A pp l ic a t io n N o t e, R e v . 2. 0 , J a n. 2 00 7
A p p li c a t i o n N o t e N o . 0 7 0
H i g h R e v e r s e I s o l at i o n A m p l i f i e r s at 90 0 M H z a n d
1800 MHz using BGA416
R F & P r o t e c ti o n D e v i c e s
Edition 2007-01-04
Published by
Infineon Technologies AG
81726 München, Germany
© Infineon Technologies AG 2009.
All Rights Reserved.
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Information
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Application Note No. 070
Application Note No. 070
Revision History: 2007-01-04, Rev. 2.0
Previous Version: 2000-02-03
Page
Subjects (major changes since last revision)
All
Document layout change
Trademarks
SIEGET® is a registered trademark of Infineon Technologies AG.
Application Note
3
Rev. 2.0, 2007-01-04
Application Note No. 070
High Reverse Isolation Amplifiers at 900 MHz and 1800 MHz using BGA416
1
High Reverse Isolation Amplifiers at 900 MHz and 1800 MHz using
BGA416
Features
• High Maximum Available Gain of 23 dB at 900 MHz
• Ultra high reverse isolation of 62 dB at 900 MHz
• Integrated on-chip biasing circuit
• Low Noise Figure of 1.3 dB at 900 MHz
Applications
• High Reverse Isolation buffer amplifier for oscillator applications
• Low Noise Amplifier for 800 / 900 MHz, GMS900, 900 MHz
ISM, DCS1800, GPS, 1900 MHz PCS, WLAN, UMTS
• Active element in oscillator circuits
GND, 1
4, RFout
RFin, 2
3, GND
3
2
4
1
Top View
AN070_pin_connection.vsd
Figure 1
PIN configuration
1.1
Introduction
The BGA416 is a monolithic cascode amplifier realized in Infineon Technologies’ SIEGET®25 bipolar process.
The cascode amplifier is a popular transistor configuration used in many RF functional blocks such as low noise
amplifiers, voltage controlled oscillators, buffer amplifiers and others for a wide variety of RF and Wireless end
products.
GND, 1
Bias
RFout, 4
RFin, 2
GND, 3
AN070_schematic.vsd
Figure 2
Schematic Diagram BGA416
Application Note
4
Rev. 2.0, 2007-01-04
Application Note No. 070
The BGA416 in a 900 MHz Amplifier Application
The BGA416 features an integrated, on-chip bias circuit that sets the device’s bias point resulting in a low total
parts-count and reduction in required printed circuit board area. RF impedance matching is done off-chip to allow
maximum flexibility, enabling the BGA416 to be used in a wide variety of applications.
2
The BGA416 in a 900 MHz Amplifier Application
900 MHz circuit
Vcc
C3
100pF
L3
10nH
C4
1.2pF
Out
4
1
IC1
BGA416
In
L1
10nH
C1
100pF
2
3
AN070_Application_circuit_900MHz.vsd
Figure 3
900 MHz Application Circuit Diagram
Table 1
Bill of Material of 900 MHz Circuit
Name
Value
Unit
Package
Manufacturer
Function
C1
100
pF
0402
Various
DC block
C2
1.2
pF
0402
Various
Output matching, DC block
C3
100
pF
0402
Various
RF bypass
IC1
BGA416
SOT143
Infineon Technologies Si MMIC
L1
10
nH
0402
Toko LL1005-FH
Input matching
L2
10
nH
0402
Toko LL1005-FH
Output matching, RF choke
2.1
Performance Overview
The following table shows the measured performance of the application circuit in Figure 3. All measurement
values presented in this application note include losses of both PCB and connectors - in other words, the reference
planes used for measurements are the PCB’s RF SMA connectors. Noise figure and gain results shown do not
have any PCB loss extracted from them.
Table 2
Measured Performance Data at 900 MHz and VCC = 3 V
Parameter
Symbol
Value
Unit
Supply current
ICC
|S21|²
NF
|S11|²
|S22|²
|S12|²
5.4
mA
20.6
dB
1.7
dB
13.9
dB
11.6
dB
62
dB
Insertion power gain
Noise figure
Input return loss
Output return loss
Reverse isolation
Application Note
5
Rev. 2.0, 2007-01-04
Application Note No. 070
The BGA416 in a 900 MHz Amplifier Application
Table 2
Measured Performance Data at 900 MHz and VCC = 3 V (cont’d)
Parameter
Input 1 dB-compression point
Input third order intercept point
1) ∆f = 1 MHz; Pin = -35 dBm
1)
Symbol
Value
Unit
IP1dB
IIP3
-17.5
dBm
-8.8
dBm
22
Gain [dB]
21
20
19
18
17
0.86
0.88
0.9
0.92
0.94
Frequency [GHz]
AN070_Gain(f)_900MHz.vsd
Figure 4
Insertion Power Gain
Return Loss [dB]
6
8
10
12
s11
s22
14
16
0.86
0.88
0.9
0.92
0.94
Frequency [GHz]
AN070_Return_Loss(f)_900MHz.vsd
Figure 5
Return Loss
Application Note
6
Rev. 2.0, 2007-01-04
Application Note No. 070
The BGA416 in a 900 MHz Amplifier Application
Reverse Isolation [dB]
40
45
50
55
60
65
70
75
80
0.86
0.88
0.9
0.92
0.94
Frequeny [GHz]
AN070_Reverse_Isolation(f)_900MHz.vsd
Figure 6
Reverse Isolation
14
12
K, B1
10
K
8
6
4
2
B1
0
0
1
2
3
4
Frequency [GHz]
AN070_K_B1(f)_900MHz.vsd
Figure 7
Stability
Application Note
7
Rev. 2.0, 2007-01-04
Application Note No. 070
The BGA416 in a 900 MHz Amplifier Application
25
20
Gain [dB]
15
10
5
0
-5
-10
-15
-20
0
1
2
3
4
Frequency [GHz]
AN070_Gain(f)_WS_900MHz.vsd
Figure 8
Wide Span Gain
-5
s11
Return Loss [dB]
0
s22
5
10
15
20
25
0
1
2
3
4
Frequency [GHz]
AN070_Return_Loss(f)_WS_900MHz.vsd
Figure 9
Wide Span Return Loss
Application Note
8
Rev. 2.0, 2007-01-04
Application Note No. 070
4
24
2
23
0
22
-2
21
Gain
-4
20
-6
19
-8
18
-10
17
Pout
-12
Gain [dB]
Pout [dBm]
The BGA416 in a 1800 MHz Amplifier Application
16
-14
15
-35
-30
-25
-20
-15
Pin [dBm]
AN070_Pout(Pin)_WS_900MHz.vsd
Figure 10
Gain Compression
3
The BGA416 in a 1800 MHz Amplifier Application
1800 MHz Circuit
Vcc
C3
10pF
L3
2.2nH
C4
1.2pF
Out
4
1
IC1
BGA416
In
C1
270pF
L1
4.7nH
2
3
AN070_Application_circuit_1800MHz.vs
Figure 11
1800 MHz Application Circuit Diagram
Table 3
Bill of Material of 1800 MHz Circuit
Name
Value
Unit
Package
Manufacturer
Function
C1
270
pF
0402
Various
DC block
C2
1.2
pF
0402
Various
Output matching, DC block
C3
10
pF
IC1
BGA416
L1
4.7
L2
2.2
Application Note
0402
Various
RF bypass
SOT143
Infineon Technologies
Si MMIC
nH
0402
Toko LL1005-FH
Input matching
nH
0402
Toko LL1005-FH
Output matching RF choke
9
Rev. 2.0, 2007-01-04
Application Note No. 070
The BGA416 in a 1800 MHz Amplifier Application
3.1
Performance Overview
The following table shows the measured performance of the application circuit in Figure 11. As mentioned before
all these values were measured at the SMA connectors of the application PCB.
Table 4
Measured Performance Data at 1800 MHz and VCC = 3 V
Parameter
Symbol
Value
Unit
Supply current
ICC
|S21|²
NF
|S11|²
|S22|²
|S12|²
IP1dB
IIP3
5.4
mA
12.9
dB
2.1
dB
19.4
dB
23.9
dB
38
dB
-13.5
dBm
-3
dBm
Insertion power gain
Noise figure
Input return loss
Output return loss
Reverse isolation
Input 1 dB-compression point
Input third order intercept point
1)
1) ∆f = 1 MHz; Pin = -35 dBm
15
Gain [dB]
14
13
12
11
10
1.7
1.75
1.8
1.85
1.9
Frequency [GHz]
AN070_Gain(f)_1800MHz.vsd
Figure 12
Insertion Power Gain
Application Note
10
Rev. 2.0, 2007-01-04
Application Note No. 070
The BGA416 in a 1800 MHz Amplifier Application
8
Return Loss [dB]
10
s22
12
14
16
s11
18
20
22
24
26
1.7
1.75
1.8
1.85
1.9
Frequency [GHz]
AN070_Return_Loss(f)_1800MHz.vsd
Figure 13
Return Loss
Reverse Isolation [dB]
32
34
36
38
40
42
1.7
1.75
1.8
1.85
1.9
Frequeny [GHz]
AN070_Reverse_Isolation(f)_1800MHz.vsd
Figure 14
Reverse Isolation
Application Note
11
Rev. 2.0, 2007-01-04
Application Note No. 070
The BGA416 in a 1800 MHz Amplifier Application
14
12
K, B1
10
K
8
6
4
2
B1
0
0
1
2
3
4
Frequency [GHz]
AN070_K_B1(f)_1800MHz.vsd
Figure 15
Stability
15
10
Gain [dB]
5
0
-5
-10
-15
-20
0
1
2
3
4
Frequency [GHz]
AN070_Gain(f)_WS_1800MHz.vsd
Figure 16
Wide Span Gain
Application Note
12
Rev. 2.0, 2007-01-04
Application Note No. 070
Application Board and Component Placement
-5
s11
Return Loss [dB]
0
5
s22
10
15
20
25
30
0
1
2
3
4
Frequency [GHz]
AN070_Return_Loss(f)_WS_1800MHz.vsd
Wide Span Return Loss
0
15
Pout [dBm]
-5
14
Gain
-10
13
-15
12
-20
Gain [dB]
Figure 17
11
Pout
-25
10
-35
-30
-25
-20
-15
-10
Pin [dBm]
AN070_Pout(Pin))_WS_1800MHz.vsd
Figure 18
Gain Compression
4
Application Board and Component Placement
Figure 19 shows the placement of the particular components on the application board. The element labeled “NA”
is not used in the designs described in this application note.
Figure 20 displays the cross section of the application PCB. The layer which is actually used for electrical / RF
purposes is the layer with the 0.2 mm FR dielectric thickness. The 0.8 mm RF layer is used solely to provide
mechanical rigidity and to allow for the use of edge-mount SMA RF connectors.
Application Note
13
Rev. 2.0, 2007-01-04
Application Note No. 070
Application Board and Component Placement
Vcc
C3
8mm
L2
NA
C2
C1
RFout
IC1
RFin
L1
10mm
AN070_Component_Placement.vs
Figure 19
Component Placement on the Application PCB
0.2 mm FR4
35 µm Cu
35 µm Cu
for mechanical
rigidity of PCB
0.8 mm FR4
35 µm Cu
AN070_PCB_Cross_Section.vsd
Figure 20
PCB Cross Section
Evaluation boards for the amplifier applications described in this application note are available form Infineon
Technologies.
Application Note
14
Rev. 2.0, 2007-01-04