Max2338 triple/dual-mode cdma lna/mixers, Applications information – Rainbow Electronics MAX2338 User Manual
Page 10
MAX2338
Triple/Dual-Mode CDMA LNA/Mixers
10
______________________________________________________________________________________
Operational Modes
The various operating modes are controlled by the logic
inputs
BAND, GAIN, LIN, and LO/2. Table 1 shows the
pin settings for the various operating modes.
Applications Information
Cascaded LNA/Mixer Performance
The LNA and mixer design optimizes cascaded perfor-
mance in all gain and linearity modes. In HGHL mode
both the LNA and mixer have a low noise figure, high
gain, and high linearity. The LNA has high gain to mini-
mize the noise contribution of the mixer, thus increasing
the receiver’s sensitivity, and the LNA has high linearity
for cross-modulation suppression. The HGLL mode is
used when the transmitter is off and cross-modulation is
not a concern. In LGHL mode, the received signal is
strong enough that linearity is the primary concern. The
LNA gain is reduced for higher system linearity.
S-Parameters
Use the S-parameters listed in the following tables to
design the RF matching circuits.
FREQUENCY (MHz)
|
S11
|
∠S11
|
S21
|
∠S21
|
S12
|
∠S12
|
S22
|
∠S22
30
0.905
-5.4
0.145
-38
0.002
-55
0.98
-47
50
0.899
-8.1
0.467
-57
0.003
-126
0.94
-72
100
0.891
-15.1
1.34
-86
0.012
-174
0.96
-117
150
0.884
-21.8
2.2
-108
0.023
176
0.96
-144
200
0.874
-28.2
2.83
-127
0.027
165.8
0.95
-162
300
0.85
-41.6
3.77
-157.5
0.029
137
0.93
-172
400
0.818
-52.5
4.24
178.3
0.030
127
0.90
155
500
0.785
-63.5
4.44
155.4
0.036
112
0.94
129
600
0.75
-71.6
4.38
140
0.040
98
0.87
100
700
0.714
-79.8
4.16
125
0.048
90
0.84
78
800
0.683
-76.5
4.03
112.6
0.059
83.0
0.793
67.5
810
0.681
-77.0
4.01
111.2
0.060
82.8
0.798
66.5
820
0.677
-77.0
3.99
110.0
0.061
82.0
0.800
65.7
830
0.675
-78.0
3.97
108.5
0.061
80.9
0.799
65.0
840
0.670
-78.3
3.96
107.2
0.062
80.6
0.792
64.2
850
0.668
-78.8
3.93
106.4
0.063
79.2
0.782
63.4
860
0.665
-79.0
3.92
104.7
0.063
78.1
0.769
62.7
870
0.661
-79.5
3.91
103.4
0.063
77.2
0.753
61.8
880
0.660
-80.0
3.89
102.1
0.063
76.5
0.733
60.6
890
0.660
-80.4
3.87
100.8
0.063
75.4
0.710
59.4
900
0.653
-81.0
3.86
99.3
0.063
73.5
0.690
57.7
1000
0.614
-97.0
3.59
86.2
0.07
20
0.680
51.8
1250
0.547
-111
3.15
60.8
0.09
-13.2
0.650
37
1500
0.457
-131
2.93
34
0.109
-36
0.610
15.9
1750
0.310
-164
2.48
18
0.14
-62
0.580
-9.6
2000
0.320
166
2.1
-40
0.185
-98
0.490
-33
2500
0.300
141
1.62
-41
0.19
-150
0.360
-70
3000
0.310
122
1.29
-66
0.19
136
0.41
-64
3500
0.360
86
1.18
-88
0.2
90
0.500
-61
4000
0.360
10
1.14
-112
0.2
43
0.480
-50
Table 2. MAX2338 Cellular Band LNA S-parameters High-Gain, High-Linearity Mode