Tri-Band RF Jamming System
Team: Sadeq AlKhalifah – Mohammad AL-Khulaif – Ali Al-Turaifi
Advisor: Dr. Oualid Hammi
Objectives
Design Methodology
Noise Generator
One of the splitter outputs represents the noise signal
that is ready for transmission in the 900 MHz band.
The designed RF jammer consists of mainly two parts: a
Noise generator is based on the noise generated by the
The remaining two signals are modulated to their
low frequency noise generator, and an RF front end.
Zener breakdown phenomenon. The circuit of the noise
targeted carrier frequencies (1.8 GHz and 2.4 GHz).
The noise source generates a low frequency random
generator where the zener diode is reversely connected
The three RF signals are then combined and fed to the
which
noise. In the RF front end part, the noise signal is
to 14V-DC source from one terminal and the other
antenna for transmitting.
can jam RF communication signals transmitted by
amplified and up-converted to each of the three
terminal is connected to a 100 kΩ resistor and a 720 pF
base stations in the 900MHz, 1800MHz and
frequency bands which they 900MHz, 1800MHz and 2.4
capacitor where the output is taken from. After
2400MHz frequency bands as three frequency
GHz. The three noise signals centered in the middle of
constructing the noise circuit and measuring its spectrum
The tests and power measurements were done using
using a spectrum analyzer, it was found that it has a
a
bandwidth of almost 60MHz centered at approximately
Analyzer N901A) . These measurements were taken at
50MHz with a power of -75dBm.
four stages: before and after the amplification stage,
 Defining the RF jamming system and showing the
importance and need of using it in many places.
 Giving a complete RF jamming system design
based on commercial of the shelf circuit
bands used in Saudi Arabia for mobile & wireless.
 Implementation
and
testing
the
design
by
the targeted frequency bands are then combined and
sent through a multi-band antenna.
using :
Testing
computerized
spectrum
analyzer
(EXA
Signal
and right after each up-converting stages. Then, the
- Advanced Design System Software ADS.
readings have been compared to the estimated ones
- Available components (hardware).
by the ADS. Finally, the project has successfully
 If time permits, improving the project to satisfy low
jammed the three targeted bands.
cost and low power consumption.
Introduction
Radio frequency (RF) Jamming System
ADS Simulation
refer to a set of radio frequency equipments that
RF Front-End
produce a RF signal to disturb a targeted
communication
In this stage four amplifiers of the Two types of ZFL-
established. This can be applied for instance for
1000LN+ and the ZX60-3018G+ were used, each has a
cell
The Tri-Band RF Jamming System that can jam RF
gain of 23 dB and 22 dB respectively which result in a
Jamming results in blocking the signal from the
GSM signals at 900 MHz and 1800 MHZ, and Wi-Fi
gain of around 90 dB in low frequency.
signal at frequency 2.4 GHz can be designed based on
receiver point view that would be no service to
Frequency up-conversion
commercial of-the-shelf components.. This system can
The up-converting was done in two stages. In the first
be achieved by building a noise generator produces
stage, the amplified noise signal obtained at the output
noise with low frequency and a known power level.
of the amplification stage is modulated to the center
Then to amplify this noise to an amount of power
frequency of 920MHz. In the second stage, takes the
more than the power of the aimed signals and up-
amplified and modulated noise generated at the output
converted to their frequency and transmitted using an
of the first up-conversion stage is fed into a 3-way
antenna.
or
prevent
other
it
wireless
from
Conclusion
being
phone
and
Amplification stage:
applications.
cell phone and wireless networks within the
effective radius of the jammer.
Cell phones work by communicating with a
service network through the utilization of cellular
towers or base stations. In Saudi Arabia,
wireless communication providers use the 900
MHz and 1800 MHz frequency bands for mobile
communications, where as (Wi-Fi) signals are in
the 2400MHz frequency band. These three bans
are the targeted ones.
Advanced Design System (ADS) is the used software
in this project. The simulation schematic is presented
for the 900 MHz, and for the two band which are
1800MHz and 2.4GHz. The noise source was replaced
by
a
single-tone
(continuous
wave)
generator
providing a signal at the center frequency of the noise
splitter.
Future Work
source’s output signal and with the same power level
The design should be improved by adding more
(-75 dBm). The various components of the front-end
applicable amplifiers to reach a higher power levels
(such as amplifiers, mixers, combiners, etc…) were
that enables the system to increase its coverage area,
simulated using their parameters available in the
because the further the noise signal from the antenna
datasheet.
the weaker it became due to the high loss of air.