AN307

Rev. 0.2

7

4.4. Suburban/Weak Signal Environment

Figure 5 shows three RPS spectra measured at a suburban location where many stations are attenuated by

distance and landscape features. This location is much closer to the transmission source for 98.9 MHz. This

situation is a good representation of a suburban area with mostly weak stations. Using the minimum average RNL

method with the filter size set to five channels to select candidate stations, two out of five showed good

performance with the Si4712 positioned on the dashboard, while the others were marginal. Even when manually

searching for stations, no more than two candidates with good performance could be found. Repeating the

procedure with the Si4712 on the passenger seat yielded three out of five good candidate stations and two

acceptable.

Figure 5. Si4712 RPS Station Scan Results in a Suburban/Weak Signal Environment

Table 1. RPS Candidate Station Qualitative Performance Summary

Signal Environment

Si4712 Location

RPS Selection Subjective

Performance

Good

Acceptable

Poor

Strong

Dashboard

4

0

1

Passenger Seat

3

0

2

Urban/Moderate

Dashboard

3

2

0

Passenger Seat

2

2

1

Suburban/Weak

Dashboard

2

3

0

Passenger Seat

3

2

0

Suburban/Weak Signal Environm ent

0

10

20

30

40

50

60

70

8750

9250

9750

10250

10750

Dashboard (Scan 1)

Good (Scan 1)

Acceptable (Scan 1)

Poor (Scan 1)

Passenger Seat (Scan 2)

Good (Scan 2)

Acceptable (Scan 2)

Poor (Scan 2)

Search Band Boundary