MAX2644
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
decoupling capacitors located close to the device VCC
pin. For long VCC lines, it may be necessary to add
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
(RBIAS = 750Ω, VCC = +3.0V, TA= +25°C.)
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
(RBIAS = 1.2kΩ, VCC = +3.0V, TA= +25°C.)