AD9863

Rev. A| Page 16 of 40

Figure 40 to Figure 45 use the same input data to the Tx path, a 256-carrier OFDM signal over a 23 MHz bandwidth, centered at 23 MHz.

The four center carriers are removed from the signal to observe the in-band intermodulation distortion (IMD) from the DAC output.

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9

141924

34

29

FREQUENCY (MHz)

Figure 40. AD9863 Tx Path FFT, 256-Carrier (Four Center Carriers Removed)

OFDM Signal over 23 MHz Bandwidth, Centered at 7 MHz, with

20 mA Full-Scale Output into 60 Ω Differential Load

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10.5

10.7

10.9

11.1

11.3

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11.7

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12.1

12.3

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FREQUENCY (MHz)

Figure 41. AD9863 Tx Path FFT, Lower-Band IMD Products of

OFDM Signal in Figure 40

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60708090

FREQUENCY (MHz)

Figure 42. AD9863 Tx Path FFT of OFDM Signal in Figure 40,

with 1× Interpolation

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6.97

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FREQUENCY (MHz)

Figure 43. AD9863 Tx Path FFT, In-Band IMD Products of

OFDM Signal in Figure 40

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33.7

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35.3

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FREQUENCY (MHz)

Figure 44. AD9863 Tx Path FFT, Upper-Band IMD Products of

OFDM Signal in Figure 40

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FREQUENCY (MHz)

Figure 45. AD9863 Tx Path FFT of OFDM Signal in Figure 40,

with 2× Interpolation