ADRF6612ACPZ-R7 datasheet(37/57 Pages) AD

37 / 57 page

Data Sheet

ADRF6612

Rev. A | Page 37 of 57

MIXER OPTIMIZATION

RF INPUT BALUN INSERTION LOSS OPTIMIZATION

At lower input frequencies, more capacitance is needed. This

increase is achieved by programming higher codes into

BAL_COUT. At high frequencies, less capacitance is required;

therefore, lower BAL_COUT codes are appropriate.

As shown in Figure 96 and Figure 97, this tuning range can be

further optimized by adding capacitance across the RF input in

conjunction with tuning BAL_COUT. This can help to increase

the low frequency range of the device significantly.

–20

–18

–16

–14

–12

–10

–8

–6

–4

–2

500

900

1300

1700

2100

2500

2900

RF FREQUENCY (MHz)

NO CAP

1pF

2pF

3.3pF

4pF

5.6pF

6.8pF

Figure 96. Return Loss; Optimum COUT vs. Tuning Capacitor on RFIN Using a

High Side LO

–20

–18

–16

–14

–12

–10

–8

–6

–4

–2

500

900

1300

1700

2100

2500

2900

RF FREQUENCY (MHz)

NO CAP

1pF

2pF

3.3pF

4pF

5.6pF

6.8pF

Figure 97. Return Loss; Optimum COUT vs. Tuning Capacitor on RFIN Using a

Low Side LO

IIP3 OPTIMIZATION

In applications in which performance is critical, the ADRF6612

offers IIP3 optimization. The IF amplifier bias current can be

reduced to trade performance vs. power consumption. This saves

on the overall power at the expense of degraded performance.

Figure 98 to Figure 101 show the IIP3 sweeps for all combinations

of IFA main bias and linearity bias. The IIP3 vs. IFA main bias and

linearity bias figures show both a surface and a contour plot in one

figure. The contour plot is located directly underneath the surface

plot. The best approach for reading the figure is to localize the

peaks on the surface plot, which indicate maximum IIP3, and to

follow the same color pattern to the contour plot to determine the

optimized IFA main bias and linearity bias settings.

IFA_MAIN

IFA_LIN = 0

IFA_LIN = 1

IFA_LIN = 2

IFA_LIN = 3

IFA_LIN = 4

IFA_LIN = 5

IFA_LIN = 6

IFA_LIN = 7

IFA_LIN = 8

IFA_LIN = 9

IFA_LIN = 10

IFA_LIN = 11

IFA_LIN = 12

IFA_LIN = 13

IFA_LIN = 14

Figure 98. IIP3 vs. Main (IFA_MAIN) and Linearity Bias (IFA_LIN) Level

at IF Frequency = 50 MHz

IFA_MAIN

IFA_LIN = 0

IFA_LIN = 1

IFA_LIN = 2

IFA_LIN = 3

IFA_LIN = 4

IFA_LIN = 5

IFA_LIN = 6

IFA_LIN = 7

IFA_LIN = 8

IFA_LIN = 9

IFA_LIN = 10

IFA_LIN = 11

IFA_LIN = 12

IFA_LIN = 13

IFA_LIN = 14

Figure 99. IIP3 vs. Main (IFA_MAIN) and Linearity Bias (IFA_LIN) Level

at IF Frequency = 100 MHz

IFA_MAIN

IFA_LIN = 0

IFA_LIN = 1

IFA_LIN = 2

IFA_LIN = 3

IFA_LIN = 4

IFA_LIN = 5

IFA_LIN = 6

IFA_LIN = 7

IFA_LIN = 8

IFA_LIN = 9

IFA_LIN = 10

IFA_LIN = 11

IFA_LIN = 12

IFA_LIN = 13

IFA_LIN = 14

Figure 100. IIP3 vs. Main (IFA_MAIN) and Linearity Bias (IFA_LIN) Level

at IF Frequency = 150 MHz

ADRF6612ACPZ-R7 Arkusz danych(PDF) 37 Page - Analog Devices

ADRF6612ACPZ-R7 Arkusz danych(HTML) 37 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57

Arkusz danych Pobierz

Link URL