Circuit Note

CN-0518

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Rev. 0 | 3 of 8

Figure 5. ADG901 Isolation Loss Performance at OFF State

Combining the insertion loss from the filter, coupler, and the RF

switch results in a total insertion loss of approximately 3.9 dB at the

output of the RF switch in normal operating conditions.

RF PERFORMANCE

The resulting S-parameters, phase noise measurements, spurious-

free dynamic range (SFDR), noise figure, and stability measure of

the CN0518 are shown in the figures below.

At the center frequency of 915 MHz, the CN0518 achieves a gain

of 25 dB with input and output return losses of greater than 10 dB.

Figure 6 shows the S-Parameters across the operating frequency

range.

Figure 6. CN0518 S-Parameters vs. Frequency

Figure 7 shows the single sideband phase noise at 915 MHz, with

approximately -91 dBc/Hz, -125 dBc/Hz, -129 dBc/Hz, and -142

dBc/Hz at frequency offsets of 10 Hz, 1 kHz, 100 kHz, and 1 MHz

offset, respectively.

Figure 7. CN0518 Single Sideband Phase Noise at 915 MHz

Figure 8 shows the narrow-band single-tone RF output with an

SFDR of 76 dBFS.

Figure 8. CN0518 Narrow-Band Single Tone RF Output

Figure 9 shows the corresponding noise figure of approximately 0.8

dB over the entire frequency range.

Figure 9. CN0518 Noise Figure vs. Frequency

The system is stable across the entire 915 MHz ISM frequency

bandwidth with the Rollet's stability factor (k) being above 1 and the