Data Sheet

ADL6317

Rev. B | Page 21 of 38

APPLICATIONS INFORMATION

LINEARITY OPTIMIZATION

The linearity in the ADL6317 can be optimized through

the TRM_AMP2_IP3 (Register 0x11B, Bits[1:0]) and

TRM_AMP2_CB (Register 0x10B, Bits[1:0]) settings. Set the

IP3_OFF bit (Register 0x101, Bit 1) 0x00 for OIP3

optimization. The TRM_AMP2_IP3 bits control the switches in

the second amplifier that enables optimal third-order distortion

cancellation and optimal OIP3. The TRM_AMP2_CB bits

control the common base bias current on the transistor and

allows additional linearity optimization.

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

FREQUENCY (MHz)

TRM_AMP2_IP3 = 0

TRM_AMP2_IP3 = 1

TRM_AMP2_IP3 = 2

TRM_AMP2_IP3 = 3

Figure 43. OIP3 vs. RF Frequency for Various TRM_AMP2_IP3 Settings,

TRM_AMP2_CB = 0x02, TRM_AMP1_IREF_x and TRM_AMP2_IREF_x = 0x02

Figure 43 shows that the OIP3 is optimizable across the

TRM_AMP2_IP3 settings.

Figure 43 shows better than 1.5 dB OIP3 improvement that

correlates to 3 dB improvement on IMD3 performance at

below 1.9 GHz through linearity optimization.

PERFORMANCE AND POWER OPTIMIZATION

The ADL6317 provides another level of control to optimize

power or performance. In applications where performance is

critical, the ADL6317 offers performance optimization at the

expense of power consumption. However, if low power is the

priority, the ADL6317 offers tuning options in the amplifier

blocks of the chip to further reduce power consumption.

Table 20 shows that the potential power optimization vs.

performance can fine tune the reference current on RF

amplifier settings.

ADJACENT AND ALTERNATE CHANNEL POWER

RATIOS ON LTE OPERATION

Figure 44 shows the adjacent and alternate channel power

ratios (CPR) for the ADL6317 using 5 MHz single-carrier LTE.

The adjacent CPR is −70.4 dB and the alternative CPR is

−72.9 dB at an RF of 1850 MHz. The adjacent and alternate CPR

performance varies over output power. On the ADL6317, the

output power can be varied by adjusting the input power, the

VVA attenuation, or the DSA attenuation. Figure 45 to Figure 47

show the adjacent and alternate CPR performance vs. output

power for the different methods of controlling the ADL6317.

As shown in Figure 45, the optimum adjacent and alternate

CPR can be achievable at an output power of +8 dBm, which

corresponds to an input power of −24.6 dBm driving the ADL6317

where the internal VVA is set to 0 dB, and the DSA is set to

0 dB attenuation. Figure 46 and Figure 47 show adjacent and

alternate CPR performance vs. output power that is adjusted by

VVA attenuation and by DSA attenuation, respectively, with

−17.2 dBm of input power. Figure 45 to Figure 47 show below

−65 dB adjacent and alternate CPR performance at below

+10 dBm output power, and there is gradual degradation above

+10 dBm from the contribution to the adjacent and alternate

CPR performance of the second stage RF amplifier. When

fixing the VVA attenuation and sweeping the DSA, the

adjacent and alternate CPR performance remains constant

below 6 dBm output power (see Figure 47).

Table 20. Power Optimization vs. Performance at 1850 MHz, VVA Attenuation= 0 dB, DSA Attenuation = 0 dB, TRM_AMP2_IP3 = 0x02

TRM_AMPx_IREF_1 Setting (Decimal),

Register 0x117 and Register 0x119, Bits[3:0]

DC Power (W)

Gain (dB)

OP1dB (dBm)

OIP3 (dBm)

NF (dB)

3

2.36

33.1

25.8

40.3

6.6

2

2.10

33.1

25.6

40.3

5.9

1

1.84

33.1

25.1

39.2

5.8

0

1.55

32.8

24.3

36.9

5.8