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DEFINITION OF SPECIFICATIONS

Unadjusted Carrier Feedthrough

Adjusted (Optimized) Carrier Feedthrough

Unadjusted Sideband Suppression

Adjusted (Optimized) Sideband Suppression

Suppressions Over Temperature

f − Frequency Offset − kHz (Relative to Carrier)

−80

−70

−60

−50

−40

−30

−20

−10

0

10

−200 −150 −100

−50

0

50

100

150

200

G024

(dBc)

LSB

(Undesired)

SBS

(dBc)

Carrier

USB

(Desired)

(dBc)

C

(dBm)

TRF3703

SLWS184D – MARCH 2006 – REVISED JUNE 2007

This specification measures the amount by which the local oscillator component is attenuated in the output

spectrum of the modulator relative to the carrier. This further assumes that the baseband inputs delivered to the

pins of the TRF3703 are perfectly matched to have the same dc offset (VCM). This includes all four baseband

inputs: I, I, Q, and Q. This is measured in dBm.

This differs from the unadjusted suppression number in that the baseband input dc offsets are iteratively

adjusted around their theoretical value of VCM to yield the maximum suppression of the LO component in the

output spectrum. This is measured in dBm.

This specification measures the amount by which the unwanted sideband of the input signal is attenuated in the

output of the modulator, relative to the wanted sideband. This further assumes that the baseband inputs

delivered to the modulator input pins are perfectly matched in amplitude and are exactly 90

° out of phase. This

is measured in dBc.

This differs from the unadjusted sideband suppression in that the baseband inputs are iteratively adjusted

around their theoretical values to maximize the amount of sideband suppression. This is measured in dBc.

This specification assumes that the user has gone though the optimization process for the suppression in

question, and set the optimal settings for the I, Q inputs. This specification then measures the suppression when

temperature conditions change after the initial calibration is done.

Figure 26 shows a simulated output and illustrates the respective definitions of various terms used in this data

sheet. The graph assumes a baseband input of 50 kHz.

Figure 26. Graphical Illustration of Common Terms

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