BFP740 SiGe:C Ultra Low Noise RF Transistor in 5

Application Note, Rev. 1.0, November 2008
Application Note No. 169
BFP740 SiGe:C Ultra Low Noise RF Transistor in
5 – 6 GHz LNA Application with 15 dB Gain, 1.3 dB
Noise Figure & ~ 100 nanosecond Turn-On / Turn-Off
Time
(For 802.11a & 802.11n “MIMO” Wireless LAN Applications)
Small Signal Discretes
Never stop thinking
Edition 2008-11-18
Published by
Infineon Technologies AG
81726 München, Germany
© Infineon Technologies AG 2008.
All Rights Reserved.
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IMPLEMENTATION OF THE INFINEON TECHNOLOGIES COMPONENT ONLY AND SHALL
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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
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(INCLUDING WITHOUT LIMITATION WARRANTIES OF NON-INFRINGEMENT OF
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Application Note No. 169
BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
Application Note No. 169
Revision History: 2008-11-18, Rev 1.0
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Additional Information:
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Direct link to RF Transistor Datasheets / Specifications: www.infineon.com/rf.specs
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For Application Notes: www.infineon.com/rf.appnotes
Application Note No. 169
BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
1
BFP740 SiGe:C Ultra Low Noise RF Transistor in 5 – 6 GHz LNA
Application with 15 dB Gain, 1.3 dB Noise Figure & 100 nanosecond
Turn-On / Turn-Off Time
Overview
• Infineon Technologies BFP740 is a high gain, ultra low noise Silicon-Germanium-Carbon
(SiGe:C) HBT device suitable for a wide range of Low Noise Amplifier (LNA) applications.
2
•
The circuit shown in this document is targeted for 802.11a & 802.11n “MIMO” applications in
the Wireless Local Area Network (WLAN) market, particularly for Access Points (AP’s) which
require external LNA’s to fulfill high-sensitivity / low Bit Error Rate (BER) / long range
requirements. LNA’s for this application must be able to switch on / off within about 1
microsecond, or 1000 nanoseconds. Charge storage (capacitance) used in the circuit is
minimized to reduce turn-on / turn-off times. Trade-off for reduced capacitance values is a
reduction in Third Order Intercept (IP3) performance. Amplifier is Unconditionally Stable (µ1
> 1.0) from 10 MHz – 12 GHz.
•
External parts count (not including BFP740 transistor) = 12; 6 capacitors, 3 resistors, and 3
chip inductors. All passives are ‘0402’ case size. BFP740 transistor package is RoHS –
compliant, industry-standard SOT343 / type.
Summary Of Performance Data
(T=25 °C, network analyzer source power ≈ -25 dBm, VCC = 3.0 V, VCE = 2.2 V, IC=13.3 mA, ZS=ZL=50 Ω )
Frequency
* NF ** IIP3 ** OIP3 IP1dB OP1dB
MHz
dB[s11]2 dB[s21]2 dB[s12]2 dB[s22]2 dB dBm
dBm dBm dBm
- 11.3
-21.8
-9.7
--------5150
15.2
1.3
-16.7
-21.0
-16.2
+9.3
+24.4 -6.2
+7.9
5470
15.1
1.3
-10.4
-20.9
-17.3
--------5825
14.3
1.4
- 2.5
- 39.0
- 2.5
--------2500
8.3
--* does not extract PCB loss. If PCB loss (at input) were extracted, noise figure would be ~ 0.2 dB lower.
Note: reverse isolation ( dB[s12]2 ) when DC power to LNA is OFF = -10.3 dB @ 5470 MHz.
3
Details of PC Board Construction
PC board is fabricated from standard, low-cost “FR4” glass-epoxy material. A cross-section diagram of
the PC board is given below.
PCB CROSS SECTION
0.012 inch / 0.305 mm
TOP LAYER
INTERNAL GROUND PLANE
0.028 inch / 0.711 mm ?
LAYER FOR MECHANICAL RIGIDITY OF PCB, THICKNESS HERE NOT CRITICAL AS
LONG AS TOTAL PCB THICKNESS DOES NOT EXCEED 0.045 INCH / 1.14 mm
(SPECIFICATION FOR TOTAL PCB THICKNESS: 0.040 + 0.005 / - 0.005 INCH;
1.016 + 0.127 mm / - 0.127 mm )
BOTTOM LAYER
Application Note
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Rev. 1.0, 2008-11-18
Application Note No. 169
BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
4
SOT343 Package Outline & Footprint. Dimensions in millimeters (mm).
Application Note
5 / 24
Rev. 1.0, 2008-11-18
Application Note
6 / 24
C1
0.3pF
RF
INPUT
C3
1.5pF
C2
1.0pF
L1
6.8nH
R2
33K
L2
R1
22 ohms
R3
39 ohms
C5
1.5pF
C6
0.75pF
cc
J2
RF OUTPUT
= 3.0 V
= 50 ohm microstripline
L3
1.0nH
C4
33pF
I = 13.3 mA
Q1: VCE = 2.2 V
Q1
1.6nH
BFP740
SiGe:C
Transistor
PCB = 740-081009 Rev A
PC Board Material = Standard FR4
J1
6 capacitors
3 inductors
3 resistors
12 external passives used:
V
5
Inductors are Murata LQP15M Series (formerly LQP10A)
0402 case size. Capacitors and resistors are 0402 case size.
J3
DC Connector
Application Note No. 169
BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
Schematic Diagram
Rev. 1.0, 2008-11-18
Application Note No. 169
BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
6
Bill Of Material (BOM)
Reference
Designator
Value
C1
0.3pF
C2
C3
C4
C5
1.0pF
1.5pF
33pF
1.5pF
0.3pF, 50V, COG ‘0402’ case size
capacitor
Murata GRM1555C1HR30BZ01D or
equivalent
‘0402’ chip capacitor
‘0402’ chip capacitor
‘0402’ chip capacitor
‘0402’ chip capacitor
C6
0.75pF
‘0402’ chip capacitor
Various
L1
6.8nH
6.8nH ‘0402’ case size chip inductor
Murata LQP15M Series or equivalent
Murata
L2
1.6nH
1.6nH ‘0402’ case size chip inductor
Murata LQP15M series or equivalent
Murata
L3
1.0nH
1.0nH ‘0402’ case size chip inductor
Murata LQP15M series or equivalent
Murata
R1
R2
R3
22Ω
33kΩ
39Ω
‘0402’ chip resistor
‘0402’ chip resistor
‘0402’ chip resistor
Various
Various
Various
Q1
---
J1, J2
J3
---
Application Note
Description / Part #
Manufacturer
BFP740 SiGe:C Low Noise RF
Transistor, SOT343 package
Murata, AVX,
etc.
Various
Various
Various
Various
Infineon
Technologies
RF Edge Mount SMA Female Connector,
142-0701-841
MTA-100 Series 5 pin connector
640456-5
PC Board, Part # 740-081009 Rev A
7 / 24
Function
Input Match
Input DC block, Input Matching
RF decoupling / blocking cap
RF decoupling / blocking cap
RF decoupling / blocking cap
Output DC block and output
matching.
Also influences
input match.
RF Choke at LNA input (for DC
bias to base).
RF ‘Choke’ at LNA output, for
DC bias to collector.
Also
influences
matching
and
stability.
Output
matching;
also
influences input match.
For RF stability improvement.
DC biasing (base).
DC biasing (provides DC
negative feedback to stabilize
DC operating point over
temperature
variation,
transistor hFE variation, etc.)
LNA active device.
Emerson /
Johnson
Tyco (AMP)
Input, Output RF connector
Infineon
Technologies
Printed Circuit Board
5 Pin DC connector header
Rev. 1.0, 2008-11-18
Application Note No. 169
BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
7
Scanned Images of PC Board
View of Entire PC Board
Application Note
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Application Note No. 169
BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
Close-In View of LNA Section
Application Note
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Application Note No. 169
BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
8
Noise Figure Measurement Data
Noise Figure Plot, from Rohde and Schwarz FSEK3 + FSEM30
Rohde & Schwarz FSEK3
18 Nov 2008
Noise Figure Measurement
EUT Name:
Manufacturer:
Operating Conditions:
Operator Name:
Test Specification:
Comment:
BFP740 5 - 6 GHz LNA, Fast Switching / Fast Turn ON-OFF Time
Infineon Technologies
T=25 C, V = 3.0V, Vce = 2.2V, I = 13.2mA
Gerard Wevers
WLAN 802.11n, 802.11n
PCB = 740-081009 Rev A; Preamp = MITEQ AFS3-04000800-10-ULN
18 November 2008
Analyzer
RF Att:
Ref Lvl:
0.00 dB
-45.00 dBm
RBW :
VBW :
1 MHz
100 Hz
Range: 30.00 dB
Ref Lvl auto: ON
Measurement
2nd stage corr: ON
Mode: Direct
ENR: 346A_1.ENR
Noise Figure /dB
1.90
1.80
1.70
1.60
1.50
1.40
1.30
1.20
1.10
1.00
0.90
4800 MHz
Application Note
120 MHz / DIV
10/ 24
6000 MHz
Rev. 1.0, 2008-11-18
Application Note No. 169
BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
Noise Figure, Tabular Data
Taken With Rohde & Schwarz FSEM30 + FSEK3
System Preamplifier = MITEQ 4 – 8 GHz LNA
Application Note
Frequency
Nf
4800 MHz
4850 MHz
4900 MHz
4950 MHz
5000 MHz
5050 MHz
5100 MHz
5150 MHz
5200 MHz
5250 MHz
5300 MHz
5350 MHz
5400 MHz
5450 MHz
5500 MHz
5550 MHz
5600 MHz
5650 MHz
5700 MHz
5750 MHz
5800 MHz
5850 MHz
5900 MHz
5950 MHz
6000 MHz
1.26 dB
1.28 dB
1.31 dB
1.28 dB
1.24 dB
1.25 dB
1.24 dB
1.26 dB
1.27 dB
1.26 dB
1.24 dB
1.25 dB
1.27 dB
1.28 dB
1.25 dB
1.27 dB
1.28 dB
1.29 dB
1.34 dB
1.37 dB
1.36 dB
1.37 dB
1.39 dB
1.38 dB
1.40 dB
11/ 24
Temp
97.8 K
99.2 K
102.3 K
99.3 K
95.8 K
97 K
95.7 K
97.9 K
98.8 K
97.9 K
96.1 K
97 K
98.5 K
99.3 K
96.5 K
98.3 K
99.7 K
100.5 K
104.8 K
107.4 K
106.4 K
107.8 K
109.3 K
108.1 K
110.4 K
Rev. 1.0, 2008-11-18
Application Note No. 169
BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
9
Amplifier Compression Point Measurement
Gain Compression at 5470 MHz, VCC = +3.0 V, I = 13.3mA, VCE = 2.2V, T = 25°C:
Rohde & Schwarz ZVB20 Vector Network Analyzer is set up to sweep input power to LNA at a
fixed frequency of 5470 MHz. X-axis of VNA screen-shot below shows input power to LNA being
swept from –30 to –5 dBm. ZVB20 output power is checked / verified against HP E4419A power
meter; ZVB20 output power is ≅ 0.6 dB lower than indicated on ZVB20 due to test cable loss.
Therefore, a 0.6 dB offset is needed.
Input 1 dB compression point = - 5.6 dBm – 0.6 dB offset = - 6.2 dBm
Output 1dB compression point = - 6.2 dBm + (Gain – 1dB) = -6.2 dBm + 14.1 dB = +7.9 dBm
Trc1 S21 dB Mag 1 dB / Ref 15 dB
Cal Offs
1
M 1 -21.72 dBm
• M 2 -5.60 dBm
S21
16
15.096 dB
14.072 dB
M1
15
M2
14
13
12
11
10
9
8
Ch1
Start -30 dBm
Freq 5.47 GHz
Stop -5 dBm
11/19/2008,9:58 PM
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BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
10
Amplifier Stability, Gain, Return Loss and Reverse Isolation Plots
Amplifier Stability - Plot of Stability Factor “
µ”:
1
Rohde and Schwarz ZVB Network Analyzer Calculates and plots stability factor “µ1” of the BFP740F
amplifier in real time. Stability Factor µ1 is defined as follows [1]:
µ
1 - |S11|2
1
=
| S22 – S11* det(S) | + |S21S12|
The necessary and sufficient condition for Unconditional Stability is µ1 > 1.0. In the plot, µ1 > 1.0
over 10 MHz – 12 GHz; amplifier is Unconditionally Stable over 10 MHz – 12 GHz frequency range.
Trc1 µ1 Lin Mag 200 mU/ Ref 1 U
Cal Offs
1
M1
M2
M3
•M 4
µ1
2600
5.150000
5.470000
5.825000
2.500000
GHz
GHz
GHz
GHz
1.3631
1.5290
1.7904
1.1745
U
U
U
U
2400
2200
2000
M3
1800
M2
1600
M1
1400
M4
1200
1000
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
11/19/2008,3:46 AM
[1]. “Fundamentals of Vector Network Analysis”, Michael Hiebel, 4th edition 2008, pages 175 – 177, ISBN
978-3-939837-06-0
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Application Note No. 169
BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
Input Return Loss, Log Mag
10 MHz – 12 GHz Sweep
Trc1 S11 dB Mag 5 dB / Ref 0 dB
Cal Offs
1
M1
M2
M3
•M 4
S11
15
5.150000
5.470000
5.825000
2.500000
GHz
GHz
GHz
GHz
-11.260
-16.659
-10.356
-2.5216
dB
dB
dB
dB
10
5
M4
0
-5
M1
-10
M3
M2
-15
-20
-25
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
11/19/2008,3:41 AM
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Application Note No. 169
BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
Input Return Loss, Smith Chart
Reference Plane = Input SMA Connector on PC Board
10 MHz – 12 GHz Sweep
Trc1 S11 Smith
Ref 1 U
Cal Offs
1
1
S11
0.5
M1
0
0.2
0.5
44.806
j26.428
816.73
2
M 2 5.470000 GHz 67.177
j1.6244
47.263
M 3 5.825000 GHz 43.737
-j29.153
5
937.21
• M 4 2.500000 GHz 8.8992
-j24.106
2.641
M 1 5.150000 GHz
1
M2
2
5
Ω
Ω
pH
Ω
Ω
pH
Ω
Ω
fF
Ω
Ω
pF
M3
-5
M4
-0.5
-2
-1
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
11/19/2008,3:41 AM
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Application Note No. 169
BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
Forward Gain. Input / Output Matching Circuits of LNA reduce gain in 2.4 – 2.5 GHz band.
10 MHz – 12 GHz Sweep
Trc1 S21 dB Mag 5 dB / Ref 0 dB
S21
Cal Offs
M 1M 2
M3
15
1
M1
M2
M3
•M 4
5.150000
5.470000
5.825000
2.500000
GHz
GHz
GHz
GHz
15.183
15.080
14.334
8.3455
dB
dB
dB
dB
M4
10
5
0
-5
-10
-15
-20
-25
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
11/19/2008,3:42 AM
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BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
Reverse Isolation
10 MHz – 12 GHz Sweep
Trc1 S12 dB Mag 5 dB / Ref 0 dB
0
Cal Offs
1
M1
M2
M3
•M 4
S12
-5
5.150000
5.470000
5.825000
2.500000
GHz
GHz
GHz
GHz
-21.817
-21.045
-20.867
-39.035
dB
dB
dB
dB
-10
-15
M3
M 1M 2
-20
-25
-30
-35
M4
-40
-45
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
11/19/2008,3:43 AM
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BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
Reverse Isolation, AMPLIFIER DC POWER TURNED OFF.
10 MHz – 12 GHz Sweep
Trc1 S12 dB Mag 5 dB / Ref 0 dB
0
Cal Offs
S12
-5
M3
M2
M1
-10
1
M1
M2
M3
•M 4
5.150000
5.470000
5.825000
2.500000
GHz
GHz
GHz
GHz
-12.307
-10.338
-8.7906
-29.584
dB
dB
dB
dB
-15
-20
-25
M4
-30
-35
-40
-45
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
11/19/2008,3:43 AM
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BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
Output Return Loss, Log Mag
10 MHz to 12 GHz Sweep
Trc1 S22 dB Mag 3 dB / Ref 0 dB
Cal Offs
1
M1
M2
M3
•M 4
S22
3
5.150000
5.470000
5.825000
2.500000
GHz
GHz
GHz
GHz
-9.7105
-16.215
-17.334
-2.5643
dB
dB
dB
dB
0
M4
-3
-6
M1
-9
-12
M2
M3
-15
-18
-21
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
11/19/2008,3:44 AM
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BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
Output Return Loss, Smith Chart
Reference Plane = Output SMA Connector on PC Board
10 MHz to 12 GHz Sweep
Trc1 S22 Smith
Ref 1 U
Cal Offs
1
1
S22
0.5
M4
M1
M3
0
0.2
0.5
65.366
j36.453
1.127
2
M 2 5.470000 GHz 63.942
j10.997
319.98
M 3 5.825000 GHz 46.773
j12.877
5
351.85
• M 4 2.500000 GHz 7.7159
j11.222
714.40
M 1 5.150000 GHz
M2
1
2
5
Ω
Ω
nH
Ω
Ω
pH
Ω
Ω
pH
Ω
Ω
pH
-5
-0.5
-2
-1
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
11/19/2008,3:45 AM
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BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
11
Amplifier Third Order Intercept (TOI) Measurement
In-Band Third Order Intercept (IIP3) Test.
Input Stimulus: f1=5470 MHz, f2=5471 MHz, -20 dBm each tone.
Input IP3 = -20 + (58.5 / 2) = +9.3 dBm.
Application Note
Output IP3 = +9.3 dBm + 15.1 dB gain = +24.4 dBm.
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BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
12
Amplifier Turn-On / Turn-Off Time Measurements
The amplifier is tested for turn-on / turn-off time. See diagram below. The RF signal generator runs
continuously at a power level sufficient to drive the output of the LNA to approximately 0 dBm when the
LNA has DC power ON.
Agilent
DSO6104A
Digital
Oscilloscope
+3 Volts
Ch. 1 (Trigger, edge)
1 Megaohm input Z
Amplifier
6 dB
Attenuator
Pad
Signal
Generator
f=5470 MHz
Agilent
8473B
Detector
Ch. 2 (50 ohm input Z)
! Note !
Set Ch. 2 Input Impedance to 50 ohms, not 1M ohm! 1M ohm
setting will not allow detector to discharge rapidly, and will give
erroneous results to turn-off time measurment, e.g. will indicate
excessively long turn-off times.
1. Signal Generator set such that output power of BFP740F LNA is approx. 0
dBm when LNA is powered ON
2. Channel 1 of oscilloscope monitors input power supply voltage to
Amplifier (+3.0 volts when ON, ~ 0 volts when OFF)
3. Channel 2 of oscilloscope monitors rectified RF output of Amplifier
4. To make measurement of turn-on time, turn power supply OFF, reset
o’scope, setup trigger to trigger on rising edge of Ch.1
5. To make measurement of turn-off time, turn power supply ON, reset
o’scope, setup trigger to trigger on falling edge of Ch. 1
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Application Note No. 169
BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
a) Turn On Time:
Refer to oscilloscope screen-shot below. Upper trace (yellow, Channel 1) is the DC power supply turnon step waveform whereas the lower trace (green, Channel 2) is the rectified RF output signal of the
LNA stage. Amplifier turn-on time is aproximately 50 nanoseconds, or 0.05microseconds. Main
source of time delay in the LNA turn-on and turn-off events are the R-C time constants formed by (R3 *
C4), [(R2+R3) * C3], etc. Charge storage has been minimized in this circuit so as to speed up turn on
and turn off times. (Refer to Schematic diagram on page 6).
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BFP740 5 – 6 GHz LNA with 100 nSec Turn-On / Turn-Off Time
b) Turn-Off Time:
Rectified RF output signal (lower green trace) takes approximately ~ 125 nanoseconds, or ~0.1
microseconds to settle out after power supply is turned off. Note that input impedance of digital
oscilloscope which senses RF Detector Diode output is set to 50 ohms, rather than 1 Megaohm, to
permit RF Detector Diode to rapidly discharge after Amplifier is turned off.
If input impedance of oscilloscope is set to 1 Megaohm, the RF Detector will have to discharge thorugh
this 1 Megaohm impedance, giving excessively long results for turn-off times.
Application Note
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