MAXIM MAX2023 Technical data

General Description
The MAX2023 low-noise, high-linearity, direct upconver­sion/downconversion quadrature modulator/demodulator is designed for single and multicarrier 1500MHz to 2300MHz DCS 1800/PCS 1900 EDGE, cdma2000
®
, WCDMA, and PHS/PAS base-station applications. Direct conversion architectures are advantageous since they significantly reduce transmitter or receiver cost, part count, and power consumption as compared to traditional IF-based double-conversion systems.
In addition to offering excellent linearity and noise perfor­mance, the MAX2023 also yields a high level of compo­nent integration. This device includes two matched passive mixers for modulating or demodulating in-phase and quadrature signals, two LO mixer amplifier drivers, and an LO quadrature splitter. On-chip baluns are also integrated to allow for single-ended RF and LO connec­tions. As an added feature, the baseband inputs have been matched to allow for direct interfacing to the trans­mit DAC, thereby eliminating the need for costly I/Q buffer amplifiers.
The MAX2023 operates from a single +5V supply. It is available in a compact 36-pin thin QFN package (6mm x 6mm) with an exposed paddle. Electrical perfor­mance is guaranteed over the extended -40°C to +85°C temperature range.
Applications
Single-Carrier DCS 1800/PCS 1900 EDGE Base Stations
Single and Multicarrier WCDMA/UMTS Base Stations
Single and Multicarrier cdmaOne™ and cdma2000 Base Stations
Predistortion Transmitters and Receivers
PHS/PAS Base Stations
Fixed Broadband Wireless Access
Military Systems
Microwave Links
Digital and Spread-Spectrum Communication Systems
Video-on-Demand (VOD) and DOCSIS Compliant Edge QAM Modulation
Cable Modem Termination Systems (CMTS)
Features
1500MHz to 2300MHz RF Frequency RangeScalable Power: External Current-Setting
Resistors Provide Option for Operating Device in Reduced-Power/Reduced-Performance Mode
36-Pin, 6mm x 6mm TQFN Provides High Isolation
in a Small Package
Modulator Operation: Meets GSM Spurious Emission of -75dBc at
600kHz Offset at P
OUT
= +6dBm
+23.5dBm Typical OIP3+61dBm Typical OIP2+16dBm Typical OP1dB-54dBm Typical LO Leakage48dBc Typical Sideband Suppression-165dBc/Hz Output Noise DensityBroadband Baseband Input of 450MHz Allows a
Direct Launch DAC Interface, Eliminating the Need for Costly I/Q Buffer Amplifiers
DC-Coupled Input Allows Ability for Offset
Voltage Control
Demodulator Operation:
+38dBm Typical IIP3+59dBm Typical IIP2+30dBm Typical IP1dB9.5dB Typical Conversion Loss9.6dB Typical NF0.025dB Typical I/Q Gain Imbalance0.56° I/Q Typical Phase Imbalance
MAX2023
High-Dynamic-Range, Direct Up-/Downconversion
1500MHz to 2300MHz Quadrature Mod/Demod
_______________________________________________________________________
Maxim Integrated Products
1
Ordering Information
19-0564; Rev 0; 7/06
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
*
EP = Exposed paddle.
+
Denotes lead-free package.
T
= Tape-and-reel package.
cdma2000 is a registered trademark of Telecommunications Industry Association. cdmaOne is a trademark of CDMA Development Group.
EVALUATION KIT
AVAILABLE
PART TEMP RANGE
MAX2023ETX -40°C to +85°C
MAX2023ETX-T -40°C to +85°C
MAX2023ETX+ -40°C to +85°C
MAX2023ETX+T -40°C to +85°C
PIN­PACKAGE
36 Thin QFN-EP* (6mm x 6mm)
36 Thin QFN-EP* (6mm x 6mm)
36 Thin QFN-EP* (6mm x 6mm)
36 Thin QFN-EP* (6mm x 6mm)
PKG
CODE
T3666-2
T3666-2
T3666-2
T3666-2
MAX2023
High-Dynamic-Range, Direct Up-/Downconversion 1500MHz to 2300MHz Quadrature Mod/Demod
2 ________________________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
VCC_ to GND ........................................................-0.3V to +5.5V
BBI+, BBI-, BBQ+, BBQ- to GND..................-4V to (V
CC
+ 0.3V)
LO, RF to GND Maximum Current ......................................30mA
RF Input Power ...............................................................+30dBm
Baseband Differential I/Q Input Power ..........................+20dBm
LO Input Power...............................................................+10dBm
RBIASLO1 Maximum Current .............................................10mA
RBIASLO2 Maximum Current .............................................10mA
RBIASLO3 Maximum Current .............................................10mA
θ
JA
(without air flow) ..........................................…………34°C/W
θ
JA
(2.5m/s air flow) .........................................................28°C/W
θ
JC
(junction to exposed paddle) ...................................8.5°C/W
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering 10s, leaded) .....................+245°C
Lead Temperature (soldering 10s, lead free) ..................+260°C
DC ELECTRICAL CHARACTERISTICS
(MAX2023
Typical Application Circuit
, VCC= +4.75V to +5.25V, GND = 0V, I/Q inputs terminated into 100differential, LO input terminat-
ed into 50, RF output terminated into 50, 0V common-mode input, R1 = 432, R2 = 562, R3 = 300Ω, T
C
= -40°C to +85°C, unless
otherwise noted. Typical values are at V
CC
= +5V, TC= +25°C, unless otherwise noted.) (Note 1)
AC ELECTRICAL CHARACTERISTICS (Modulator)
(MAX2023
Typical Application Circuit
, when operated as a modulator, VCC= +4.75V to +5.25V, GND = 0V, I/Q differential inputs
driven from a 100DC-coupled source, 0V common-mode input, 50LO and RF system impedance, R1 = 432, R2 = 562Ω, R3 = 300, T
C
= -40°C to +85°C. Typical values are at VCC= +5V, V
BBI
= V
BBQ
= 2.66V
P-P
differential, f
IQ
= 1MHz, PLO= 0dBm,
T
C
= +25°C, unless otherwise noted.) (Note 1)
Supply Voltage 4.75 5.00 5.25 V
Supply Current (Note 2) 255 295 345 mA
PARAMETER CONDITIONS MIN TYP MAX UNITS
BASEBAND INPUT
Baseb and Input Di fferential Impedance f
BB Common-Mode Input Voltage Range
Baseband 0.5dB Bandwidth 450 MHz
LO INPUT
LO Input Frequency Range 1500 2300 MHz
LO Input Drive -3 +3 dBm
LO Input Return Loss 15 dB
RF OUTPUT
Output IP2
Output Power (Note 3) +5.6 dBm
PARAMETER CONDITIONS MIN TYP MAX UNITS
1dB
= 1MHz 55
I/Q
= V
V
BBI
P
OUT
= 1.8MHz,
f
BB1
f
= 1.9MHz
BB2
P
OUT
= 1850MHz
f
LO
CW tone
= 1V
BBQ
= 0dBm,
= 0dBm, f
differential ±3.5 V
P-P
= 1.8MHz, f
BB1
fLO = 1750MHz +24.2
fLO = 1850MHz +23.5Output IP3
= 1950MHz +22
f
LO
= 1.9MHz,
BB2
fLO = 1750MHz +15.9
fLO = 1850MHz +14.3Output P
= 1950MHz +12.5
f
LO
+61 dBm
dBm
dBm
MAX2023
High-Dynamic-Range, Direct Up-/Downconversion
1500MHz to 2300MHz Quadrature Mod/Demod
_________________________________________________________________________________________________ 3
AC ELECTRICAL CHARACTERISTICS (Demodulator)
(MAX2023
Typical Application Circuit
when operated as a demodulator, VCC= +4.75V to +5.25V, GND = 0V, 50LO and RF system
impedance, R1 = 432, R2 = 562, R3 = 300, T
C
= -40°C to +85°C. Typical values are at VCC= +5V, PRF= 0dBm, fBB= 1MHz,
P
LO
= 0dBm, fLO= 1850MHz, TC= +25°C, unless otherwise noted.) (Note 1)
AC ELECTRICAL CHARACTERISTICS (Modulator) (continued)
(MAX2023
Typical Application Circuit
, when operated as a modulator, VCC= +4.75V to +5.25V, GND = 0V, I/Q differential inputs
driven from a 100DC-coupled source, 0V common-mode input, 50LO and RF system impedance, R1 = 432, R2 = 562Ω, R3 = 300, T
C
= -40°C to +85°C. Typical values are at VCC= +5V, V
BBI
= V
BBQ
= 2.66V
P-P
differential, f
IQ
= 1MHz, PLO= 0dBm,
T
C
= +25°C, unless otherwise noted.) (Note 1)
Output Power Variation Over Temperature
Output-Power Flatness
RF Return Loss fLO = 1850MHz 17 dB
Single Sideband Rejection
Spurious Emissions
Error Vector Magnitude EDGE input
Output Noise Density ( Note 4) -174 dBm/Hz
Output Noise Floor P
LO Leakage
= +5.6dBm, f
P
OUT
f
= 1850MHz, PRF flatness for fLO swept over
LO
±50MHz range
No external calibration
= +6dBm, f
P
OUT
= 1850MHz, EDGE input
= 0dBm (Note 5) -165 dBm/Hz
OUT
Un-nulled, baseband inputs terminated in 50
I/Q
LO
= 100kHz, TC = -40°C to +85°C 0.25 dB
fLO = 1750MHz 51
fLO = 1850MHz 48
f
= 1950MHz 48
LO
200kHz offset -37.2
400kHz offset -71.4
600kHz offset -84.7
1.2MHz offset -85
RMS 0.67
Peak 1.5
fLO = 1750MHz -59
fLO = 1850MHz -54
f
= 1950MHz -48
LO
0.2 dB
30kHz
dBc
dBc/
%
dBm
RF INPUT
RF Input Frequency 1500 2300 MHz
Conversion Loss fBB = 25MHz 9.5 dB
Noise Figure 9.6 dB
Noise Figure Underblocking Conditions
Input Third-Order Intercept Point
Input Second-Order Intercept Point
Input 1dB Compression Point fBB = 25MHz 29.7 dBm
I/Q Gain Mismatch fBB = 1MHz 0.025 dB
I/Q Phase Mismatch fBB = 1MHz 0.56 Degrees
PARAMETER CONDITIONS MIN TYP MAX UNITS
f
BLOCKER
f
RF
f
RF1
P
RF
f
RF1
P
RF
= 1950MHz, P
= 1850MHz (Note 6)
= 1875MHz, f
= PLO = 0dBm, f
= 1875MHz, f
= PLO = 0dBm, f
BLOCKER
= 1876MHz, fLO = 1850MHz,
RF2
= 24MHz
IM3
= 1876MHz, f
RF2
= 51MHz
IM2
= +11dBm,
= 1850MHz,
LO
20.3 dB
38 dBm
59 dBm
MAX2023
High-Dynamic-Range, Direct Up-/Downconversion 1500MHz to 2300MHz Quadrature Mod/Demod
4 ________________________________________________________________________________________________
Typical Operating Characteristics
(MAX2023
Typical Application Circuit
, VCC= +4.75V to +5.25V, GND = 0V, I/Q differential inputs driven from a 100DC-coupled source
(modulator), V
BBI
= V
BBQ
= 2.6V
P-P
differential (modulator), PRF= +6dBm (demodulator), I/Q differential output drives 50differential load
(demodulator), 0V common-mode input/output, P
LO
= 0dBm, 1500MHz ≤ fLO≤ 2300MHz, 50Ω LO and RF system impedance, R1 = 432Ω,
R2 = 562, R3 = 300Ω, T
C
= -40°C to +85°C. Typical values are at VCC= +5V, fLO= 1850MHz, TC= +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. TEMPERATURE (TC)
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
MAX2023 toc01
-40 -15 10 35 60 85
200
220
240
260
280
300
320
340
360
380
400
VCC = 4.75V
VCC = 5.25V
VCC = 5V
MODULATOR SINGLE-SIDEBAND SUPPRESSION
vs. LO FREQUENCY
LO FREQUENCY (GHz)
SIDEBAND REJECTION (dBc)
MAX2023 toc02
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
20
25
30
35
40
45
50
55
60
65
70
PLO = -3dBm
PLO = 0dBm
PLO = +3dBm
MODULATOR SINGLE-SIDEBAND SUPPRESSION
vs. LO FREQUENCY
LO FREQUENCY (GHz)
SIDEBAND REJECTION (dBc)
MAX2023 toc03
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
20
25
30
35
40
45
50
55
60
65
70
VCC = 4.75V
VCC = 5V
VCC = 5.25V
MODULATOR SINGLE-SIDEBAND SUPPRESSION
vs. LO FREQUENCY
LO FREQUENCY (GHz)
SIDEBAND REJECTION (dBc)
MAX2023 toc04
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
20
25
30
35
40
45
50
55
60
65
70
TC = +85°C
TC = +25°C
TC = -40°C
MODULATOR OUTPUT IP3
vs. LO FREQUENCY
LO FREQUENCY (GHz)
OUTPUT IP3 (dBm)
MAX2023 toc05
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
10
12
14
16
18
20
22
24
26
28
30
TC = +85°C
TC = +25°C
TC = -40°C
f1 = 1.8MHz f
2
= 1.9MHz
MODULATOR OUTPUT IP3
vs. LO FREQUENCY
LO FREQUENCY (GHz)
OUTPUT IP3 (dBm)
MAX2023 toc06
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
10
12
14
16
18
20
22
24
26
28
30
VCC = 4.75V, 5V, 5.25V
f1 = 1.8MHz f
2
= 1.9MHz
Note 1: TCis the temperature on the exposed paddle. Note 2: Guaranteed by production test. Note 3: V
I/Q
= 2.66V
P-P
differential CW input.
Note 4: No baseband drive input. Measured with the baseband inputs terminated in 50. At low output power levels, the output
noise density is equal to the thermal noise floor. See Output Noise Density vs. Output Power plots in
Typical Operating
Characteristics
.
Note 5: The output noise vs. P
OUT
curve has the slope of LO noise (Ln dBc/Hz) due to reciprocal mixing. Measured at 10MHz offset
from carrier.
Note 6: The LO noise (L = 10
(Ln/10)
), determined from the modulator measurements can be used to deduce the noise figure under-
blocking at operating temperature (T
P
in Kelvin), f
BLOCK
= 1 + (LCN- 1) TP/ TO+ LP
BLOCK
/ (1000kTO), where TO= 290K,
P
BLOCK
in mW, k is Boltzmann’s constant = 1.381 x 10
(-23)
J/K, and LCN= 10
(LC/10)
, LCis the conversion loss. Noise figure
underblocking in dB is NF
BLOCK
= 10 x log (f
BLOCK
). Refer to
Application Note 3632
.
MAX2023
High-Dynamic-Range, Direct Up-/Downconversion
1500MHz to 2300MHz Quadrature Mod/Demod
_________________________________________________________________________________________________
5
Typical Operating Characteristics (continued)
(MAX2023
Typical Application Circuit
, VCC= +4.75V to +5.25V, GND = 0V, I/Q differential inputs driven from a 100DC-coupled source
(modulator), V
BBI
= V
BBQ
= 2.6V
P-P
differential (modulator), PRF= +6dBm (demodulator), I/Q differential output drives 50differential load
(demodulator), 0V common-mode input/output, P
LO
= 0dBm, 1500MHz ≤ fLO≤ 2300MHz, 50Ω LO and RF system impedance, R1 = 432Ω,
MODULATOR OUTPUT IP2
vs. LO FREQUENCY
LO FREQUENCY (GHz)
OUTPUT IP2 (dBm)
MAX2023 toc10
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
50
55
60
65
70
75
80
VCC = 5V
VCC = 5.25V
VCC = 4.75V
f1 = 1.8MHz f
2
= 1.9MHz
MODULATOR OUTPUT IP2
vs. LO FREQUENCY
LO FREQUENCY (GHz)
OUTPUT IP2 (dBm)
MAX2023 toc11
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
50
55
60
65
70
75
80
PLO = -3dBm
PLO = 0dBm
PLO = +3dBm
f1 = 1.8MHz f
2
= 1.9MHz
MODULATOR OUTPUT IP2
vs. I/Q COMMON-MODE VOLTAGE
I/Q COMMON-MODE VOLTAGE (V)
OUTPUT IP2 (dBm)
MAX2023 toc12
-3.5 -2.5 -1.5 -0.5 0.5 1.5 2.5 3.5
60
61
62
63
64
65
66
67
68
f1 = 1.8MHz f
2
= 1.9MHz
MODULATOR OUTPUT POWER
vs. INPUT POWER
INPUT POWER (dBm)
OUTPUT POWER (dBm)
MAX2023 toc13
10 12 14 16 18 20 22 24 26 28 30
0
2
4
6
8
10
12
14
16
18
20
VCC = 4.75V, 5V, 5.25V
MODULATOR OUTPUT POWER
vs. INPUT POWER
INPUT POWER (dBm)
OUTPUT POWER (dBm)
MAX2023 toc14
10 12 14 16 18 20 22 24 26 28 30
0
2
4
6
8
10
12
14
16
18
20
PLO = -3dBm
PLO = +3dBm
PLO = 0dBm
MODULATOR OUTPUT POWER
vs. LO FREQUENCY
LO FREQUENCY (GHz)
OUTPUT POWER (dBm)
MAX2023 toc15
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
2
3
4
5
6
7
8
TC = +85°C
TC = +25°C
TC = -40°C
MODULATOR OUTPUT IP3
vs. LO FREQUENCY
30
28
26
24
22
20
18
OUTPUT IP3 (dBm)
16
14
12
10
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
PLO = 0dBm
PLO = -3dBm
LO FREQUENCY (GHz)
f1 = 1.8MHz
= 1.9MHz
f
2
PLO = +3dBm
MAX2023 toc07
MODULATOR OUTPUT IP3
vs. I/Q COMMON-MODE VOLTAGE
26.0
25.5
25.0
24.5
24.0
23.5
OUTPUT IP3 (dBm)
23.0
22.5
22.0
-3.5 -2.5 -1.5 -0.5 0.5 1.5 2.5 3.5 I/Q COMMON-MODE VOLTAGE (V)
f1 = 1.8MHz f
= 1.9MHz
2
MAX2023 toc08
OUTPUT IP2 (dBm)
80
75
70
65
60
55
50
MODULATOR OUTPUT IP2
vs. LO FREQUENCY
TC = +85°C
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 LO FREQUENCY (GHz)
TC = +25°C
TC = -40°C
f1 = 1.8MHz
= 1.9MHz
f
2
MAX2023 toc09
MAX2023
High-Dynamic-Range, Direct Up-/Downconversion 1500MHz to 2300MHz Quadrature Mod/Demod
6 ________________________________________________________________________________________________
Typical Operating Characteristics (continued)
(MAX2023
Typical Application Circuit
, VCC= +4.75V to +5.25V, GND = 0V, I/Q differential inputs driven from a 100DC-coupled source
(modulator), V
BBI
= V
BBQ
= 2.6V
P-P
differential (modulator), PRF= +6dBm (demodulator), I/Q differential output drives 50differential load
(demodulator), 0V common-mode input/output, P
LO
= 0dBm, 1500MHz ≤ fLO≤ 2300MHz, 50Ω LO and RF system impedance, R1 = 432Ω,
MODULATOR OUTPUT POWER
vs. BASEBAND FREQUENCY
-5
-6
-7
fLO + f
-8
-9
-10
-11
-12
OUTPUT POWER (dBm)
-13
-14
-15
BB
fLO - f
BB
0 10203040506070
BASEBAND FREQUENCY (MHz)
P
I/Q-COMBINED
MODULATOR LO LEAKAGE
vs. LO FREQUENCY
-40
PLO = -3dBm
-50
-60
PRF = -1dBm, LO LEAKAGE NULLED
= 0dBm
AT P
LO
MODULATOR LO LEAKAGE
vs. LO FREQUENCY
PRF = -1dBm, LO LEAKAGE NULLED
= +25°C
AT T
A
TC = -40°C
TC = +85°C
TC = +25°C
1.80 1.82 1.84 1.86 1.88 1.90
LO FREQUENCY (GHz)
MODULATOR OUTPUT NOISE DENSITY
vs. OUTPUT POWER
PLO = -3dBm
PLO = 0dBm
= 0dBm
MAX2023 toc16
MAX2023 toc19
MODULATOR LO LEAKAGE
vs. LO FREQUENCY
-40
PRF = -40dBm
-50
-60
-70
PRF = -7dBm
-80
LO LEAKAGE (dBm)
-90 PRF = -1dBm
-100
1.80 1.82 1.84 1.86 1.88 1.90
PRF = +5dBm
LO LEAKAGE NULLED
= -1dBm
AT P
RF
LO FREQUENCY (GHz)
MODULATOR OUTPUT NOISE DENSITY
vs. OUTPUT POWER
-150
-155
-160
MAX2023 toc17
MAX2023 toc20
-40
-50
-60
-70
-80
LO LEAKAGE (dBm)
-90
-100
-150
-155
-160
MAX2023 toc18
MAX2023 toc21
-70
-80
LO LEAKAGE (dBm)
PLO = +3dBm
-90
-100
1.80 1.82 1.84 1.86 1.88 1.90
PLO = 0dBm
LO FREQUENCY (GHz)
DEMODULATOR CONVERSION LOSS
vs. LO FREQUENCY
12.0
11.5
11.0
10.5
10.0
9.5
CONVERSION LOSS (dB)
9.0
8.5
8.0
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
TC = +85°C
TC = +25°C
TC = -40°C
LO FREQUENCY (GHz)
-165 TC = +85°C
-170
OUTPUT NOISE DENSITY (dBm/Hz)
-175
TC = -40°C
-180
-23 -18 -13 -8 -3 2 7 12
45
43
MAX2023 toc22
41
39
37
35
33
INPUT IP3 (dBm)
31
29
27
25
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
TC = +25°C
OUTPUT POWER (dBm)
DEMODULATOR INPUT IP3
vs. LO FREQUENCY
PLO = 0dBm
PLO = +3dBm
PLO = -3dBm
f1 = fLO + 25MHz
= fLO + 26MHz
f
2
LO FREQUENCY (GHz)
-165
-170
OUTPUT NOISE DENSITY (dBm/Hz)
-175
-180
-23 -18 -13 -8 -3 2 7 12
45
43
MAX2023 toc23
41
39
37
35
33
INPUT IP3 (dBm)
31
29
27
25
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
OUTPUT POWER (dBm)
DEMODULATOR INPUT IP3
vs. LO FREQUENCY
TC = +25°C
LO FREQUENCY (GHz)
TC = -40°C
PLO = +3dBm
TC = +85°C
f1 = fLO + 25MHz
= fLO + 26MHz
f
2
MAX2023 toc24
MAX2023
High-Dynamic-Range, Direct Up-/Downconversion
1500MHz to 2300MHz Quadrature Mod/Demod
_________________________________________________________________________________________________
7
Typical Operating Characteristics (continued)
(MAX2023
Typical Application Circuit
, VCC= +4.75V to +5.25V, GND = 0V, I/Q differential inputs driven from a 100DC-coupled source
(modulator), V
BBI
= V
BBQ
= 2.6V
P-P
differential (modulator), PRF= +6dBm (demodulator), I/Q differential output drives 50differential load
(demodulator), 0V common-mode input/output, P
LO
= 0dBm, 1500MHz ≤ fLO≤ 2300MHz, 50Ω LO and RF system impedance, R1 = 432Ω,
R2 = 562, R3 = 300Ω, T
C
= -40°C to +85°C. Typical values are at VCC= +5V, fLO= 1850MHz, TC= +25°C, unless otherwise noted.)
DEMODULATOR INPUT IP2
vs. LO FREQUENCY
LO FREQUENCY (GHz)
INPUT IP2 (dBm)
MAX2023 toc25
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
50
55
60
65
70
75
80
TC = +85°C
TC = +25°C
TC = -40°C
f1 = fLO + 25MHz f
2
= fLO + 26MHz
DEMODULATOR I/Q PHASE IMBALANCE
vs. LO FREQUENCY
LO FREQUENCY (GHz)
I/Q PHASE IMBALANCE (deg)
MAX2023 toc26
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
0
1
2
3
4
5
6
PLO = -3dBm
PLO = 0dBm
PLO = +3dBm
PLO = -6dBm
DEMODULATOR I/Q AMPLITUDE IMBALANCE
vs. LO FREQUENCY
LO FREQUENCY (GHz)
I/Q AMPLITUDE IMBALANCE (dB)
MAX2023 toc27
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
PLO = -3dBm
PLO = 0dBm
PLO = +3dBm
PLO = -6dBm
LO PORT RETURN LOSS
LO FREQUENCY (GHz)
RETURN LOSS (dB)
MAX2023 toc28
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
30
28
26
24
22
20
18
16
14
12
10
PLO = -3dBm
PLO = 0dBm
PLO = +3dBm
PLO = -6dBm
RF PORT RETURN LOSS
RF FREQUENCY (GHz)
RETURN LOSS (dB)
MAX2023 toc29
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3
40
35
30
25
20
15
10
P
LO
= -6dBm, -3dBm, 0dBm, +3dBm
MAX2023
High-Dynamic-Range, Direct Up-/Downconversion 1500MHz to 2300MHz Quadrature Mod/Demod
8 ________________________________________________________________________________________________
Detailed Description
The MAX2023 is designed for upconverting differential in-phase (I) and quadrature (Q) inputs from baseband to a 1500MHz to 2300MHz RF frequency range. The device can also be used as a demodulator, downcon­verting an RF input signal directly to baseband. Applications include single and multicarrier 1500MHz to 2300MHz DCS/PCS EDGE, UMTS/WCDMA, cdma2000, and PHS/PAS base stations. Direct conversion archi­tectures are advantageous since they significantly reduce transmitter or receiver cost, part count, and power consumption as compared to traditional IF-based double-conversion systems.
The MAX2023 integrates internal baluns, an LO buffer, a phase splitter, two LO driver amplifiers, two matched double-balanced passive mixers, and a wideband quad­rature combiner. The MAX2023’s high-linearity mixers, in conjunction with the part’s precise in-phase and quadra­ture channel matching, enable the device to possess excellent dynamic range, ACLR, 1dB compression point, and LO and sideband suppression characteristics. These features make the MAX2023 ideal for single-carrier GSM and multicarrier WCDMA operation.
LO Input Balun, LO Buffer, and
Phase Splitter
The MAX2023 requires a single-ended LO input, with a nominal power of 0dBm. An internal low-loss balun at the LO input converts the single-ended LO signal to a differential signal at the LO buffer input. In addition, the internal balun matches the buffer’s input impedance to 50over the entire band of operation.
The output of the LO buffer goes through a phase split­ter, which generates a second LO signal that is shifted by 90° with respect to the original. The 0° and 90° LO signals drive the I and Q mixers, respectively.
LO Driver
Following the phase splitter, the 0° and 90° LO signals are each amplified by a two-stage amplifier to drive the I and Q mixers. The amplifier boosts the level of the LO signals to compensate for any changes in LO drive lev­els. The two-stage LO amplifier allows a wide input power range for the LO drive. The MAX2023 can toler­ate LO level swings from -3dBm to +3dBm.
Pin Description
PIN NAME FUNCTION
1, 5, 9–12, 14, 16–19, 22,
24, 27–30, 32, 34, 35, 36
2 RBIASLO3 3rd LO Amplifier Bias. Connect a 300Ω resistor to ground.
3 VCCLOA
4 LO Local Oscillator Input. 50 input impedance. Requires a DC-blocking capacitor. 6 RBIASLO1 1st LO Input Buffer Amplifier Bias. Connect a 432 resistor to ground.
7 N.C. No Connection. Leave unconnected. 8 RBIASLO2 2nd LO Amplifier Bias. Connect a 562Ω resistor to ground.
13 VCCLOI1
15 VCCLOI2
20 BBI+ Baseband In-Phase Noninverting Port 21 BBI- Baseband In-Phase Inverting Port 23 RF RF Port. This port is matched to 50. Requires a DC-blocking capacitor. 25 BBQ- Baseband Quadrature Inverting Port
26 BBQ+ Baseband Quadrature Noninverting Port
31 VCCLOQ2
33 VCCLOQ1
EP GND
GND Ground
LO Input Buffer Amplifier Supply Voltage. Bypass to GND with 22pF and 0.1µF capacitors as close to the pin as possible.
I-Channel 1st LO Amplifier Supply Voltage. Bypass to GND with 22pF and 0.1µF capacitors as close to the pin as possible. I-Channel 2nd LO Amplifier Supply Voltage. Bypass to GND with 22pF and 0.1µF capacitors as close to the pin as possible.
Q-Channel 2nd LO Amplifier Supply Voltage. Bypass to GND with 22pF and 0.1µF capacitors as close to the pin as possible.
Q-Channel 1st LO Amplifier Supply Voltage. Bypass to GND with 22pF and 0.1µF capacitors as close to the pin as possible. Exposed Ground Paddle. The exposed paddle MUST be soldered to the ground plane using multiple vias.
MAX2023
High-Dynamic-Range, Direct Up-/Downconversion
1500MHz to 2300MHz Quadrature Mod/Demod
_________________________________________________________________________________________________ 9
MAX2023
I/Q Modulator
The MAX2023 modulator is composed of a pair of matched double-balanced passive mixers and a balun. The I and Q differential baseband inputs accept signals from DC to 450MHz with differential amplitudes up to 4V
P-P
. The wide input bandwidths allow operation of the MAX2023 as either a direct RF modulator or as an image-reject mixer. The wide common-mode compli­ance range allows for direct interface with the base­band DACs. No active buffer circuitry is required between the baseband DACs and the MAX2023 for wideband applications.
The I and Q signals directly modulate the 0° and 90° LO signals and are upconverted to the RF frequency. The out­puts of the I and Q mixers are combined through a balun to produce a singled-ended RF output.
Applications Information
LO Input Drive
The LO input of the MAX2023 is internally matched to 50, and requires a single-ended drive at a 1500MHz to 2300MHz frequency range. An integrated balun con­verts the singled-ended input signal to a differential sig­nal at the LO buffer differential input. An external DC-blocking capacitor is the only external part required at this interface. The LO input power should be within the -3dBm to +3dBm range. An LO input power of 0dBm is recommended for best overall peformance.
Baseband I/Q Input Drive
Drive the MAX2023 I and Q baseband inputs differen­tially for best performance. The baseband inputs have a 50differential input impedance. The optimum source impedance for the I and Q inputs is 100Ω differ- ential. This source impedance achieves the optimal sig­nal transfer to the I and Q inputs, and the optimum output RF impedance match. The MAX2023 can accept input power levels of up to +20dBm on the I and Q inputs. Operation with complex waveforms, such as CDMA carriers or GSM signals, utilize input power lev­els that are far lower. This lower power operation is made necessary by the high peak-to-average ratios of these complex waveforms. The peak signals must be kept below the compression level of the MAX2023. The input common-mode voltage should be confined to the
-3.5V to +3.5V DC range.
WCDMA Transmitter Applications
The MAX2023 is designed to interface directly with Maxim high-speed DACs. This generates an ideal total transmitter lineup, with minimal ancillary circuit elements required for widespread applications. Such DACs include the MAX5875 series of dual DACs, and the
MAX5895 dual interpolating DAC. These DACs have ground-referenced differential current outputs. Typical termination of each DAC output into a 50load resistor to ground, and a 10mA nominal DC output current results in a 0.5V common-mode DC level into the modu­lator I/Q inputs. The nominal signal level provided by the DACs will be in the -12dBm range for a single CDMA or WCDMA carrier, reducing to -18dBm per carrier for a four-carrier application.
The I/Q input bandwidth is greater than 450MHz at
-0.5dB response. The direct connection of the DAC to the MAX2023 ensures the maximum signal fidelity, with no performance-limiting baseband amplifiers required. The DAC output can be passed through a lowpass filter to remove the image frequencies from the DAC’s output response. The MAX5895 dual interpolating DAC can be operated at interpolation rates up to x8. This has the benefit of moving the DAC image frequencies to a very high, remote frequency, easing the design of the base­band filters. The DAC’s output noise floor and interpola­tion filter stopband attenuation are sufficiently good to ensure that the 3GPP noise floor requirement is met for large frequency offsets, 60MHz for example, with no fil­tering required on the RF output of the modulator.
Figure 1 illustrates the ease and efficiency of interfacing the MAX2023 with a Maxim DAC, in this case the MAX5895 dual 16-bit interpolating-modulating DAC.
Figure 1. MAX5895 DAC Interfaced with MAX2023 for cdma2000 and WCDMA Base Stations
MAX5895
DUAL 16-BIT INTERP DAC
BBI
I/Q GAIN AND
OFFSET ADJUST
BBQ
50
FREQ
50
LO
50
FREQ
50
MAX2023
RF MODULATOR
0°
90°
MAX2023
High-Dynamic-Range, Direct Up-/Downconversion 1500MHz to 2300MHz Quadrature Mod/Demod
10 _______________________________________________________________________________________________
The MAX5895 DAC has programmable gain and differ­ential offset controls built in. These can be used to opti­mize the LO leakage and sideband suppression of the MAX2023 quadrature modulator.
GSM Transmitter Applications
The MAX2023 is an ideal modulator for a zero-IF (ZIF), single-carrier GSM transmitter. The device’s wide dynamic range enables a very efficient overall transmitter architec­ture. Figure 2 illustrates the exceptionally simple complete lineup for a high-performance GSM/EDGE transmitter.
The single-carrier GSM transmit lineup generates base­band I and Q signals from a simple 12-bit dual DAC such as the MAX5873. The DAC clock rate can be a multiple of the GSM system clock rate of 13MHz. The ground-referenced outputs of the dual DAC are filtered by simple discrete element lowpass filters to attenuate both the DAC images and the noise floor. The I and Q baseband signals are then level shifted and amplified by a MAX4395 quad operational amplifier, configured as a differential input/output amplifier. This amplifier can deliver a baseband power level of greater than +15dBm to the MAX2023, enabling very high RF output power levels. The MAX2023 will deliver up to +5dBm for GSM vectors with full conformance to the required system specifications with large margins. The excep­tionally low phase noise of the MAX2023 allows the cir-
cuit to meet the GSM system level noise requirements with no additional RF filters required, greatly simplifying the overall lineup.
The output of the MAX2023 drives a MAX2059 RF VGA, which can deliver up to +15dBm of GSM carrier power and includes a very flexible digitally controlled attenuator with over 56dB of adjustment range. This accommodates the full static and dynamic power-control requirements, with extra range for lineup gain compensation.
RF Output
The MAX2023 utilizes an internal passive mixer archi­tecture that enables the device to possess an excep­tionally low-output noise floor. With such architectures, the total output noise is typically a power summation of the theoretical thermal noise (kTB) and the noise contri­bution from the on-chip LO buffer circuitry. As demon­strated in the
Typical Operating Characteristics
, the MAX2023’s output noise approaches the thermal limit of -174dBm/Hz for lower output power levels. As the output power increases, the noise level tracks the noise contribution from the LO buffer circuitry, which is approximately -165dBc/Hz.
The I/Q input power levels and the insertion loss of the device determine the RF output power level. The input power is a function of the delivered input I and Q volt­ages to the internal 50termination. For simple sinu-
Figure 2. Complete Transmitter Lineup for GSM/EDGE DCS/PCS-Band Base Stations
MAX5873
DUAL DAC
I
12
Q
12
MAX4395
QUAD AMP
MAX2021/MAX2023
0°
90°
VCO + SYNTH
MAX9491
MAX2058/MAX2059
RF DIGITAL VGAs
31dB
45, 80,
OR
95MHz LO
17dB
LOOPBACK
OUT
(FEEDS BACK
INTO Rx CHAIN
FRONT-END)
OFF
Rx
31dB
SPI
LOGIC
SPI
CONTROL
RFOUT
MAX2023
High-Dynamic-Range, Direct Up-/Downconversion
1500MHz to 2300MHz Quadrature Mod/Demod
________________________________________________________________________________________________ 11
soidal baseband signals, a level of 89mV
P-P
differential on the I and the Q inputs results in a -17dBm input power level delivered to the I and Q internal 50termi­nations. This results in an RF output power of -26.6dBm.
External Diplexer
LO leakage at the RF port can be nulled to a level less than -80dBm by introducing DC offsets at the I and Q ports. However, this null at the RF port can be compro­mised by an improperly terminated I/Q IF interface. Care must be taken to match the I/Q ports to the driving DAC circuitry. Without matching, the LO’s second-order (2fLO) term may leak back into the modulator’s I/Q input port where it can mix with the internal LO signal to produce additional LO leakage at the RF output. This leakage effectively counteracts against the LO nulling. In addi­tion, the LO signal reflected at the I/Q IF port produces a residual DC term that can disturb the nulling condition.
As demonstrated in Figure 3, providing an RC termination on each of the I+, I-, Q+, Q- ports reduces the amount of LO leakage present at the RF port under varying temper­ature, LO frequency, and baseband termination condi­tions. See the
Typical Operating Characteristics
for details. Note that the resistor value is chosen to be 50 with a corner frequency 1 / (2πRC) selected to adequate­ly filter the fLOand 2fLOleakage, yet not affecting the flat­ness of the baseband response at the highest baseband frequency. The common-mode fLOand 2fLOsignals at I+/I- and Q+/Q- effectively see the RC networks and thus
become terminated in 25(R/2). The RC network pro­vides a path for absorbing the 2f
LO
and fLOleakage, while the inductor provides high impedance at fLOand 2f
LO
to help the diplexing process.
RF Demodulator
The MAX2023 can also be used as an RF demodulator, downconverting an RF input signal directly to base­band. The single-ended RF input accepts signals from 1500MHz to 2300MHz with power levels up to +30dBm. The passive mixer architecture produces a conversion loss of typically 9.5dB. The downconverter is optimized for high linearity and excellent noise performance, typi­cally with a +38dBm IIP3, an input P1dB of +29.7dBm, and a 9.6dB noise figure.
A wide I/Q port bandwidth allows the port to be used as an image-reject mixer for downconversion to a quadra­ture IF frequency.
The RF and LO inputs are internally matched to 50Ω. Thus, no matching components are required, and only DC-blocking capacitors are needed for interfacing.
Power Scaling with Changes
to the Bias Resistors
Bias currents for the LO buffers are optimized by fine tuning resistors R1, R2, and R3. Maxim recommends using ±1%-tolerant resistors; however, standard ±5% values can be used if the ±1% components are not readily available. The resistor values shown in the
Typical Application Circuit
were chosen to provide peak performance for the entire 1500MHz to 2300MHz band. If desired, the current can be backed off from this nominal value by choosing different values for R1, R2, and R3. Contact the factory for additional details.
Layout Considerations
A properly designed PC board is an essential part of any RF/microwave circuit. Keep RF signal lines as short as possible to reduce losses, radiation, and induc­tance. For the best performance, route the ground pin traces directly to the exposed paddle under the pack­age. The PC board exposed paddle MUST be connect­ed to the ground plane of the PC board. It is suggested that multiple vias be used to connect this paddle to the lower level ground planes. This method provides a good RF/thermal conduction path for the device. Solder the exposed paddle on the bottom of the device pack­age to the PC board. The MAX2023 evaluation kit can be used as a reference for board layout. Gerber files are available upon request at www.maxim-ic.com.
Figure 3. Diplexer Network Recommended for DCS 1800/ PCS 1900 EDGE Transmitter Applications
I
Q
C = 2.2pF
MAX2023
RF MODULATOR
0°
90°
L = 11nH
L = 11nH
C = 2.2pF
C = 2.2pF
50
50
LO
50
50
MAX2023
Power-Supply Bypassing
Proper voltage-supply bypassing is essential for high­frequency circuit stability. Bypass all VCC_ pins with 22pF and 0.1µF capacitors placed as close to the pins as possible, with the smallest capacitor placed closest to the device.
To achieve optimum performance, use good voltage­supply layout techniques. The MAX2023 has several RF processing stages that use the various VCC_ pins, and while they have on-chip decoupling, off-chip interaction between them may degrade gain, linearity, carrier sup­pression, and output power-control range. Excessive coupling between stages may degrade stability.
Exposed Paddle RF/Thermal Considerations
The EP of the MAX2023’s 36-pin thin QFN-EP package provides a low thermal-resistance path to the die. It is important that the PC board on which the IC is mounted be designed to conduct heat from this contact. In addi­tion, the EP provides a low-inductance RF ground path for the device.
The exposed paddle (EP) MUST be soldered to a ground plane on the PC board either directly or through an array of plated via holes. An array of 9 vias, in a 3 x 3 array, is suggested. Soldering the pad to ground is critical for efficient heat transfer. Use a solid ground plane wherever possible.
High-Dynamic-Range, Direct Up-/Downconversion 1500MHz to 2300MHz Quadrature Mod/Demod
12 _______________________________________________________________________________________________
Pin Configuration/Functional Diagram
GND
36
GND
1
VCCLOA
GND
N.C.
GND
2
3
4
LO
5
6
7
8
9
RBIASLO3
RBIASLO1
RBIASLO2
34
BIAS
LO3
BIAS
LO1
BIAS
LO2
GND
VCCLOQ1
33 32
90°
GND
35
VCCLOQ2
GND
31
0°
GND
30 29
MAX2023
Σ
GND
GND
28
27
GND
26
BBQ+
25
BBQ-
24
GND
23
RF
22
GND
BBI-
21
20
EP
BBI+
19
GND
10
GND
11 12
GND
GND
13 14
GND
VCCLOI1
THIN QFN
15
VCCLOI2
16 17
GND
GND
18
GND
MAX2023
High-Dynamic-Range, Direct Up-/Downconversion
1500MHz to 2300MHz Quadrature Mod/Demod
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________
13
© 2006 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.
MAX2023
1
2
3
4
5
6
7
8
9
10
11 12
13 14 15
16 17
18
27
26
25
24
23
22
21
20
19
36
35
34
33 32
31
30 29
28
Σ
BIAS
LO2
BIAS
LO1
90°
0°
BIAS LO3
GND
BBI+
BBI-
GND
RF
RF
GND
BBQ-
BBQ+
Q+
Q-
GND
I-
I+
C9
2pF
C8
0.1µF
V
CC
C7 22pF
C5
0.1µF
C6
22pF
V
CC
GND
GND
GND
GND
VCCLOI1
VCCLOI2
GND
GND
GND
EP
GND
GND
RBIASLO3
R3
300
C1 22pF
C3 8pF
LO
C2
0.1µF
V
CC
VCCLOA
LO
GND
RBIASLO1
R1
432
N.C.
RBIASLO2
C11
0.1µF V
CC
C10 22pF
C12
0.1µF
C13
22pF
V
CC
GND
GND
GND
VCCLOQ2
GND
GND
GND
GND
MAX2023
VCCLOQ1
R2
562
Typical Application Circuit
Table 1. Component List Referring to the Typical Application Circuit
Package Information
For the latest package outline information, go to www.maxim-ic.com/packages
.
Chip Information
PROCESS: SiGe BiCMOS
JACKSON
COMPONENT VALUE DESCRIPTION
C1, C6, C7, C10, C13 22pF 22pF ±5%, 50V C0G ceramic capacitors (0402)
C2, C5, C8, C11, C12 0.1µF 0.1µF ±10%, 16V X7R ceramic capacitors (0603)
C3 8pF 8pF ±0.25%, 50V C0G ceramic capacitor (0402)
C9 2pF 2pF ±0.1pF, 50V C0G ceramic capacitor (0402)
R1 432 432 ±1% resistor (0402)
R2 562 562 ±1% resistor (0402)
R3 300 300 ±1% resistor (0402)
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