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dc2091afa

DEMO MANUAL DC2091A

Description

LTC5599

30MHz to 1300MHz Low Power

Direct Quadrature Modulator

Demonstration circuit 2091A is optimized for evaluation

of the LTC®5599 low power direct quadrature modulator.

The balanced I and Q baseband input ports can be either

AC- or DC-coupled to a source with a common mode volt-

age level of about 1.4V. Fixed LC networks on the LO and

RF ports cover a continuous 90MHz to 1300MHz range.

The SPI interface controls the supply current, modulator

L

, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and

QuikEval is a trademark of Linear Technology Corporation. All other trademarks are the property

of their respective owners.

gain,andallowsoptimizationoftheLOcarrierfeedthrough

and side-band suppression.

Design files for this circuit board are available at

http://www.linear.com/demo/DC2091A

MeasureMent setup

Figure 1. Test Setup for RF Performance Measurements

I+

I–

Q+

Q–

DC2091 F01

BB SIGNAL SOURCE

(VCMBB = 1.4VDC)

SPECTRUM

ANALYZER

LO SIGNAL

SOURCE

DC POWER SUPPLY

(3.3V)

–

+

–3dB

–6dB