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Figure 5. Magnitude Response of Sinc4/16 Filter in RDS Band

7.4 RDS Bandpass Filter and Interpolator

The 8th order digital RDS bandpass filter is of type Tschebyscheff and centered at 57 kHz. With linear phase

characteristics in the passband and approximately flat group delay it guarantees best filter function of the RDS

and ARI signal. Four biquads are cascaded working at a common sampling frequency of XTI/2/16.

Figure 6. Transfer Function of RDS Bandpass Filter

5.4

5.5

5.6

5.7

5.8

5.9

6

x 10

4

5

4.5

4

3.5

3

2.5

2

1.5

1

0.5

0

Sinc4/16 Transfer Function (RDS Band)

Frequency [Hz]

4

4.5

5

5.5

6

6.5

7

x 10

4

100

90

80

70

60

50

40

30

20

10

0

10

Transfer Function of RDS Filter

Frequency [Hz]