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
