Datasheet MAX2023 Datasheet (MAXIM)

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)