Application Notes

H
High IP3 MMIC LNA at 1.8-2.4 GHz
Application note for the BGA2012
The BGA2012 is a MMIC 50 Ω LNA block for cellular applications at 1.8 GHz to 2.4 GHz that
require low noise, high gain and good linearity.
Possible applications:
• 1.8 GHz - DECT - gain 15 dB, low noise 1.7 dB, supply curent 4 mA
• 1.9 GHz - CDMA - high IIP3 +10 dBm, gain 12 dB, NF 2.2 dB, supply current 7 mA
• 2.4 GHz - Blue Tooth - gain 11.5 dB, NF 2.3 dB, supply current 6 mA
The MMIC is produced in the single metal DPO Philips process and is packaged in the small 6
pins SOT363. The circuit is equipped with a control pin that can set the amplifier to low currentlow noise mode or to high current-high linearity mode and/or disable (off) mode.
A simple solution requires only input/output decoupling capacitors.
This report describes an application in which the LNA can be tuned for gain and input IP3. At
1900 Mhz, the input IP3 is adjustable between 5 dBm at 16 dB gain and 10 dBm at 12 dB gain.
Circuit description
The LNA is a one stage amplifier. The RF transistor is biased with the controlled bias circuit
that can set the collector current of RF transistor to the desired value. With the control voltage
from 0 to 3 Volt it is posssible to set the collector current from 0 to 7 mA (enable/disable
H
function as well). The best performance on gain, noise and linearity is achieved in the range of 4
to 7 mA.
Low noise and high gain is obtained by the current source that biases the RF transistor and by the
layout of RF transistor.
The device works directly without the external components except input/output decoupling
capacitors. However, to get even higher gain and linearity (IIP3), a few more external
components are necessary.
The next four examples show some possible applications:
•
•
•
•
version 1 : simple solution with only 2 decoupling capacitors; acceptable gain and low noise
version 2: high gain through output shunt coil ⇒ one component more than version 1
version 3: high IIP3 and high gain with input filter ⇒ three components more than version1
version 4: super high IIP3 ⇒ like version 3 with ustripline to ground
Measured results
General conditions:
Vsupply= 3V, temp=25 deg
Quick overview of all four versions:
frequency=1.9 GHz
Parameter
2
Unit
Gain |S21|
dB
NF
dB
IIP3
dBm
Version1
Version 2
Version 3
Version 4
simple
high gain
high IIP3, gain
high IIP3
13.7
14.0
1.7
1.7
-9
-7
14.9
15.5
1.8
1.8
-9
-7
15.4
15.8
2.0
2.1
0
5
12.0
12.3
2.1
2.3
7
10
Conditions
Isupply [mA]
4
7
4
7
4
7
note:
IIP3 - input IP3 measured with ∆f=100 kHz and Pin -25 dBm
Isupply - is a total supply current from 3 Volt supply source
Control current from a control voltage does not exceed 120 uA. (@max Vc=3V)
The next tabels and figures show more data for each version.
2
H
Version 1
Parameter
Unit
0Gain |S21| 2 dB
NF
1.8 GHz
13.6
14.3
14.4
1.7
1.7
1.7
dB
Return Loss dB
input
10
Return Loss dB
output
9
IIP3
dBm
∆f=100kHz
Frequency
1.9 GHz
2.1 GHz
13.2
12.5
13.9
13.1
14
13.2
1.7
1.8
1.7
1.8
1.7
1.8
9
11
11
11
8
9
9
9
-9
-7
-7
2.4 GHz
11.5
12.1
12.2
2.3
2.3
2.3
12
10
Conditions
Isupply [mA]
Vcontrol [V]
2.0
3.5
5.3
2.6
7
3.0
2.0
3.5
5.3
2.6
7
3.0
3.5
2.0
2.6
5.3
7
3.0
2.0
3.5
2.6
5.3
7
3.0
3.5
2.0
5.3
2.6
7
3.0
Application diagram
Vc
Vs
Vc
Vs
Bias
Circuit
RFoutput
Out
RFinput
In
C2
C1
SOT363
BGA2012
gnd
notes:
1. There are 4 types of demo
board layouts available: no
stripline (marked L0), 0.5 mm,
1.0 mm and 1.5 mm stripline.
The L0 PCB should be used
for application version 1.
2. The metal under pin 5 and 6 is
filled with vias to the ground
plane to reduce inductance.
3. The standard demo board also
needs three 0 Ù SMD’s (0603)
at the spots marked with an X.
Additional components to
adjust the biasing can be
placed at these spots.
C1
C2
x
x
x
C4
C3
<-------20mm------->
Demo board
Component
C1
C2
C3
C4
Component
C1, C2
C3, C4
Value
100 pF
100 pF
22 nF
22 nF
Typ
Philips 0603
Philips 0603
Philips 0603
Philips 0603
Function
DC decoupling capacitors
LF filter of dc supply source
<-------20mm------->
3
H
Version 2
Parameter
Gain |S21| 2
Unit
dB
NF
dB
1.8 GHz
14.8
15.6
16.0
1.7
1.7
1.8
Return Loss dB
input
10
Return Loss dB
output
9
IIP3
dBm
∆f=100kHz
Frequency
1.9 GHz
2.1 GHz
14.5
13.0
15.2
13.8
15.5
14.0
1.7
1.8
1.7
1.9
1.8
1.9
8
10
10
11
9
9
10
10
-9
-7
-7
Conditions
Isupply [mA]
Vcontrol [V]
1.8
3.5
5.3
2.5
7.5
3.0
1.8
3.5
5.3
2.5
7.5
3.0
3.5
1.8
2.5
5.3
7.5
3.0
1.8
3.5
2.5
5.3
7.5
3.0
3.5
1.8
5.3
2.5
7.5
3.0
2.4 GHz
11.0
11.4
11.5
2.2
2.3
2.3
12
10
Application diagram
Vc
C3
Vc
Vs
L1
Vs
Bias
Circuit
Out
RFinput
RFoutput
In
C2
C1
SOT363
BGA2012
gnd
notes:
1. There are 4 types of demo
board layouts available: no
stripline (marked L0), 0.5 mm,
1.0 mm and 1.5 mm stripline.
The L0 PCB should be used for
application version 2.
2. The metal under pin 5 and 6 is
filled with vias to the ground
plane to reduce inductance.
3. The standard demo board also
needs three 0 Ù SMD’s (0603)
at the spots marked with an X.
Additional components to
adjust the biasing can be placed
at these spots.
C1
C2
x
L1
x
x
C4
C3
<-------20mm------->
Demo board
Component
C1
C2
C3
C4
L1
Component
C1, C2
C3, C4
L1
Value
100 pF
100 pF
22 nF
22 nF
10 nH
Typ
Philips 0603
Philips 0603
Philips 0603
Philips 0603
TDK 0603
Function
DC decoupling capacitors
LF filter of dc supply source
Output schunt coil, higher Vce
<-------20mm------->
4
H
Version 3
Parameter
Gain |S21| 2
Unit
dB
NF
dB
1.8 GHz
15.3
16.1
16.2
2.0
2.0
2.1
Return Loss dB
input
23
Return Loss dB
output
10
IIP3
dBm
∆f=100kHz
Frequency
1.9 GHz
2.1 GHz
15.0
13.5
15.7
14.0
15.8
14.1
2.0
2.1
2.1
2.3
2.2
2.3
18
22
23
18
9
10
10
12
-1
3
5
Conditions
Isupply [mA]
Vcontrol [V]
1.8
3.5
5.3
2.5
7.5
3.0
1.8
3.5
5.3
2.5
7.5
3.0
3.5
1.8
2.5
5.3
7.5
3.0
1.8
3.5
2.5
5.3
7.5
3.0
3.5
1.8
5.3
2.5
7.5
3.0
2.4 GHz
10.9
11.4
11.4
2.4
2.5
2.6
14
13
Application diagram
Vc
C5
C3
Vc
C4
Vs
L1
Vs
Bias
Circuit
L2
Out
RFinput
RFoutput
In
C2
C1
SOT363
BGA2012
gnd
notes:
1. There are 4 types of demo
board layouts available: no
stripline (marked L0), 0.5 mm,
1.0 mm and 1.5 mm stripline.
The L0 PCB should be used for
application version 3.
2. The metal under pin 5 and 6 is
filled with vias to the ground
plane to reduce inductance.
3. The standard demo board also
needs three 0 Ù SMD’s (0603)
at the spots marked with an X.
Additional components to
adjust the biasing can be placed
at these spots.
C4
L2
C1
C2
x
L1
x
x
C5
C3
<-------20mm------->
<-------20mm------->
Demo board
Component
C1
C2
C3
C4
C5
L1
L2
Component
C1, C2
C3, C5
L1
L2, C4
Value
100 pF
100 pF
22 nF
100 nF
22 nH
3.9 nH
3.9 nH
Typ
Philips 0603
Philips 0603
Philips 0603
Philips 0805
Philips 0603
TDK 0603
TDK0603
Function
DC decoupling capacitors
LF filter of dc supply source
Output schunt coil, higher Vce
Input LP filter to increase IP3
5
H
Version 4 with 0.5 mm stripline
Parameter
Gain |S21| 2
Unit
dB
NF
dB
1.8 GHz
14.0
14.4
14.5
2.0
2.2
2.2
Return Loss dB
input
11
Return Loss dB
output
8
IIP3
dBm
∆f=100kHz
Frequency
Conditions
1.9 GHz
2.1 GHz 2.4 GHz
Isupply [mA]
Vcontrol [V]
1.8
13.3
12.5
9.9
3.5
5.3
2.5
13.9
12.9
10.3
7.5
3.0
14.0
13.0
10.3
1.8
2.1
2.2
2.5
3.5
5.3
2.5
2.2
2.3
2.7
7.5
3.0
2.3
2.4
2.7
13
3.5
1.8
14
2.5
5.3
14
16
16
7.5
3.0
1.8
8
3.5
2.5
8
5.3
7.5
3.0
8
8
10
1
3.5
1.8
6
5.3
2.5
7*
7.5
3.0
* with 1.5 mm stripline, the IIP3 improves to 10 dBm at 12.2 dB gain
Application diagram
Vc
C5
C3
C4
L1
Vs
Vc
Vs
Bias
Circuit
L2
Out
RFinput
RFoutput
In
C2
C1
SOT363
BGA2012
gnd
u-strip
0.5~1.5 mm, see note
notes:
1. There are 4 types of demo board
layouts available: no stripline, 0.5
mm, 1.0 mm and 1.5 mm stripline;
marked L0, L05, L10, L15.
2. The u-stripline to ground is optimized
for each length. For no stripline, the
metal under pin 5 and 6 is filled with
vias to the ground plane to reduce
inductance. For the stripline versions,
the stripline ends in 2 vias.
3. The standard demo board also needs
three 0 Ù SMD’s (0603) at the spots
marked with an X. Additional
components to adjust the biasing can
be placed at these spots.
C4
L2
C1
u-stripline
C2
x
L1
x
x
C5
C3
<-------20mm------->
Demo board
Component
C1
C2
C3
C4
C5
L1
L2
Value
100 pF
100 pF
22 nF
100 nF
22 nH
3.9 nH
3.9 nH
Component
Function
like in version 3
Typ
Philips 0603
Philips 0603
Philips 0603
Philips 0805
Philips 0603
TDK 0603
TDK0603
<-------20mm------->
6
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