Stéphane Bosse Séverin Barth - ASTRON sessions/13De… · Dwingeloo, 13 December 2011 BFCdiff 5...
Transcript of Stéphane Bosse Séverin Barth - ASTRON sessions/13De… · Dwingeloo, 13 December 2011 BFCdiff 5...
1BFCdiffDwingeloo, 13 December 2011
AA-mid / SKA
BeamFormerChip differentialBFCdiff
Stéphane BosseSéverin Barth
2BFCdiffDwingeloo, 13 December 2011
AA-mid / SKA
Cost
General System of Differential BeamFormer
Channel 1
Beam 1
Beam 2
R0
R0 = 200 or 150 ohms
BufferIsolation
R0
R0
R0
Channel 2
Channel 3
Channel 4
R0
R0
3BFCdiffDwingeloo, 13 December 2011
AA-mid / SKAChannel System of Differential BeamFormer
Input Amplifier1 input2 outputs (2 beams)
PhaseShifting8 cellsn*22.5°
Switch0-180°
VGA8 cellsn*0.6 dB
BufferIsolation
4BFCdiffDwingeloo, 13 December 2011
AA-mid / SKALayout of Differential BeamformerChip
X = 1.622 mm with sawlaneY = 1.772 mm with sawlane
Surface = 2.9 mm2
Current = 149.45 mA
Power supply = 3.3 V
Power consumption = 494 mW
Process Qubic4X NXP version 9.0
Differential Beamformer4 channels 2 Beams
PhaseShifting = 360 ° 4 bits (step = 22.5 °)
VGA = 4.5 dB 3 bits
Differential Input impedance matching= 200 or 150 ohms
Differential Output impednce matching= 200 or 150 ohms
Digital control : I2C or SPI
5BFCdiffDwingeloo, 13 December 2011
AA-mid / SKASimulation Layout RC parasitics / Phaseshifting6th state of gain (with inductance Bonding ~ 1,5 nH)
Frequency GHz
dBGain Sdd21 1 input -> 1 output
400 MHz 1500 MHz
16 states of phaseshifting400 MHz 1500 MHz
Frequency GHz
Reflexion Sdd11 1 input
Reflexion Sdd22 1 output
16 states of phaseshiftingdB
Phase Sdd21 1 input -> 1 output
Frequency GHz
16 states of phaseshifting
degree
Frequency GHz
dB Common mode Scc21 1 input -> 1 output
400 MHz
1500 MHz
16 states of phaseshifting
- 12 dB
6BFCdiffDwingeloo, 13 December 2011
AA-mid / SKASimulation Layout RC parasitics / VGA
0 degree of phaseshifting
Frequency GHz
400 MHz 1500 MHz
Gain Sdd21 1 input -> 1 output
8 states of gain
dB
Frequency GHz
400 MHz 1500 MHz
8 states of gain
Reflexion S11 1 input
Reflexion Sdd22 1 output
dB
Phase Sdd21 1 input -> 1 output
Frequency GHz
8 states of gain
degree
7BFCdiffDwingeloo, 13 December 2011
AA-mid / SKASimulation Layout RC parasitics
Noise Figure
Frequency GHz
System Noise Figure
16 states of phaseshifting
dB
Eg
200 ohms
Channel 1
Channel 2 Channel 3
Channel 4
Beam 1
Beam 2
System Noise Figure = NF-6.02
Frequency GHz
System Noise Figure8 states of gain
dB
200 ohms 200 ohms
200 ohms
200 ohms
8BFCdiffDwingeloo, 13 December 2011
AA-mid / SKASimulation Layout RC parasitics / Linearity
Eg
200 ohms
200 ohms 200 ohms
200 ohms
200 ohms
200 ohms
Channel 1
Channel 2 Channel 3
Channel 4
Beam 1
Beam 2
f1
f1
PindBm
PoutdBm
Theory : OIP3 ~ Pout-1dBm + 10.8
EMBRACE : OIP3 ~ Pout-1dBm + 8
400 MHz 1500 MHz
Pout-1dBm -7.53 dBm -9.7 dBm
OIP3 4.2 dBm 0.75 dBm
P-1dBm + 8 0.43 dBm -1.7 dBm
C/IPin = -40 dBm
56 dB 54 dB
The classical simulation of intermodulation order 3rd (OIP3) is unreliable.Add 8 dBm to the output compression point is better.
9BFCdiffDwingeloo, 13 December 2011
AA-mid / SKASimulation Layout RC parasitics / Linearity
Eg
200 ohms
200 ohms
200 ohms
Channel 1
Beam 1
Beam 2
Eg
Channel 2
Eg
Channel 3
Eg
Channel 4
f1
PindBm
f1
PindBm
f1
PindBm
f1
PindBm
f1
PoutdBm
400 MHz 1500 MHz
Pout-1dBm 3.6 dBm 1.6 dBm
OIP3 16.9 dBm 12.5 dBm
P-1dBm + 8 11.6 dBm 9.6 dBm
C/IPin = -40 dBm
56 dB 54 dB
10BFCdiffDwingeloo, 13 December 2011
AA-mid / SKAFuture phase shifting BFC / discussion
Reduce the phaseshifting step : 22.5 ° 11.25° 5.1° ?
Add integrated time delay at 2 beams : 2 integrated time delay / BFC ?
Choose an OIP3 value to reduce consumption ?
Reduce « squint » (squint is proportional to the distancebetween antennas)
Example : OIP3 = 5 dBm -> consumption = 250 mW OIP3 = 8 dBm -> consumprion = 500 mW OIP3 = 11 dBm -> consumption = 1000 mW
Add a True VGA, gain = [-30 dB .. 0 dB] 6 bits for example ?
Add channels or beams ?Example : 8 channels 2 beams
4 channels 4 beams
Add Temperature and Bias voltage control monitoring ?
BFC with Qubic4Xi process, lower consumption (can be)
Bias voltage RF & digital = 3.3 Volts