Standby

Standby mode is achieved by disconnecting BIAS as

shown in Figure 1. Avoid capacitance at the BIAS pin

by connecting the bias resistor from BIAS to the switch.

Layout Issues

A properly designed PC board is essential to any

RF/microwave circuit. Use controlled impedance lines

on all high-frequency inputs and outputs. Bypass with

additional decoupling capacitors. These additional

capacitors can be located farther away from the device

package. Proper grounding of the GND pins is essen-

tial. If the PC board uses a topside RF ground, connect

it directly to all GND pins. For a board where the

ground plane is not on the component layer, the best

technique is to connect the GND pins to the board with

a plated through-hole located close to the package.

2.4GHz SiGe,

High IP3 Low-Noise Amplifier

6

_______________________________________________________________________________________

Table 1. MAX2644 Typical Scattering Parameters

FREQ.

(MHz)

S11

MAG

S11 PHASE

(DEGREES)

S21

MAG

S21 PHASE

(DEGREES)

S12

MAG

S12 PHASE

(DEGREES)

S22

MAG

S22 PHASE

(DEGREES)

2200

0.3372

-79.36

5.1940

170.97

0.0414

157.19

0.2818

-73.71

2250

0.3098

-70.09

5.3156

166.79

0.0445

146.70

0.2204

-67.13

2300

0.3283

-57.20

5.4281

159.22

0.0469

130.62

0.1566

-50.26

2350

0.4005

-50.46

5.4175

150.70

0.0441

108.72

0.1480

-3.96

2400

0.4839

-50.28

5.3346

143.93

0.0349

85.67

0.2795

15.12

2450

0.5443

-56.33

5.0687

136.45

0.0233

58.80

0.4179

11.12

2500

0.5758

-60.09

4.9556

132.16

0.0113

27.74

0.5135

3.28

2550

0.5784

-63.61

4.5952

127.68

0.0041

-38.98

0.5622

-2.66

2600

0.5698

-66.56

4.2364

126.58

0.0063

-110.49

0.5986

-7.45

2650

0.5600

-68.51

4.1376

126.51

0.0103

-128.93

0.6208

-10.43

2700

0.5533

-69.86

4.0729

120.60

0.0133

-140.21

0.6425

-12.93

FREQ.

(MHz)

S11

MAG

S11 PHASE

(DEGREES)

S21

MAG

S21 PHASE

(DEGREES)

S12

MAG

S12 PHASE

(DEGREES)

S22

MAG

S22 PHASE

(DEGREES)

2200

0.3482

-67.06

5.2390

-177.33

0.0402

161.53

0.2873

-76.58

2250

0.3121

-58.60

5.3790

178.72

0.0435

151.97

0.2305

-69.42

2300

0.3051

-43.64

5.5982

173.43

0.0452

136.90

0.1735

-54.22

2350

0.3693

-30.34

5.8137

166.48

0.0427

116.57

0.1582

-16.42

2400

0.4769

-29.48

5.8063

158.29

0.0341

95.13

0.2687

6.52

2450

0.5619

-35.54

5.6624

150.06

0.0236

68.36

0.4043

5.00

2500

0.5948

-42.64

5.3015

142.37

0.0117

41.34

0.5030

-2.19

2550

0.5939

-47.58

4.7813

136.67

0.0034

-13.74

0.5602

-8.04

2600

0.5825

-50.94

4.3271

134.58

0.0056

-104.09

0.5952

-12.76

2650

0.5708

-53.14

4.1961

133.48

0.0096

-124.80

0.6215

-15.97

2700

0.5604

-54.35

4.1068

128.01

0.0125

-134.75

0.6434

-18.83

Table 2. MAX2644 Typical Scattering Parameters