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5v, t, 25°c) – Rainbow Electronics MAX2684 User Manual

Page 13

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MAX2683/MAX2684

3.5GHz Downconverter Mixers

with Selectable LO Doubler

______________________________________________________________________________________

13

(VCO) from the PA, and reducing the demands of
designing a high-frequency VCO. An internal LO band-
pass filter is integrated after the frequency doubler to
help reduce LO harmonic content and spurious mixing.

To enable the LO frequency doubler, drive ENX2 to a
logic-low level and connect the half-frequency external
LO to the LOX2 port. To disable and bypass the LO fre-
quency doubler and LO filter, drive ENX2 to a logic-
high level and connect the full-frequency external LO to

1800

0.254

-98.9

3600

0.271

-164.9

1875

0.262

LOX1

(ENX2 = V

CC

)

LOX2

FREQUENCY

(MHz)

S11 MAG

S11 PHASE

(degrees)

3450

0.306

-167.3

3300

0.338

-167.0

3150

0.358

-165.4

3000

0.362

-163.5

LOX2

(ENX2 = GND)

LOX2

FREQUENCY

(MHz)

S11 MAG

S11 PHASE

(degrees)

1725

0.247

-95.3

1650

0.241

-91.1

1575

0.237

-86.7

1500

0.234

-82.0

-102.3

3750

0.235

-160.6

1950

0.268

-104.9

3900

0.200

-154.8

1500

0.211

-77.9

3000

0.343

-159.1

1575

0.213

-83.7

3150

0.341

-160.0

1650

0.217

-89.3

3300

0.330

-162.3

1725

0.222

-94.5

3450

0.310

-162.0

1800

0.230

-99.3

3600

0.285

-160.2

1875

0.240

-103.6

3750

0.256

-156.4

1950

0.249

-107.1

3900

0.224

-151.1

1500

0.213

-78.0

3000

0.339

-155.2

1575

0.214

-83.7

3150

0.340

-156.0

1650

0.218

-89.3

3300

0.332

-156.0

1725

0.223

-94.5

3450

0.315

-155.3

1800

0.231

-99.3

3600

0.294

-153.3

1875

0.241

-103.7

3750

0.268

-150.0

1950

0.249

-107.2

3900

0.240

-145.5

R

BIAS

= 820

R

BIAS

= 1.2k

R

BIAS

= 2.0k

Table 2. MAX2683 LO Port S-Parameters (V

CC

= +5V, T

A

= +25°C)