
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 Range
Scalable 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 Leakage
48dBc Typical Sideband Suppression
-165dBc/Hz Output Noise Density
Broadband 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 IP1dB
9.5dB Typical Conversion Loss
9.6dB Typical NF
0.025dB Typical I/Q Gain Imbalance
0.56° 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 100Ω differential, LO input terminat-
ed into 50Ω, RF output terminated into 50Ω, 0V common-mode input, R1 = 432Ω, R2 = 562Ω, 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 100Ω DC-coupled source, 0V common-mode input, 50Ω LO and RF system impedance, R1 = 432Ω, R2 = 562Ω,
R3 = 300Ω, 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 Ω
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, 50Ω LO and RF system
impedance, R1 = 432Ω, R2 = 562Ω, R3 = 300Ω, 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 100Ω DC-coupled source, 0V common-mode input, 50Ω LO and RF system impedance, R1 = 432Ω, R2 = 562Ω,
R3 = 300Ω, 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
50Ω
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 100Ω DC-coupled source
(modulator), V
BBI
= V
BBQ
= 2.6V
P-P
differential (modulator), PRF= +6dBm (demodulator), I/Q differential output drives 50Ω differential load
(demodulator), 0V common-mode input/output, P
LO
= 0dBm, 1500MHz ≤ fLO≤ 2300MHz, 50Ω LO and RF system impedance, R1 = 432Ω,
R2 = 562Ω, 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 50Ω. 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 100Ω DC-coupled source
(modulator), V
BBI
= V
BBQ
= 2.6V
P-P
differential (modulator), PRF= +6dBm (demodulator), I/Q differential output drives 50Ω differential 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 100Ω DC-coupled source
(modulator), V
BBI
= V
BBQ
= 2.6V
P-P
differential (modulator), PRF= +6dBm (demodulator), I/Q differential output drives 50Ω differential 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 100Ω DC-coupled source
(modulator), V
BBI
= V
BBQ
= 2.6V
P-P
differential (modulator), PRF= +6dBm (demodulator), I/Q differential output drives 50Ω differential load
(demodulator), 0V common-mode input/output, P
LO
= 0dBm, 1500MHz ≤ fLO≤ 2300MHz, 50Ω LO and RF system impedance, R1 = 432Ω,
R2 = 562Ω, 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
50Ω over 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. 50Ω input impedance. Requires a DC-blocking capacitor.
6 RBIASLO1 1st LO Input Buffer Amplifier Bias. Connect a 432Ω 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 50Ω. 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
50Ω, 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 50Ω differential 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 50Ω load 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
50Ω
FREQ
50Ω
LO
50Ω
FREQ
50Ω
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 50Ω termination. 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 50Ω terminations. 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 50Ω
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 25Ω (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
50Ω
50Ω
LO
50Ω
50Ω

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
300Ω
C1
22pF
C3
8pF
LO
C2
0.1µF
V
CC
VCCLOA
LO
GND
RBIASLO1
R1
432Ω
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
562Ω
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 432Ω 432Ω ±1% resistor (0402)
R2 562Ω 562Ω ±1% resistor (0402)
R3 300Ω 300Ω ±1% resistor (0402)