ADL5330

Rev. A | Page 18 of 24

WCDMA TRANSMIT APPLICATION

Figure 43 shows a plot of the output spectrum of the ADL5330

transmitting a single-carrier WCDMA signal (Test Model 1-64

at 2140 MHz). The carrier power output is approximately

−9.6 dBm. The gain control voltage is equal to 1.4 V giving a

gain of approximately 14.4 dB. At this power level, an adjacent

channel power ratio of −65.61 dBc is achieved. The alternate

channel power ratio of −71.37 dBc is dominated by the noise

floor of the ADL5330.

SPAN 24.6848MHz

CENTER 2.14GHz

2.46848MHz/

A

1RM

EXT

–20

–40

–50

–30

–60

–70

–80

–90

–100

–110

–120

1 AVG

1 [T1]

–29.78 dBm

2.13996994 GHz

CH PWR

–9.56 dBm

ACP Up

–66.30 dB

ACP Low

–65.61 dB

ALT1 Up

–71.37 dB

ALT1 Low

–72.79 dB

0.4 dB OFFSET

CL2

CL2

CL1

CL1

C0

C0

CU1

CU1

CU2

CU2

REF LVL

–20dBm

–29.78dBm

2.13996994GHz

MARKER 1 [T1]

RBW

VBW

SWT

30kHz

300kHz

100ms

RF ATT

UNIT

0dB

dBm

Figure 43. Single-Carrier WCDMA Spectrum at 2140 MHz;

Figure 44 shows how ACPR and noise vary with different input

power levels (gain control voltage is held at 1.4 V). At high

power levels, both adjacent and alternate channel power ratios

sharply increase. As output power drops, adjacent and alternate

channel power ratios both reach minima before the measure-

ment becomes dominated by the noise floor of the ADL5330. At

this point, adjacent and alternate channel power ratios become

approximately equal.

As the output power drops, the noise floor, measured in dBm/

Hz at 50 MHz carrier offset, initially falls and then levels off.

–90

–50

–55

–60

–65

–70

–75

–80

–85

OUTPUT POWER (dBm)

10

–40

–35

–30

–25

–20

–15

–10

–5

0

5

–20

–30

–40

–50

–60

–70

–80

–90

–100

ACPR +5MHZ OFFSET

ACPR +10MHZ

OFFSET

NOISE –50MHz OFFSET

Figure 44. ACPR and Noise vs. Output Power; Single-Carrier

Figure 45 shows how output power, ACPR, and noise vary with

input power is held constant at −19 dBm.

–100

–20

–30

–40

–50

–60

–70

–80

–90

1.4

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

10

0

–10

–20

–30

–40

–50

–60

–70

NOISE –50MHz OFFSET

OUTPUT POWER

ACPR 5MHz

ACPR 10MHz

Single-Carrier WCDMA (Test Model 1-64 at 2140 MHz) Input at −19 dBm