of mythology doesn’t actually exist as such anymore

      3. I recall a construction article in 73 amateur radio magazine, for a passive means of altering the frequency of the reflected signal. I pass on that, because with my luck it would go the other way, and register a speed that would result in my need to post bail.

      4. People have designed and built jammers of that sort for years. I heard a story once that someone forgot to reset the target speed from 55 to 35 and got a ticket when he *wasn’t* speeding. Hoist on his own petard.

        And, no, this wasn’t me.

      1. 1. How does a detector create harmful interference?

        2. Most of the radar bands are co-secondary. I could make just as valid an argument (if I were transmitting) that the cop’s radar gun is interfering with me.

  1. A HERF (High Energy Radio Frequency) gun would be interesting. Consider a mobile Tesla coil or Van deGraff mounted to a vehicle. Or, better yet, run a line from your ignition circuit to a coil outside of your car. If only we could get some Gunn Diodes and build our own detector / deflectors. *sigh* EMF is such a “Broad Spectrum” of energy. Okay, time for me to take my meds. Very good read as always.

    1. Technically, I’m thinking the work around countermeasure would be a passive system considering materials science that maybe the absorbing/transmitting/reflective/diffusing/refracting materials would change the emission characteristics of the target. Then there is no threat of transmitting outside of ISM or legal methods regs.

      Interesting is the other use of lasers and radar as another recent HaD article notes lasers used as a microphone or for measuring… a radar can be used the same also:

      1. Here is something that some can consider in regards to if they’re denying the capabilities of coercion, manipulation, seduction, intimidation, blackmail and extortion from the subliminal programming that is not required for survival and leads on fantasy, delusion, brain damaged thought and are ways to cause a mild traumatic brain injury that can in fact be perceived as an intentional assault by a false pretense (masked) armed robber to cause serious bodily harm on the mental facilities if not at least mild bodily harm on the mental facilities.

        Cancer and mutations one thing along with impaired fertility data that has been shown.

        Cult programming, brain washing and mind control can lead whole population to not believe the truth and follow the pide piper to a suicidal death in fact from the Mann Act violations by the invasive nuisances that are an imminent threat.

        The remote sensing tech that can even be made with modified radio and RADAR equipment when used to transmit can project sound like a speaker and isn’t undisclosed. This effect can be performed using lasers also. Here is some data relating to the Active Denial frequency range of ~95GHz and regular WiFi that most of us are more familiar with.

        Here is how they perform electronic heroin to cause amnesic effects source info:

        From the noted programming above from remote sensing and transmission stations that are highly unlawful… coupled with the public servant systems including the educational systems and others like court, law enforcement and attorney rackets acting like we can’t Pro-Se defend and don’t require law studies in elementary and grade school… these malicious destruction of personality and property that are intent and hell bent on assaulting with intent to maim, murder and serial kill in slow kill ways and means using forensically clean natural cause of death methods (think about how many don’t have an autopsy performed and are cremated even when requested also or required when there is reasonable suspicion… then all the excuses that are invalid like costs then why do they have a job… they blatantly make their job metrics fail since they’re no way lean or six sigma or even valid in general. Invalidated system in fact that needs to be fire squad killed off immediately that behaves cruel and unusual) are going to invasive nuisance do what they want. Not bad if law abiding citizens and systems in fact. Most deny the truth, make false pretense statement, blatantly cause homicide, perjure or allow perjury and worse unlawful acts to be committed by their network to compound and conceal the truth criminally.

        This really isn’t new technology. Just new hardware systems that can target different human body and a larger range of human body sympathetic resonance frequencies like a spectrometer or spectrum analyzer can sense to cause more remote sensing with remote injury, maiming, murdering and unreasonable serial killing effects… at least until all that is left is their liberal pan troglodyte bonobos or worse hair pin, brain damage, hit on the head, not capable of logical valid honest sincere truthful pro life thinking. Incest pedophile homo junkies at their best.

  2. In my part of the world, radar speed traps are no longer legal for use.
    This happened after an electronics prof became an expert witness for the defense and proved that radar was unreliable in this application.
    They only use laser now. And by the time your laser detector has picked it up you have already been caught for speeding

      1. It was in the early 2000’s . I could not find any info on it. But I recall at the time that testing showed that stones flying from tyres, wind screen wipers working and other cars close by could all affect the speed. A proffesor from a local university was the expert witness for the defense. After the state losing many cases they switched to other methods such as tubes and coax across the road to trigger the systen. Those methods were then also discredited and now they only user laser, detectors under the road or video average speed detection over a couple of Km’s

  3. I find it funny that some trucks must use a device to jam GPS, I just used a steel bucket over the satcom antenna, not to willfully cheat logs, but only to hide so I wouldn’t be asked to cheat logs.

    1. I like to watch an hour or two of Dash-Cam on Youtube before a trip. It tunes me in on the unexpected I should really be expecting. I look for US videos since the Russian videos have an excessive amount of flying tires, rear suspensions popping out of trucks, loss of steering control, untrained big rig drivers, and cars that roll over like in Mr. Bean.

  4. Firstly in answere to why radar was proven unreliable for speeding fines.
    The width of the beam allowed it to be reflected off any metal surface to parked cars cars in the opposite direction, or that car that just overtook you. The delay piggy backed itself on the follow up
    Presenting a distorted number usually higher. This is known as the DOPPLER-EFFECT.
    Weaponizing the airwaves already under way 5 g presents an algorithm that interacts with electrical frequencies inside your head, once broken, you are ready for upload download.everyones frequencies fits within a narrow bandwidth.
    Reasearch was based on the Argentine Ant who use this principle enmase to destroy.
    Research your end. Yeah! I’ hoped this was Bullshit to…Sorry.

    1. My thought and observation is that the different FCC, and maybe even other countries, 5G approved frequencies when phase synchronized and combined then amplified from multiple sources beam steering and at the convergence point… addition frequency adds up to the 95GHz Active Denial system that is known to even cause permanent damage if not attenuated on the target under the lethal/maiming threshold that of course is denied and not disclosed. That 95GHz is a frequency not well disclosed regarding humans emissions from what I’ve tried to research. Like detailed EMS DC to Cosmic full range EMF data on the human body… there isn’t any resource I’ve found other than this:

  5. [in the us]
    the federal and local governments have authority to use
    RF jamming/detecting (counter)measures
    and civilians have none or extremely limited access
    it seems like there should a second amendment for
    ‘allowable’ citizen RF usage

  6. “…the F/A-18F Super Hornet…the only EW system yet to score an electronic kill on the F-22 Raptor stealth fighter.”

    I have to assume this isn’t worded correctly, and that the Growler is the only EW system to have scored an electronic kill on the F-22. If not, both the Growler and the F-22 must suck. ????

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