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Communication Electronics Research Group
www.comelec.itn.liu.se
2
Multiport Technology
Guiding and superposition of RF signals
In a passive component
Wave interference
Introduction
The multiport network acts as an interferometer
It guides high frequency signals (waves) through different paths so that they are superimposed
The signals interfere
The result is a “pattern” from which information about the signals can be extracted
Optical interferometry is an traditional laboratory technique used for accurate measurements
The “electrical” interferometer relies on the fact that signals at GHz-frequencies have so small wavelengths, that small path differences results in measurable phase and
amplitude differences
Communication Electronics Research Group
www.comelec.itn.liu.se
3
Multiport Technology
Microwave Passive Components
The multiport network consists of microwave passive components based on quarter-wave (λ/4) transmission lines
Example above: Quadrature coupler
Design aspects:
Designed for operation frequency, f0
They can be improved in terms of larger bandwidth
Are characterized by small deviations against theoretical phase- and amplitude-expected values
The occupied area is inversely proportional with operation frequency, f0
Quadrature coupler Wilkinson power divider
V+·ejωt
αV+·ej(ωt-90°)
αV+·ej(ωt-180°)
Communication Electronics Research Group
www.comelec.itn.liu.se
4
Multiport Technology Applications
1970’s: Accurate measurements of the complex reflection coefficients
1994: Microwave and millimeter wave radio receivers
Today:
Network analysis: Reflection coefficients, phase and frequency analysis
Data transmission: Direct modulation/demodulation at RF/MW frequencies with low-power and low-costs
Radar, automotive: Distance and angle-of-arrival measurements
Radar, medical: Heartbeat and respiration rate measurements Automotive and medical
radar applications
Low-power, broadband communication systems
Multi-port Multi-port
Communication Electronics Research Group
www.comelec.itn.liu.se
5
Research at Comelec
4 2
LO
b5
Zo
a6
Z4 Z2
Z1 Z3
6
5
1 3
H 90
H 90
H 90
Zo
2
6aj
2
6a
631
22
ΓΓaj
642
22
ΓΓa
W
4 2
1 3
l
Q
16-QAM constellation diagram
of the RF modulated signal
Communication Electronics Research Group
www.comelec.itn.liu.se
6
Research at Comelec
Radio receiver – Multiport demodulator implementation
The local oscillator (LO) is connected at port 5
The received RF signal is amplified by the low-noise amplifier (LNA) and applied at port 6.
Square-low matched power detectors are connected to the output ports 1 to 4 of the circuit. The output signals are linear phase shifted combination of inputs
Two differential amplifiers are used to obtain the quadrature I- and Q-signals
The circuit can operated either in direct conversion or low intermediate frequency (IF) schemes
b4
LOa5
Zo
a6
6
5
1 3
4 2
+
-I
-
+
Q
b3
b1
b2
H 90
H 90
H 90
W
LNA
Communication Electronics Research Group
www.comelec.itn.liu.se
7
Research at Comelec
Pros of the Multiport Technology
The main advantage is the reduced LO
power to operate in both Tx- and Rx-mode
Broadband operation, hence high data rate
High linearity
Very accurate phase difference detector
Integrability with other high performance RF components
Low-cost
Short time from design to prototype
6 14
5 32
Multiport modulator
with ROGER 4350B Constellation of the RF signal
400 Mbit/s 1.2 Gbit/s
Cons of the Multiport Technology
Relatively low-sensitivity
Large dimensions at lower frequencies
Multiport technology is a flexible but unitary RF/MW technology for:
High-data rate data transmission with low-power consumption
Network analysis
Localization purposes
Distance measurements
Angle-of-arrival (AoA) measurements
Vibration analysis based on ultra-high resolution measurements (one-digit
micrometer or nanometer range)
Contact person: Adriana Serban
Communication Electronics Research Group
www.comelec.itn.liu.se
11
Sensors, actuators, RFID, robots……
Internet(HTTP, E-mail…)
Internet of Things
Wireless technologies:3G/4G, WiFi, Bluetooth,ZigBee, 6-LoWPAN…
Wireless sensor networks
Wireless InternetWeb of Things
Communication Electronics Research Group
www.comelec.itn.liu.se
12
Communication Electronics Research Group
www.comelec.itn.liu.se
13
Communication Electronics Research Group
www.comelec.itn.liu.se
14
Around 30 deployment sites and 11 sensors + radio transmitters per site
Vasa museum
Linköping Cathedral
Swimming house in Norrköping
University Hospital in Uppsala
Heritage house on Gotland
……………………
Communication Electronics Research Group
www.comelec.itn.liu.se
15
Wirelesss sensor networks
Kit 3 Kit 2
Kit 1
Kit 4
Communication Electronics Research Group
www.comelec.itn.liu.se
16
Sensor/Tag-1
Routers
R2
R1
R3
R4
R5
R6
Reader
User
Sensor/Tag-2
Radio
R3
World-leading IOT technology with cloud service
Proven in the Church/Museum and Hospital environments
Flexible for third-party cooperation
Long radio range with mesh network
Low power consumption (10 year battery lifetime with 15-min sampling interval)
Secure solution with encryption (AES128)
Robust system: measured data is saved in sensor modules first and then
forwarded to the local server and finally the web server
Low cost
Contact person: Shaofang Gong, [email protected]