JED - January 2018 - 24





The Journal of Electronic Defense | January 2018

Figure 2: Notional advanced collaborative EW scenario where two craft send RF jamming signals to a distant target. Each jamming signal can be
modeled as a segment of a plane wave, and the signals arrive from different directions. We can orient either the electric fields or the magnetic fields
to a common polarization, but not both.

Maxwell's Equations. Like any differential equations, these laws have general solutions and particular solutions
where any constraints, coefficients,
and boundary conditions determine the
particular solution. The particular solutions to these equations are limited
only by the imagination of designers
in selecting materials and specifying a
layout. Left-handed metamaterials are
a classic example where innovative arrangements of right-handed materials
result in left-handed behavior. Essentially "all things are possible" when it
comes to this first category.
The second category includes all of
the conservation laws, and this category is completely different. Conservation laws are absolute, and collaborative
EW is subject to conservation of energy
just like anything else. And so, the total power delivered to a target by a collaborative EW system can never exceed
the total power transmitted by all of the

jammers that make up the system. For a
set of N equal power emitters, operating
coherently, it can never be true under
any circumstances that "(t)he power at
the target position is expected to approach N2 for N transmitters or arrays."1
And websites that seem to be too good
to be true in promising "free energy"
from wave fields are exactly that - too
good to be true.

Linear superposition is a fundamental property of all linear systems
including Maxwell's Equations. For collaborative EW, the EM field generated
through collaboration is just the sum
of the individual fields generated by
the different jammers. But, what does
that field look like, and how much power does it carry? Here is where things
start to get complicated and there are
no short cuts.

Suppose we have multiple jammers,
each generating separate EM fields
(propagating waves) directed towards a
distant target. Because we have linear
superposition of multiple EM waves, one
might at first glance expect the linear
sum just to be a bigger EM wave - and
that would be wrong. The only time that
EM waves add together to make a bigger (or smaller) wave is when they are
exactly aligned in all three dimensions.
The individual electric fields must have
exactly the same polarization and the
individual magnetic fields must have
exactly the same polarization such that
all of the power flows are along exactly
the same direction whether positive or
negative. For this special case - and
only for this special case - is the resulting EM field a bigger (or smaller) wave.
For any other case, no matter how slight
the difference, the resulting EM field
will be some sort of interference pattern
with electric and magnetic field intensi-


JED - January 2018

Table of Contents for the Digital Edition of JED - January 2018

The View From Here
Conferences Calendar
Courses Calendar
From the President
The Monitor
Washington Report
World Report
Thinking Through Collaborative Electronic Warfare
Report from the 6th Annual AOC Pacific Conference
EW 101
AOC News
Highlights from the AOC 54th Annual International Symposium & Convention
Index of Advertisers
JED Quick Look
JED - January 2018 - Intro
JED - January 2018 - cover1
JED - January 2018 - cover2
JED - January 2018 - 3
JED - January 2018 - 4
JED - January 2018 - 5
JED - January 2018 - The View From Here
JED - January 2018 - insert1
JED - January 2018 - insert2
JED - January 2018 - 7
JED - January 2018 - Conferences Calendar
JED - January 2018 - 9
JED - January 2018 - Courses Calendar
JED - January 2018 - 11
JED - January 2018 - From the President
JED - January 2018 - 13
JED - January 2018 - 14
JED - January 2018 - The Monitor
JED - January 2018 - 16
JED - January 2018 - 17
JED - January 2018 - 18
JED - January 2018 - 19
JED - January 2018 - Washington Report
JED - January 2018 - World Report
JED - January 2018 - Thinking Through Collaborative Electronic Warfare
JED - January 2018 - 23
JED - January 2018 - 24
JED - January 2018 - 25
JED - January 2018 - 26
JED - January 2018 - 27
JED - January 2018 - 28
JED - January 2018 - Report from the 6th Annual AOC Pacific Conference
JED - January 2018 - 30
JED - January 2018 - EW 101
JED - January 2018 - 32
JED - January 2018 - AOC News
JED - January 2018 - Highlights from the AOC 54th Annual International Symposium & Convention
JED - January 2018 - 35
JED - January 2018 - 36
JED - January 2018 - Index of Advertisers
JED - January 2018 - JED Quick Look
JED - January 2018 - cover3
JED - January 2018 - cover4