Si4021

11

Modulated RF Spectrum

At 433 MHz with

180 kHz Deviation at 64 kbps

At 868 MHz with

180 kHz Deviation at 64 kbps

17:11:41 Dec 7, 2005

Ref 10 dBm

Atten 20 dB

#Samp

Log

10

dB/

VAv g

24

W1 S2

S3 FC

AA

Center 434 MHz

#Res BW 1 kHz

#VBW 1 kHz

Span 2 MHz

Sw eep 4.074 s (2000 pts)

17:26:17 Dec 7, 2005

Ref 10 dBm

Atten 20 dB

#Samp

Log

10

dB/

VAv g

50

W1 S2

S3 FC

AA

Center 868 MHz

#Res BW 1 kHz

#VBW 1 kHz

Span 2 MHz

Sw eep 4.074 s (2000 pts)

Spurious RF Spectrum

With 10 MHz CLK Output Enabled at 433 MHz

Antenna Tuning Characteristics

750–970 MHz

17:18:23 Dec 7, 2005

Ref 10 dBm

Atten 20 dB

Mkr1

 19.98 MHz

-44.23 dB

#Peak

Log

10

dB/

VAv g

3

W1 S2

S3 FC

AA

Center 434 MHz

#Res BW 3 kHz

#VBW 300 Hz

Span 50 MHz

Sw eep 45.47 s (2000 pts)

1

1 R

The antenna tuning characteristics was recorded in “max-hold” state of the spectrum analyzer. During the measurement, the transmitters

were forced to change frequencies by forcing an external reference signal to the XTL pin. While the carrier was changing the antenna tuning

circuit switched trough all the available states of the tuning circuit. The graph clearly demonstrates that while the complete output circuit

had about a 40 MHz bandwidth, the tuning allows operating in a 220 MHz band. In other words, the tuning circuit can compensate for 25%

variation in the resonant frequency due to any process or manufacturing spread.