Army Accelerates Electronic Warfare Development with Budget Boost
The Army is turbocharging its electronic warfare development with a budget boost, aiming to outpace rapid technological advancements and secure spectrum dominance. With a topline funding increase and strategic line-item consolidation, the service plans to swiftly deploy cutting-edge capabilities to the…
#ElectronicWarfare #ElectromagneticSpectrumOperations #Emso #MilitaryModernization #SpectrumDominance
Spiral antennas are funny devices. They are known for their extremely wide bandwidth, the ones shown here, are specified to operate from 2-18GHz.
They’re not meant as transmitting antennas, these critters are receive-only, used by (largely non-civilian) pilots who have those needs ☺️
Their low frequency boundary is determined by its physical size, in this case, the circumference of the small plate where you can see the fine spiral traces.
Once you cross below that boundary, the structure basically collapses electrically, seen here as a steep SWR ‘wall’ to the left side of the sweep.
At this point it’s not an antenna anymore, but something else (whatever that is 🤷🏼♂️😂)
#rfengineering #rfengineer #testandmeasurement #hamradio #hamr #antennaengineering #emso
In November 2023, I experimented with directional finding using a ‘rat race’ 4 port coupler. The coupler outputs deliver the sum and difference of the received signals from the two antennas and at the difference (‘DELTA’) output, a reasonably sharp signal ‘null’ is present exactly between the antennas.
In principal this should also be doable by comparing the RSSI (signal strength) between two completely similar receiver chains.
Using two AD8317, wideband demodulating logarithmic amplifiers and two antennas, the DC voltage on the output can be displayed on the oscilloscope (yellow and blue trace), and more importantly, the difference (‘DELTA’) between them (red trace).
Moving an RF source in front of the antennas, it’s clear that the DELTA signal drops when the source is right between them, and rises again towards the edges.
RF filtering will be needed to limit the AD8317 10GHz bandwidth 🙂
#hamradio #rohdeschwarz #testandmeasurement #rfengineering #rfengineer #emso
Analyst207
Søren Kjærsgaard