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GaNGaN RF RF New New Generations for Generations for Space TelecomSpace Telecom
Prof. Nuno Borges Carvalho Dept. Electrónica, Telecomunicações e Informática
Instituto de Telecomunicações Universidade de Aveiro
nbcarvalho@ua.pt http://www.av.it.pt/nbcarvalho
IntitutoIntituto de de TelecomunicaçõesTelecomunicações AveiroAveiro--PolePole
Prof. Nuno Borges Carvalho Dept. Electrónica, Telecomunicações e Informática
Instituto de Telecomunicações Universidade de Aveiro
nbcarvalho@ua.pt http://www.av.it.pt/nbcarvalho
--> IT Aveiro > IT Aveiro --> Radio Systems > Radio Systems
Radios Systems Characterization
and Design
Software Defined Radio Receiver Dynamic Range Increase
Software Defined Radio Transmitter Efficiency
RF-DC Converter Efficiency
Analysis of nonlinear behavior for: Power Measurements
Wireless Power Transmission
www.av.it.pt/rs/
RF PayloadsRF Payloads RF Payloads impose high value of power been delivered to earth …
nbcarvalho@ua.pt
Travelling Wave Tube Amplifiers – TWTA –Still been used intensively in space
applications …
Evolution of Evolution of RF Payload Power TransmissionRF Payload Power Transmission
TWTA
Heavy, Expensive, big sized …
GaAs
Low Power capabilities, good for low noise applications
GaN
Promissing Technology for high power and also low noise applications
Why GaN on space ?
Commercial Broadband
Satcom
(VSAT-16MBPS)
Commercial Satcom
Transmitters
(VSAT-1MBPS)
X-Band Military Radar
Commercial
Communications Base
Stations
GaN
GaAs
Si
1 10 1000.1
1.0
10.0
100.0
1 000.0
10 000.0
100 000.0
Ma
xim
um
Po
we
r (W
)
Frequency (GHz)
Power and Frequency Theoretical limits for
Si, GaAs and GaN devices
Evolution of Evolution of RF Payload Power TransmissionRF Payload Power Transmission
Introduction and motivationIntroduction and motivation » AlphaSat project and Participants
Introduction and motivationIntroduction and motivation The main objective of the project is to test GaN Technology in space, mainly European versions.
GaNGaN TechnologyTechnology o Transistor technology suplied by FBH
( Fredinand-Braun-Institut)
o Cosmic radiation immunity
o High frequency operation
o High power handling
Circuit SelectionCircuit Selection o Amplifier
Pros: Optimum for mimic future applications of GaN technology onboard of
satellites, possibility to study TWTA future changes.
Cons: High values of consumed power, need for external signal source and driver
circuit, mass increase due to several circuits need for data gathering.
o Oscillator Pros: No need for extra signal excitation sources, possibility of including all
circuitry and its measurement systems inside the same box, reduction of
power consumption and mass.
Cons: Do not excite all characteristics of the technology under study.
Selected Circuit
Oscillator CircuitOscillator Circuit o Oscillator based on traditional Colpitz configuration
o Frequency of oscillations imposed by payload restrictions (near 2GHz)
o Ceramic resonator for high Q
o Prototype should consider high frequency
oscillations due to impressive transistor quality
o Oscillations near 12-15GHz.
D1
D2
Oscillator CircuitOscillator Circuit
Stubs for high frequency spurious reduction
Measurement circuit Power measurement
Oscillator PrototypeOscillator Prototype ˃ Optimization of size and box weight, hardness
» Concerns with material CET, electrical and thermal conductivity.
» Gold wire for bonding
» Epoxy glues to attach chip
» Adhesives glues to PCB
» Nickel and gold plating
» Bonding with gold wire
Oscillator PrototypeOscillator Prototype
Oscillator PrototypeOscillator Prototype Thermal test cycles
Between -20ºC and 70ºC a
maximum frequency drift of 12
MHz.
Oscillator PrototypeOscillator Prototype Vacuum tests
To avoid any particles or gases released
not expected
Oscillator PrototypeOscillator Prototype EMC tests
- US Military, agreement concern
0
1 0
2 0
3 0
4 0
5 0
6 0
7 0
8 0
L e v e l [ d Bµ V/ m ]
2 G 2 . 2 G 2 . 4 G 2 . 6 G 2 . 8 G 3 G 3 . 2 G 3 . 6 G
Fr e q u e n c y [ Hz ]
+
+
+x
x
x
M a r k e r : 2 . 2 G Hz 3 8 . 1 d Bµ V/ m
x M ES CTTB_ EBB_ 1 1 _ r e d + M ES CTTB_ EBB_ 1 1 _ r e d 2
M ES CTTB_ EBB_ 1 1 _ p r e M ES CTTB_ EBB_ 1 1 _ p r e 2
Overall Overall experimentexperiment
Final prototypeFinal prototype Oscillators: Supply and control RF power, Id Supply values temperature Radiation level measurements
FM Radio
Radio over 3G
DAB Satellite
Radio over TDT
LTE …
Improved Radios will have impose cleaver ways to power management.
This implies that radios will have “intelligence”
from its own.
Challenges Challenges University of Aveiro Approach
nbcarvalho@ua.pt
1º Prémio PLUG APRITEL 2010
AcknowledgementsAcknowledgements We would like to thank the fruitful discussions with: Prof. José Carlos Pedro, Prof. Nuno Matos and Eng. Cupido Prof. Mendiratta and Eng. Jorge Monteiro for the vacuum tests and finally to Portuguese Communications Authority (ANACOM) for the electromagnetic compatibility tests.
Start Apr - 2012
posrad.web.ua.pt
Post graduation in Radio System DesignPost graduation in Radio System Design
POSRAD is an advanced postgraduate course that offers an
opportunity for electrical engineers to update and advance
their knowledge on the area of wireless communication systems.
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