The "secret 3G radio" smells like BS... seriously, where the heck would they hide the antenna for this secret modem?
Anyway, this is great news. Hopefully they can find a way to permanently disable this backdoor.
With todays technology it is not a real problem to design an antenna that is way smaller than the desired 1/4 wavelength that is so common.
We use in designs all the time special ceramic chip antennas that have special dielectrics.
For example :
http://katalog.we-online.com/en/pbs/WE-MCA?sid=9ec2dee9ad
https://www.johansontechnology.com/antennas
https://product.tdk.com/info/en/products/rf/rf/antenna/index.html
https://en.wikipedia.org/wiki/Dielectric_resonator_antenna
Features
Dielectric resonator antennas offer the following attractive features:
- The dimension of a DRA is of the order of λ 0 ϵ r {\displaystyle {\frac {\lambda _{0}}{\sqrt {\epsilon _{r}}}}}
, where λ 0 {\displaystyle \lambda _{0}}
is the free-space wavelength and ϵ r {\displaystyle \epsilon _{r}}
is the dielectric constant of the resonator material. Thus, by choosing a high value of ϵ r {\displaystyle \epsilon _{r}}
( ϵ r ≈ 10 − 100 {\displaystyle \epsilon _{r}\approx 10-100}
), the size of the DRA can be significantly reduced.
- There is no inherent conductor loss in dielectric resonators. This leads to high radiation efficiency of the antenna. This feature is especially attractive for millimeter (mm)-wave antennas, where the loss in metal fabricated antennas can be high.
- DRAs offer simple coupling schemes to nearly all transmission lines used at microwave and mm-wave frequencies. This makes them suitable for integration into different planar technologies. The coupling between a DRA and the planar transmission line can be easily controlled by varying the position of the DRA with respect to the line. The performance of DRA can therefore be easily optimized experimentally.
- The operating bandwidth of a DRA can be varied over a wide range by suitably choosing resonator parameters. For example, the bandwidth of the lower order modes of a DRA can be easily varied from a fraction of a percent to about 20% or more by the suitable choice of the dielectric constant of the material and/or by strategic shaping of the DRA element.
- Use of multiple modes radiating identically has also been successfully addressed.
- Each mode of a DRA has a unique internal and associated external field distribution. Therefore, different radiation characteristics can be obtained by exciting different modes of a DRA.
It will not give you kilometers of distance but it does work , as evident by all bluetooth and wlan devices. (2,4GHz and 5GHz).
A custom designed ceramic cpu package with special dielectrics for higher microwaves may be possible.
But that is really tinfoil hat stuff and it will only give you a few meters of distance.
It is possible if one has the resources.
But in all honesty, we are not interesting enough. Not rich or extremely smart or dangerous enough.
Besides, imho everything you have ever looked up with google is scanned and when blacklisted words or phrases appear, you get another check mark added to your name.
I am sure i have quite a few check marks because of my technical curiosity.
edit :
Forgot to mention that nowadays, it is possible to make a chip that has a pll oscillator combination that can easily produce 60GHz. In a design that is just a few tens of dollars.
As evident by all the integrated radar chips(with integrated antennas) such as for example the RIC60A from omniradar.
http://www.omniradar.com/products/
You can use it with doppler radar or which is interesting for students to design :
Frequency modulated continuous wave radar.
Which has a surprising simple theory behind it to get a distance.
Great for robotics where ultrasonic might not work properly.
https://en.wikipedia.org/wiki/Continuous-wave_radar#Modulated_continuous-wave
http://www.radartutorial.eu/02.basics/Frequency Modulated Continuous Wave Radar.en.html