LINER LTC5544 4ghz to 6ghz high dynamic range downconverting mixer Datasheet

DEMO MANUAL DC1885A
LTC5544
4GHz to 6GHz High Dynamic
Range Downconverting Mixer
DESCRIPTION
Demonstration circuit 1885A is a 4GHz to 6GHz high dynamic range downconverting mixer featuring the LTC®5544.
The LTC5544 is part of a family of high dynamic range, high
gain passive downconverting mixers covering the 600MHz
to 6GHz frequency range. The demo circuit 1885A and
the LTC5544 are optimized for 4GHz to 6GHz RF applications. The LO frequency must fall within the 4.2GHz to
5.8GHz range for optimum performance.
The LTC5544 is designed for 3.3V operation, however the
IF amplifier can be powered with 5V for the highest P1dB.
The LTC5544’s high level of integration minimizes the total
solution cost, board space and system-level variation,
while providing the highest dynamic range for demanding
receiver applications.
High Dynamic Range Downconverting Mixer Family
DEMO
NUMBER
IC PART
NUMBER
RF RANGE
LO RANGE
DC1431A-A
LTC5540
600MHz to 1.3GHz 700MHz to 1.2GHz
DC1431A-B
LTC5541
1.3GHz to 2.3GHz
1.4GHz to 2.0GHz
DC1431A-C
LTC5542
1.6GHz to 2.7GHz
1.7GHz to 2.5GHz
DC1431A-D
LTC5543
2.3GHz to 4GHz
2.4GHz to 3.6GHz
DC1885A
LTC5544
4GHz to 6GHz
4.2GHz to 5.8GHz
Design files for this circuit board are available at
http://www.linear.com/demo
L, LT, LTC, LTM, μModule, Linear Technology and the Linear logo are registered trademarks of
Linear Technology Corporation. All other trademarks are the property of their respective owners.
PERFORMANCE SUMMARY
TC = 25°C, VCC = VCC_IF = 3.3V, SHDN = Low, PLO = 2dBm, PRF = –3dBm (Δf =
2MHz, –3dBm/tone for two-tone tests), unless otherwise noted. (Note 1)
PARAMETER
CONDITIONS
VALUE
VCC Supply Voltage Range
3.1 to 3.5
VCC_IF Supply Voltage Range
3.1 to 5.3
Total Supply Current (VCC + VCC_IF)
UNITS
V
V
194
mA
≤500
μA
SHDN Input Low Voltage (IC On)
<0.3
V
SHDN Input High Voltage (IC Off)
>3
V
Total Supply Current During Shutdown
SHDN = High
LO Input Frequency Range
4.2 to 5.8
GHz
>12
dB
LO Input Return Loss
Z0 = 50Ω, fLO = 4.2GHz to 5.8GHz
LO Input Power Range
fLO = 4.2GHz to 5.8GHz
RF Input Frequency Range
Low Side LO
High Side LO
RF Input Return Loss
Z0 = 50Ω, fRF = 4.2GHz to 6GHz
>12
dB
IF Output Frequency
Can be Rematched to Other Frequencies.
240
MHz
>12
dB
IF Output Return Loss
–1 to 5
dBm
4.2 to 6.0
4.0 to 5.8
GHz
GHz
LO to RF Leakage
fLO = 4.2GHz to 5.8GHz, Requires C2
<-30
dBm
LO to IF Leakage
fLO = 4.2GHz to 5.8GHz
<-21
dBm
RF to LO Isolation
fRF = 4GHz to 6GHz
>38
dB
RF to IF Isolation
fRF = 4GHz to 6GHz
>29
dB
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DEMO MANUAL DC1885A
PERFORMANCE SUMMARY
TC = 25°C, VCC = VCC_IF = 3.3V, SHDN = Low, PLO = 2dBm, PRF = –3dBm (Δf =
2MHz, –3dBm/tone for two-tone tests), unless otherwise noted. (Note 1)
PARAMETER
CONDITIONS
VALUE
UNITS
Low Side LO Downmixer Application: RF = 4.2GHz to 6GHz, IF = 240MHz, fLO = fRF – fIF
Conversion Gain
RF = 4900MHz
RF = 5250MHz
RF = 5800MHz
7.9
7.4
6.4
dB
dB
dB
2-Tone Input 3rd Order Intercept
RF = 4900MHz
RF = 5250MHz
RF = 5800MHz
25.4
25.9
25.8
dBm
dBm
dBm
2-Tone Input 2nd Order Intercept
fRF1 = 5371MHz, fRF2 = 5130MHz, fLO = 5010MHz,
fIM2 = fRF1 – fRF2
43.2
dBm
SSB Noise Figure
RF = 4900MHz
RF = 5250MHz
RF = 5800MHz
10.3
11.3
12.8
dB
dB
dB
SSB Noise Figure Under Blocking
fRF = 5250MHz, fLO = 5010MHz, fBLOCK = 4910MHz,
PBLOCK = 5dBm
16.9
dB
2RF – 2LO Output Spurious Product (fRF = fLO + fIF/2)
fRF = 5130MHz at –10dBm, fLO = 5010MHz
–58.3
dBc
3RF – 3LO Output Spurious Product (fRF = fLO + fIF/3)
fRF = 5090MHz at –10dBm, fLO = 5010MHz
–77
dBc
Input 1dB Compression
RF = 5250MHz, VCC_IF = 3.3V
RF = 5250MHz, VCC_IF = 5V
11.4
14.6
dBm
dBm
High Side LO Downmixer Application: RF = 4GHz to 5.8GHz, IF = 240MHz, fLO = fRF + fIF
Conversion Gain
RF = 4500MHz
RF = 4900MHz
RF = 5250MHz
8.0
7.7
7.3
dB
dB
dB
2-Tone Input 3rd Order Intercept
RF = 4500MHz
RF = 4900MHz
RF = 5250MHz
24.2
25.1
24.0
dBm
dBm
dBm
2-Tone Input 2nd Order Intercept
fRF1 = 4779MHz, fRF2 = 5020MHz, fLO = 5140MHz,
fIM2 = fRF2 – fRF1
39.8
dBm
SSB Noise Figure
RF = 4500MHz
RF = 4900MHz
RF = 5250MHz
10.7
11.0
11.7
dB
dB
dB
2LO – 2RF Output Spurious Product (fRF = fLO – fIF/2)
fRF = 5020MHz at –10dBm, fLO = 5140MHz
–55
dBc
3LO – 3RF Output Spurious Product (fRF = fLO – fIF/3)
fRF = 5060MHz at –10dBm, fLO = 5140MHz
–75
dBc
Input 1dB Compression
RF = 4900MHz, VCC_IF = 3.3V
RF = 4900MHz, VCC_IF = 5V
11.3
14.5
dBm
dBm
Note 1: Subject to change without notice. Refer to the latest LTC5544 data sheet for most-up-to-date specifications.
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DEMO MANUAL DC1885A
DETAILED DESCRIPTION
Absolute Maximum Ratings
LO Inputs
NOTE: Stresses beyond Absolute Maximum Ratings may
cause permanent damage to the device. Exposure to any
Absolute Maximum Rating condition for extended periods
may affect device reliability and lifetime.
The LTC5544’s LO amplifiers are optimized for the 4.2GHz
to 5.8GHz LO frequency range. LO frequencies above and
below this frequency range may be used with degraded
performance.
Supply Voltage (VCC)...............................................4.0V
IF Supply Voltage (VCC_IF)..................................... 5.5V
Shutdown Voltage (SHDN) ............. –0.3V to VCC + 0.3V
LO Input Power (4GHz to 6GHz)............................ 9dBm
RF Input Power (4GHz to 6GHz) ...........................15dBm
Operating Temperature Range (TC) ........–40°C to 105°C
The nominal LO input level is 2dBm. The LO input power
range is between –1dBm and 5dBm.
Supply Voltage Ramping
Fast ramping of the supply voltage can cause a current
glitch in the internal ESD protection circuits. Depending on
the supply inductance, this could result in a supply voltage transient that exceeds the maximum rating. A supply
voltage ramp time of greater than 1ms is recommended.
IF Output
Demonstration Circuit 1885A features a single-ended,
50Ω-matched IF output for 240MHz. The impedance
matching is realized with a bandpass topology using an
IF transformer as shown in Figure 1.
T1
IF+
4:1
C10
L1
L2
VCCIF
Do not clip powered test leads directly onto the demonstration circuit’s VCC and VCC_IF turrets. Instead, make
all necessary connections with power supplies turned off,
and then increase to operating voltage.
C8
15
IF+
LTC5544
14
IF –
Figure 1. IF Output with Bandpass Matching
Shutdown Feature
When the SHDN voltage is logic Low (<0.3V), the chip is
enabled. When the SHDN voltage is logic High (>3V), the
chip is disabled, and the current consumption is reduced
to below 500μA. The SHDN must be pulled Low or High. If
left floating, the On/Off state of the IC will be indeterminate.
A logic table for the SHDN is shown in Table 2.
Demonstration Circuit 1885A can be easily reconfigured
for other IF frequencies by simply replacing inductors L1
and L2. L1 and L2 values for several common IF frequencies are presented in Table 3, and return losses are plotted
in Figure 2.
Table 3. L1, L2 vs IF Frequencies
IF FREQUENCY (MHz)
L1, L2 (nH)
SHDN
IC STATE
140
220
Low
On
190
150
Off
240
150
305
82
380
56
456
39
Table 2. SHDN Logic Table
High
RF Input
The RF input of Demonstration Circuit 1885A is matched
to 50Ω from 4.2GHz to 6GHz with better than 12dB return
loss. For the RF input to be matched, the LO input must
be driven. The RF input impedance is somewhat dependent
on LO frequency and, to a lesser extend, LO input power.
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DEMO MANUAL DC1885A
DETAILED DESCRIPTION
0
5
IF PORT RETURN LOSS (dB)
Demonstration Circuit 1885A’s IF output can be converted
to discrete IF Balun matching with minimal modifications.
Follow the procedures below, and refer to Figure 4.
L1, L2 = 150 nH
L1, L2 = 82nH
L1, L2 = 39nH
DISCRETE BALUN 456MHz
10
a. Remove existing L1, L2, C4, C5, and T1.
15
b. Install L6 at location L2.
20
c. Install L7 at location R2.
25
d. Install C13 between the pads of L1 and C4.
30
100 150 200 250 300 350 400 450 500 550 600
IF FREQUENCY (MHz)
e. Install L5 and C14 on the pads of T1.
f. Install C15 across the pads of T1.
Figure 2. IF+ Port Output Return Loss
For many applications, it is possible to replace the IF
transformer with the discrete IF Balun shown in Figure 3.
See the LTC5544 data sheet for details.
IF+
C15
L5
C13
15
IF+
C14
L6
VCCIF
L7
LTC5544
14
IF –
Figure 3. IF Output with Discrete IF Balun Matching
Figure 4. Modifications for Discrete IF Balun Matching
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DEMO MANUAL DC1885A
MEASUREMENT EQUIPMENT AND SETUP
The LTC5544 is a high dynamic range downconverting
mixer IC with very high input third order intercept. Accuracy
of its performance measurement is highly dependent on
equipment setup and measurement technique. The recommended measurement setups are presented in Figure 5,
Figure 6 and Figure 7. The following precautions should
be observed:
7. Spectrum analyzers can produce significant internal
distortion products if they are overdriven. Generally,
spectrum analyzers are designed to operate at their best
with about 30dBm at their input filter or preselector.
Sufficient spectrum analyzer input attenuation should be
used to avoid saturating the instrument, but too much
attenuation reduces sensitivity and dynamic range.
1. Use high performance signal generators with low harmonic output and low phase noise, such as the Rohde
& Schwarz SME06. Filters at the signal generators’
outputs may also be used to suppress higher order
harmonics.
8. Before taking measurements, the system performance
should be evaluated to ensure that:
2. A high quality RF power combiner that provide broadband 50Ω termination on all ports and have good
port-to-port isolation should be used, such as the
MCLI PS2-17.
3. Use high performance amplifiers with high IP3 and
high reverse isolation on the outputs of the RF signal
generators to improve source isolation to prevent the
sources from modulating each other and generating
intermodulation products.
4. Use attenuator pads with good VSWR on the demonstration circuit’s input and output ports to improve
source and load match to reduce reflections, which may
degrade measurement accuracy.
5. A high dynamic range spectrum analyzer, such as the
Rohde & Schwarz FSEM30 should be used for linearity
measurement.
6. Use narrow resolution bandwidth (RBW) and engage
video averaging on the spectrum analyzer to lower the
displayed average noise level (DANL) in order to improve
sensitivity and to increase dynamic range. However, the
trade off is increased sweep time.
a. Clean input signals can be produced. The 2-tone
signals’ OIP3 should be at least 15dB better than
the DUT’s IIP3.
b. The spectrum analyzer’s internal distortion is
minimized.
c. The spectrum analyzer has enough dynamic range
and sensitivity. The measurement system’s IIP3
should be at least 15dB better than the DUT’s OIP3.
d. The system is accurately calibrated for power and
frequency.
A Special Note About RF Termination
The LTC5544 consists of a high linearity passive doublebalanced mixer core and IF buffer amplifier. Due to the
bidirectional nature of all passive mixers, LO±IF mixing
product is always present at the RF input, typically at a level
of 12dB below the RF input signal. If the LO±IF “PseudoImage Spur” is not properly terminated, it may interfere
with the source signals, and can degrade the measured
linearity and noise figure significantly. To avoid interference
from the LO±IF “Pseudo-Image Spur”, terminate the RF
input port with an isolator, diplexer, or attenuator. In the
recommended measurement setups presented in Figure 6
and Figure 7, the 6dB attenuator pad at the demonstration
circuit’s RF input serves this purpose.
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DEMO MANUAL DC1885A
QUICK START PROCEDURE
Demonstration circuit 1885A is easy to set up to evaluate the performance of the LTC5544. Refer to Figure 5,
Figure 6 and Figure 7 for proper equipment connections
and follow the procedure below:
NOTE: Care should be taken to never exceed absolute
maximum input ratings. Make all connections with RF
and DC power off.
Return Loss Measurements
1. Configure the Network Analyzer for return loss measurement, set appropriate frequency range, and set the test
signal to 2dBm.
2. Calibrate the Network Analyzer.
3. Connect all test equipment as shown in Figure 5 with
the signal generator and the DC power supply turned
off.
4. Increase VCC supply voltage to 3.3V, and verify that
the current consumption is approximately 194mA with
the LO signal applied. The supply voltage should be
confirmed at the demo board VCC and GND terminals
to account for test lead ohmic losses.
5. Set the LO source (Signal Generator 1) to provide a
2dBm, CW signal to the demo board LO input port at
appropriate LO frequency.
6. With the LO signal applied, and the unused demo board
ports terminated in 50Ω, measure return losses of the
RF input and IF+ output ports.
7. Terminate the RF input and the IF+ output ports in 50Ω.
Measure return loss of the LO input port.
RF Performance Measurements
1. Connect all test equipment as shown in Figure 6 with
the signal generators and the DC power supply turned
off.
2. Increase VCC supply voltage to 3.3V, and verify that
the current consumption is approximately 194mA with
the LO signal applied. The supply voltage should be
confirmed at the demo board VCC and GND terminals
to account for test lead ohmic losses.
3. Set the LO source (Signal Generator 1) to provide a
2dBm, CW signal to the demo board LO input port at
appropriate LO frequency.
4. Set the RF sources (Signal Generators 2 and 3) to provide two –3dBm CW signals, 2MHz apart, to the demo
board RF input port at the appropriate RF frequency.
5. Measure the resulting IF output on the Spectrum
Analyzer:
a. The wanted two-tone IF output signals are at:
fIF1 = fRF1 – fLO, and
fIF2 = fRF2 – fLO for low side LO,
and
fIF1 = fLO – fRF1, and
fIF2 = fLO – fRF2 for high side LO
b. The 3rd order intermodulation products which are
closest to the wanted IF signals are used to calculate
the Input 3rd Order Intercept:
fIM3,1 = fRF1 – fLO – ΔIF, and
fIM3,2 = fRF2 – fLO + ΔIF for low side LO,
and
fIM3,1 = fLO – fRF1 + ΔIF, and
fIM3,2 = fLO – fRF2 – ΔIF for high side LO
where ΔIF = fRF2 – fRF1
6. Calculate Input 3rd Order Intercept:
IIP3 = (ΔIM3)/2 + PRF
where ΔIM3 = PIF – PIM3. PIF is the lowest IF output
signal power at either fIF1 or fIF2. PIM3 is the highest 3rd
order intermodulation product power at either fIM3,1 or
fIM3,2. PRF is the per-tone RF input power.
7. Turn off one of the RF signal generators, and measure
Conversion Gain, RF to IF isolation, LO to IF leakage,
and Input 1dB compression point.
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DEMO MANUAL DC1885A
QUICK START PROCEDURE
Noise Figure Measurement
1. Configure and calibrate the noise figure meter for mixer
measurements.
2. Connect all test equipment as shown in Figure 7 with
the signal generator and the DC power supply turned
off.
4. Set the LO source (Signal Generator 1) to provide a
2dBm, CW signal to the demo board LO input port at
appropriate LO frequency.
5. Measure the single-sideband noise figure.
3. Increase VCC supply voltage to 3.3V, and verify that
the current consumption is approximately 194mA with
the LO signal applied. The supply voltage should be
confirmed at the demo board VCC and GND terminals
to account for test lead ohmic losses.
Figure 5. Proper Equipment Setup for Return Loss Measurements
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DEMO MANUAL DC1885A
QUICK START PROCEDURE
Figure 6. Proper Equipment Setup for RF Performance Measurements
Figure 7. Proper Equipment Setup for Noise Figure Measurement
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DEMO MANUAL DC1885A
PCB LAYOUT
Top Layer
Ground Plane
Power Plane
Bottom Layer
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DEMO MANUAL DC1885A
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
1
1
C1
CAP.,THIN-FILM, 0.6pF, ±0.03pF, 25V, 0402
AVX, 04023J0R6QBS
2
1
C3
CAP.,THIN-FILM, 1.2pF, ±0.05pF, 25V, 0402
AVX, 04023J1R2ABS
3
2
C4, C6
CAP., C0G, 22pF, ±1%, 50V, 0402
AVX, 04025A220FAT
4
1
C5
CAP., X7R, 1000pF, ±5%, 50V, 0402
AVX, 04025C102JAT
5
2
C7, C8
CAP., X5R, 1μF, ±10%, 10V, 0603
AVX, 0603ZD105KAT
6
0
C2, R1, R2, R3
OPT, 0402
7
5
E1, E2, E3, E4, E5
TURRET, PAD 0.061"
MILL-MAX, 2308-2-00-80-00-00-07-0
8
4
J1, J2, J3, J4
CONN., SMA 50Ω EDGE-LAUNCH
E.F. JOHNSON, 142-0701-851
9
2
L1, L2
IND., WIRE-WOUND, 150nH, ±2%, 0603
COILCRAFT, 0603CS-R15XGLU
10
3
L3, R4, R5
RES., CHIP, 0Ω, 0603
VISHAY, CRCW06030000Z0EA
11
1
L4
IND., WIRE-WOUND, 2.2nH, ±5%, 0402
COILCRAFT, 0402HP-2N2XJLU
12
1
T1
TRANSFORMER, SMT, RF WIDEBAND, 4:1
MINI-CIRCUITS, TC4-1W-7ALN+
13
1
U1
IC., LINEAR TECHNOLOGY, LTC5544IUF, QFN 4x4
LINEAR TECHNOLOGY, LTC5544IUF#PBF
14
1
FAB, PRINTED CIRCUIT BOARD
DEMO CIRCUIT 1885A
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DEMO MANUAL DC1885A
SCHEMATIC DIAGRAM
dc1885af
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
11
DEMO MANUAL DC1885A
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions:
This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT
OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety
measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union
directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.
If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date
of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU
OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS
FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR
ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims
arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all
appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or
agency certified (FCC, UL, CE, etc.).
No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.
Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and
observe good laboratory practice standards. Common sense is encouraged.
This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
dc1885af
12 Linear Technology Corporation
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