application note no. 070 - infineon technologies

Appl icat ion Note No. 070High Reverse Isolat ion Ampl i f iers at 900 MHz and 1800 MHz using BGA416

Appl icat ion Note, Rev. 2.0, Jan. 2007

RF & Protect ion Devices

Edition 2007-01-04Published byInfineon Technologies AG81726 München, Germany© Infineon Technologies AG 2009.All Rights Reserved.

LEGAL DISCLAIMERTHE INFORMATION GIVEN IN THIS APPLICATION NOTE IS GIVEN AS A HINT FOR THE IMPLEMENTATION OF THE INFINEON TECHNOLOGIES COMPONENT ONLY AND SHALL NOT BE REGARDED AS ANY DESCRIPTION OR WARRANTY OF A CERTAIN FUNCTIONALITY, CONDITION OR QUALITY OF THE INFINEON TECHNOLOGIES COMPONENT. THE RECIPIENT OF THIS APPLICATION NOTE MUST VERIFY ANY FUNCTION DESCRIBED HEREIN IN THE REAL APPLICATION. INFINEON TECHNOLOGIES HEREBY DISCLAIMS ANY AND ALL WARRANTIES AND LIABILITIES OF ANY KIND (INCLUDING WITHOUT LIMITATION WARRANTIES OF NON-INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OF ANY THIRD PARTY) WITH RESPECT TO ANY AND ALL INFORMATION GIVEN IN THIS APPLICATION NOTE.

InformationFor further information on technology, delivery terms and conditions and prices please contact your nearest Infineon Technologies Office (www.infineon.com).

WarningsDue to technical requirements components may contain dangerous substances. For information on the types in question please contact your nearest Infineon Technologies Office.Infineon Technologies Components may only be used in life-support devices or systems with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system, or to affect the safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body, or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be endangered.

http://www.infineon.com

Application Note No. 070

Application Note 3 Rev. 2.0, 2007-01-04

TrademarksSIEGET® is a registered trademark of Infineon Technologies AG.


Revision History: 2007-01-04, Rev. 2.0Previous Version: 2000-02-03Page Subjects (major changes since last revision)All Document layout change



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

Figure 1 PIN configuration

1.1 IntroductionThe 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 noiseamplifiers, voltage controlled oscillators, buffer amplifiers and others for a wide variety of RF and Wireless endproducts.

Figure 2 Schematic Diagram BGA416

• 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 MHzApplications• 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 1

23

4

AN070_pin_connection.vsd

Top View

RFin, 2 3, GND

GND, 1 4, RFout

AN070_schematic.vsd

RFout, 4

RFin, 2 GND, 3

GND, 1

Bias


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 totalparts-count and reduction in required printed circuit board area. RF impedance matching is done off-chip to allowmaximum flexibility, enabling the BGA416 to be used in a wide variety of applications.

2 The BGA416 in a 900 MHz Amplifier Application900 MHz circuit

Figure 3 900 MHz Application Circuit Diagram

2.1 Performance OverviewThe following table shows the measured performance of the application circuit in Figure 3. All measurementvalues presented in this application note include losses of both PCB and connectors - in other words, the referenceplanes used for measurements are the PCB’s RF SMA connectors. Noise figure and gain results shown do nothave any PCB loss extracted from them.

Table 1 Bill of Material of 900 MHz CircuitName Value Unit Package Manufacturer FunctionC1 100 pF 0402 Various DC blockC2 1.2 pF 0402 Various Output matching, DC blockC3 100 pF 0402 Various RF bypassIC1 BGA416 SOT143 Infineon Technologies Si MMICL1 10 nH 0402 Toko LL1005-FH Input matchingL2 10 nH 0402 Toko LL1005-FH Output matching, RF choke

Table 2 Measured Performance Data at 900 MHz and VCC = 3 VParameter Symbol Value UnitSupply current ICC 5.4 mAInsertion power gain |S21|² 20.6 dBNoise figure NF 1.7 dBInput return loss |S11|² 13.9 dBOutput return loss |S22|² 11.6 dBReverse isolation |S12|² 62 dB

AN070_Application_circuit_900MHz.vsd

L310nH

1

2 3

4

IC1BGA416In

L110nHC1

100pF

C41.2pF Out

C3100pF

Vcc




Figure 4 Insertion Power Gain

Figure 5 Return Loss

Input 1 dB-compression point IP1dB -17.5 dBmInput third order intercept point1) IIP3 -8.8 dBm1) ∆f = 1 MHz; Pin = -35 dBm

Table 2 Measured Performance Data at 900 MHz and VCC = 3 V (cont’d)Parameter Symbol Value Unit

AN070_Gain(f)_900MHz.vsd

17

18

19

20

21

22

0.86 0.88 0.9 0.92 0.94

Frequency [GHz]

Gai

n [d

B]

AN070_Return_Loss(f)_900MHz.vsd

6

8

10

12

14

160.86 0.88 0.9 0.92 0.94

Frequency [GHz]

Ret

urn

Loss

[dB

]

s11

s22




Figure 6 Reverse Isolation

Figure 7 Stability

AN070_Reverse_Isolation(f)_900MHz.vsd

40

45

50

55

60

65

70

75

800.86 0.88 0.9 0.92 0.94

Frequeny [GHz]

Rev

erse

Isol

atio

n [d

B]

AN070_K_B1(f)_900MHz.vsd

0

2

4

6

8

10

12

14

0 1 2 3 4Frequency [GHz]

K, B

1

K

B1




Figure 8 Wide Span Gain

Figure 9 Wide Span Return Loss

AN070_Gain(f)_WS_900MHz.vsd

-20-15-10-505

10152025


Gai

n [d

B]

AN070_Return_Loss(f)_WS_900MHz.vsd

-5

0

5

10

15

20

250 1 2 3 4

Frequency [GHz]

Ret

urn

Loss

[dB

]

s11

s22




Figure 10 Gain Compression

3 The BGA416 in a 1800 MHz Amplifier Application1800 MHz Circuit

Figure 11 1800 MHz Application Circuit Diagram

Table 3 Bill of Material of 1800 MHz CircuitName Value Unit Package Manufacturer FunctionC1 270 pF 0402 Various DC blockC2 1.2 pF 0402 Various Output matching, DC blockC3 10 pF 0402 Various RF bypassIC1 BGA416 SOT143 Infineon Technologies Si MMICL1 4.7 nH 0402 Toko LL1005-FH Input matchingL2 2.2 nH 0402 Toko LL1005-FH Output matching RF choke

AN070_Pout(Pin)_WS_900MHz.vsd

-14-12-10-8-6-4-2024

-35 -30 -25 -20 -15Pin [dBm]

P out

[dB

m]

15161718192021222324

Gai

n [d

B]Gain

Pout

AN070_Application_circuit_1800MHz.vs

L32.2nH

1

2 3

4

IC1BGA416In

L14.7nHC1

270pF

C41.2pF Out

C310pF

Vcc




3.1 Performance OverviewThe following table shows the measured performance of the application circuit in Figure 11. As mentioned beforeall these values were measured at the SMA connectors of the application PCB.

Figure 12 Insertion Power Gain

Table 4 Measured Performance Data at 1800 MHz and VCC = 3 VParameter Symbol Value UnitSupply current ICC 5.4 mAInsertion power gain |S21|² 12.9 dBNoise figure NF 2.1 dBInput return loss |S11|² 19.4 dBOutput return loss |S22|² 23.9 dBReverse isolation |S12|² 38 dBInput 1 dB-compression point IP1dB -13.5 dBmInput third order intercept point1)

1) ∆f = 1 MHz; Pin = -35 dBmIIP3 -3 dBm

AN070_Gain(f)_1800MHz.vsd

10

11

12

13

14

15

1.7 1.75 1.8 1.85 1.9Frequency [GHz]

Gai

n [d

B]




Figure 13 Return Loss

Figure 14 Reverse Isolation

AN070_Return_Loss(f)_1800MHz.vsd

8101214161820222426

1.7 1.75 1.8 1.85 1.9

Frequency [GHz]

Ret

urn

Loss

[dB

]

s11

s22

AN070_Reverse_Isolation(f)_1800MHz.vsd

32

34

36

38

40

421.7 1.75 1.8 1.85 1.9

Frequeny [GHz]

Rev

erse

Isol

atio

n [d

B]




Figure 15 Stability

Figure 16 Wide Span Gain

AN070_K_B1(f)_1800MHz.vsd

0

2

4

6

8

10

12

14


K, B

1

K

B1

AN070_Gain(f)_WS_1800MHz.vsd

-20

-15

-10

-5

0

5

10

15


Gai

n [d

B]


Application Board and Component Placement


Figure 17 Wide Span Return Loss

Figure 18 Gain Compression

4 Application Board and Component PlacementFigure 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 / RFpurposes is the layer with the 0.2 mm FR dielectric thickness. The 0.8 mm RF layer is used solely to providemechanical rigidity and to allow for the use of edge-mount SMA RF connectors.

AN070_Return_Loss(f)_WS_1800MHz.vsd

-5

0

5

10

15

20

25

300 1 2 3 4

Frequency [GHz]

Ret

urn

Loss

[dB

]s11

s22

AN070_Pout(Pin))_WS_1800MHz.vsd

-25

-20

-15

-10

-5

0

-35 -30 -25 -20 -15 -10Pin [dBm]

P out

[dB

m]

10

11

12

13

14

15

Gai

n [d

B]

Gain

Pout



Application Board and Component Placement

Figure 19 Component Placement on the Application PCB

Figure 20 PCB Cross Section

Evaluation boards for the amplifier applications described in this application note are available form InfineonTechnologies.

AN070_Component_Placement.vs

C1 L1

IC1

C2

C3NA

L2

8mm

10mm

RFin RFout

Vcc

AN070_PCB_Cross_Section.vsd

0.8 mm FR4

0.2 mm FR435 µm Cu

35 µm Cu

35 µm Cu

for mechanicalrigidity of PCB

application note no. 070 - infineon technologies

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