JED - August 2013 - 37

By Ollie Holt

Next, the survey looks at the frequency range the
receiver covers. This could be in one full look or as multiple looks (i.e., looking at a smaller segment of the total frequency coverage in discrete steps).
The instantaneous bandwidth (IBW) can be listed in
different ways, and an ELINT receiver can have multiple
IBW’s. A channelized receiver could list the input IBW
as 500 MHz and then the software/firmware can channelize the data such that within the 500 MHz multiple
smaller IBW channels can be created. The responses
contain all the different IBW’s that the listed ELINT receiver can be commanded to use.
The installed sensitivity column in the survey lists
the sensitivity that the ELINT receiver achieves at the
different IBW’s. Because sensitivity is a function of the
IBW, the receivers with wider IBW figures will be less
sensitive than the receivers with narrower IBW figures.
That is one advantage of channelized receivers – they
provide a wide IBW input that can be reduced to many
smaller IBW receivers, so the installed sensitivity is
based on the narrower IBW. This means the receiver
can look over a large frequency range at one time while
achieving the sensitivity derived by the smaller IBW
Total dynamic range defines the lowest input level
to highest input level the receiver can process without
creating spurious information. It’s basically the linear
operating range of the receiver. Signals with levels below the lowest input level will be detected, while signals
above the highest input level will be detected but will
start to create additional spurious data.
Total dynamic range and instantaneous dynamic
range can be the same or they may be different. Some
ELINT receivers may have amplifiers in the front end
– receiver components prior to the signal detection
processing – and these amplifiers may have multiple
gain levels. This gives the receiver the ability to enable or disable specific amounts of gain. The Total Dynamic Range is then the Dynamic Range achieved at
the lower end with maximum sensitivity to the top end
with minimum sensitivity. These two states can’t occur
simultaneously but they do define the ELINT receiver’s
Total Dynamic Range, while the Instantaneous Dynamic
Range is that achieved at single gain state.
Our next survey will continue to focus on SIGINT and
will cover tuners for SIGINT applications.

The Journal of Electronic Defense | August 2013


ollowing our recent survey on analog-todigital (A/D) converters, this month we are
taking a look at an application for those A/D
converters. The application in question is
electronic intelligence (ELINT) receivers. In
the survey on A/D converters some of the
responses showed that it is now possible to process signals in the digital domain, which supports signal processing techniques to recover parameters on signals
that analog receivers were never able to measure. This is
especially useful in an ELINT receiver, which is trying to
collect information on signals that can support future
emitter detection and identification.
The ELINT receiver tends to cover a larger total frequency range then the typical ESM or RWR receiver,
and they serve a slightly different purpose. The ELINT
receiver usually has an operator who can aid in the selection and analysis of the signals observed in the environment. The operator can be cued to a certain signal by
other external information or he can chose to observe
signals he or she has detected in the RF environment.
The ELINT receiver does not have the same real-time
identification and intent determination requirement of
an ESM or RWR receiver, so it can dwell on a signal for a
longer period of time, and it can collect a larger quantity
of information on a signal for operator or post-mission
analysis. ESM or RWR receiver designers can analyze this
collected data to gain insight in support of developing
better identification techniques.
Digital receiver modules have become available that
can be configured into single or multi-channel ELINT
receivers with capabilities similar or better than analog
versions. Today we can purchase multi-channel, VMEform-factor, digital receiver modules with 500 MHz to 2
GHz of instantaneous bandwidth and a Field Programmable Gate Array (FPGA) that can be programmed by the
user to perform the desired ELINT detection functions.
With the anticipated availability of even greater instantaneous bandwidth cards, all that is needed to create an
ELINT receiver is an RF tuner, along with some control
and signal processing software.
The first parameter listed in the survey is the receiver technology (analog, digital or other). Typically,
today’s ELINT receivers are digital, but they may further
be defined as a digital channelizer or maybe a digital
instantaneous frequency measurement (DIFM) receiver.


JED - August 2013

Table of Contents for the Digital Edition of JED - August 2013

The View From Here
Conferences Calendar
Courses Calendar
From The President
The Monitor
Washington Report
World Report
The Spectrum Management Challenge: Creating Order From Chaos
Technology Survey: ELINT Receivers
EW 101
AOC News
Index of Advertisers
JED Quick Look
JED - August 2013 - cover1
JED - August 2013 - cover2
JED - August 2013 - 3
JED - August 2013 - 4
JED - August 2013 - 5
JED - August 2013 - The View From Here
JED - August 2013 - 7
JED - August 2013 - Conferences Calendar
JED - August 2013 - 9
JED - August 2013 - Courses Calendar
JED - August 2013 - 11
JED - August 2013 - From The President
JED - August 2013 - 13
JED - August 2013 - Letters
JED - August 2013 - The Monitor
JED - August 2013 - 16
JED - August 2013 - 17
JED - August 2013 - 18
JED - August 2013 - 19
JED - August 2013 - 20
JED - August 2013 - 21
JED - August 2013 - Washington Report
JED - August 2013 - 23
JED - August 2013 - World Report
JED - August 2013 - 25
JED - August 2013 - 26
JED - August 2013 - 27
JED - August 2013 - The Spectrum Management Challenge: Creating Order From Chaos
JED - August 2013 - 29
JED - August 2013 - 30
JED - August 2013 - 31
JED - August 2013 - 32
JED - August 2013 - 33
JED - August 2013 - 34
JED - August 2013 - 35
JED - August 2013 - 36
JED - August 2013 - Technology Survey: ELINT Receivers
JED - August 2013 - 38
JED - August 2013 - 39
JED - August 2013 - 40
JED - August 2013 - 41
JED - August 2013 - 42
JED - August 2013 - 43
JED - August 2013 - 44
JED - August 2013 - 45
JED - August 2013 - 46
JED - August 2013 - 47
JED - August 2013 - EW 101
JED - August 2013 - 49
JED - August 2013 - 50
JED - August 2013 - AOC News
JED - August 2013 - 52
JED - August 2013 - Index of Advertisers
JED - August 2013 - JED Quick Look
JED - August 2013 - cover3
JED - August 2013 - cover4