This document describes a new microwave life detection system that can locate humans buried under earthquake rubble by detecting their breathing and heartbeats remotely. It works by sending microwaves through rubble at 1150MHz and analyzing the reflected signal for modulations caused by vital signs. A dual antenna system switches between antennas 100 times per second to eliminate clutter. A clutter cancellation circuit removes rubble reflections to isolate the human signal being picked up. This system aims to decrease earthquake death tolls by aiding rescue of survivors trapped in debris.

1. Presented by
SNEHA

2. INTRODUCTION
Thousands of persons killed as a cause of earthquake. A
new revolutionary microwave life detection system,
which is used to locate human beings buried under
earthquake rubble, has been designed. This system
operating at certain frequency can remotely detect the
breathing and heartbeat signals of human beings buried
under earthquake rubble. By advent of this system the
world death rate may decrease to greater extent as large
percentage of death occur due to earthquake.

3. RECENT NEWS
Strong Earthquake hits JAPAN and more than 500
people have died in an eathquake under the rubble’s.
The disaster in the new york’s city at Woorld Trade
Center claimed lives of more than 5000 people.

4. MICROWAVES

6. Microwaves are electromagnetic waves
whose frequencies range from about 300
MHz-300 GHz or wavelengths in air ranging
from 100cm-1mm.
The word microwave means a very short
wave, which is the shortest wavelength
region of the radio spectrum and a part of the
electromagnetic spectrum

10. The reception of
modulated
signals shows the
presence of a live
human inside
the rubble.
When the beam
hits the body, the
signal reflected
with an
additional
modulation
created by
movements of
heart and lungs
Microwave
would reflect
back from some
objects.
Microwave is sent
through rubble to
detect vital signs
of life.

11. LAPTOP
DUAL ANTENNA
CLUTTER
CANCELLATION
MICROWAVE
CIRCUIT

13. MICROWAVE CIRCUIT
Microwave
circuit
Phase
locked
oscillator
Direction
al coupler
circulator
•The PLO is used to generate a very
stable EM wave of 1150 MHz
•Power dividers and directional
couplers, coupler part of the
transmission power in a transmission
line by a known amount out through
another port.
•In this system, 10db coupler is used
to divide the power into 1/10th and
9/10th part while 3db coupler divides
power into two equal parts.

14. The dual antenna system has two antenna, which
are energized sequentially by an electronically
controlled microwave single pole double throw (
SPDT) switch.
The switch turns on and off at a frequency of 100
Hz which is much higher than the frequency
range of the breathing and heartbeat signals
between 0.2 to 3 Hz.
In this dual antenna system, the two antenna
channels are completely independent.

16. The clutter cancellation circuit consists of a digitally controlled
phase-shifter (0–360 ), a fixed attenuator (4 dB), a RF amplifier (20
dB), and a digitally controlled attenuator (0–30 dB). The output of
the clutter cancellation circuit is automatically adjusted to be of
equal amplitude and opposite phase as that of the clutter from the
rubble. Thus, when the output of the clutter cancellation circuit is
combined with the received signal from the antenna, via the
circulator, in a 3-dB directional coupler, the large clutter from the
rubble is completely canceled, and the output of the 3-dB
directional coupler consists only of the small reflected wave from
the subjects body. This output of the 3-dB directional coupler is
passed through a 6-dB directional coupler. The 1/4 of this output is
amplified by a RF preamplifier (30 dB) and then mixed with a local
reference signal in a double-balanced mixer. The other 3/4 of the
output is detected by a microwave detector to provide a dc voltage,
which serves as the indicator for the degree of the clutter
cancellation. When the settings of the digitally controlled phase-
shifter and attenuator are swept by the microprocessor control
system, the output of the microwave detector varies accordingly.

17. •Power tool in applications where it is not
desirable to disturb a subjects physiological
or in other situations where access to the
subject is limited.
•L-band frequency free for use by
commercial applications so far we expect a
minimum interference with other devices.
•No need to use heartbeat and the breathing
sensor.

18. •Project is expensive but once it is implemented
the expenses can be reduce lower extend
•The UHF band frequency is unable to penetrate
more metal like structure but it can penetrate
over deeper than 1150 MHz
•The involvement of clutter signal may destroy
the vital information of life signs. But if the
proper demodulation is used one can receive the
vital signs efficiently.