Data Sheet

ADL5320

OPTIMIZING OP1dB

In some applications, power handling (P1dB) is a more

important parameter than IP3. In such cases, it is possible to

retune the output load to increase the compression point of the

ADL5320. Table 10 shows the performance of the ADL5320

after tuning the output load for higher OP1dB. Table 11 lists the

component spacing, and Table 12 lists the component values.

Table 10. OP1dB, Gain, and IP3 Results with Optimized OP1dB

Frequency (MHz)

Gain (dB)

OIP3 (dBm)

OP1dB (dBm)

880

17.9

36

28.5

2140

13.5

40

28

2600

12.4

35

28.2

Table 11. Matching Component Spacing for Optimized OP1dB

Frequency (MHz)

λ1 (mils)

λ2 (mils)

λ3 (mils)

λ4 (mils)

800 to 960

200

75

339

100

2110 to 2170

300

75

89

275

2500 to 2700

142

75

89

75

1

2

(2)

3

ADL5320

C6 10µF

C5 10nF

VSUP

GND

Figure 39. Component Values and Spacing for Increased OP1dB

W-CDMA ACPR PERFORMANCE

Figure 40 shows a plot of adjacent channel power ratio (ACPR)

W-CDMA carrier (Test Model 1−64) at 2140 MHz. This signal

is generated by a very low ACPR source. ACPR is measured at

the output by a high dynamic range spectrum analyzer, which

incorporates an instrument noise correction function.

The ADL5320 achieves an ACPR of −80 dBc at 0 dBm output,

at which point device noise and not distortion is beginning to

dominate the power in the adjacent channels. At an output

power of 10 dBm, ACPR is still very low at −70 dBc, making the

device particularly suitable for PA driver applications.

–90

–80

–70

–60

–50

–40

–30

–20

–20

–15

–10

–5

0

5

10

15

20

SOURCE

Figure 40. ACPR vs. POUT, Single Carrier W-CDMA (Test Model 1−64) at

2140 MHz Evaluation Board

Table 12. Matching Component Values for Optimized OP1dB

Frequency (MHz)

C1 (pF)

C2 (pF)

C3 (pF)

C4 (pF)

C5 (nF)

C6 (μF)

C7 (pF)

L1 (nH)

800 to 960

47

47

6.8

100

10

10

5.6

47

2110 to 2170

22

22

0.5

22

10

10

1.8

15

2500 to 2700

12

1.0

1.8

12

10

10

1.0

15

Rev. B | Page 15 of 20