Transcript Présentation PowerPoint

SIC
Design techniques and conception of low phase
noise K-band VCOs in BiCMOS technology
Jérémy Hyvert, David Cordeau, Jean-Marie Paillot, Pascal
Philippe*
Contact email : [email protected]
*NXP Semiconductors
Keywords: VCO, phase noise, K-band, BiCMOS, VSAT, Point-to-point
Context and objectives
Ideal oscillator
Power density
Power density
Phase noise
f
f0
Frequency
domain
 Why do we need low phase noise VCOs?
- To get a carrier frequency highly stable
- To limit perturbations on near channels
 Benefits: possibility to increase the speed
transmission (better BER, wide open Eyediagram)
 Target: -79 dBc/Hz @ 10 kHz from 15GHz
Real oscillator
f
f0
V(t)
Time
domain
V(t)
Jitter
t
t
Methodology
Tank
inductor +
B2B varactors
 Increase tank’s Q factor (custom inductors)
 Reduce flicker noise conversion using back-toback (B2B) varactors
 Create new oscillator architecture
 Use of choke inductors instead of resistors
 Use large resistors
 Couple several oscillators
Active part
bipolar
transistors
Vtune
 Use EDA extraction tools to get the
closest behavior to reality
Results
Post-layout simulations show excellent phase noise performances, low
flicker noise conversion and 9,5% tuning range
-74
15.8
-79
15.6
-84
15.4
15.2
Freq sim
15.0
Flow
14.8
Fhigh
14.6
-109
14.0
-124
4
4.5
PN 100k spec
-104
-119
3.5
PN 100k sim
-99
14.2
2.5
3
Vtune (V)
PN 10k spec
-94
-114
2
PN 10k sim
-89
14.4
1.5
-50
PN 1M sim
PN 1M spec
1
1.5
2
2.5
3
Vtune (V)
3.5
4
4.5
-60
-70
Pahse noise (dBc/Hz)
16.0
1
Free running phase noise @ Vtune = 2,75V
Phase noise (dBc/Hz) vs Vtune (V)
Phase Noise (dBc/Hz)
Frequency (GHz)
Frequency (GHz) vs. Vtune (V)
-80
-90
-100
PN sim
-110
-120
-130
-140
-150
1E+3
1E+4
1E+5
Offset (Hz)
1E+6
1E+7