For LNA with gain step in MMDS band (2.65GHz)

For LNA with gain step in MMDS band (2.65GHz)

Abstract: MAX2645 is a SiGe low noise amplifier (LNA) with 25dB, shutdown mode, and adjustable IP3 function. LNA is optimized for wireless broadband applications in the 2.65GHz MMDS band. In high gain mode, the MAX2645 has a gain of + 17.5dB, a noise figure of 2.0dB, and an IIP3 of + 3.7dBm. Insertion loss of 7.9dB and IIP3 of + 15.8dBm in low gain mode. The typical operating voltage is + 3.3V, the current is 8.9mA in high gain mode, and 2.7mA in low gain mode, and the typical current is 0.1µA in shutdown mode.

Table 1 summarizes the performance of MAX2645 operating at 2.65GHz. Figure 1 shows the principle diagram for optimizing the performance of MAX2645 at 2.65GHz. Table 2 is the device list. Figures 2 to 6 show the performance of the LNA in high-gain mode and low-gain mode from 2.6GHz to 2.7GHz. The tuning capacitor is the general Murata 0402 GRP1555C (GRM36) series, and the tuning inductor is the Murata 0402 chip inductor LQP10A series. For more information, please consult the MAX2645 SiGe LNA data sheet and evaluation board manual.

Table 1. MAX2645 SiGe LNA performance at 2.65GHz

Mode ICC (mA) Gain (dB) NF (dB) IIP3 (dBm) S11 (dB) S22 (dB)
High Gain 8.9 +17.5 2.0 +3.7 10.5 19.4
Low Gain 2.7 -7.9 14.2 +15.8 8.4 8.2

Note: VCC = + 3.3V, RBIAS = 20kΩ

Figure 1. Schematic diagram of the MAX2645 SiGe LNA circuit operating at 2.65GHz
Figure 1. Schematic diagram of the MAX2645 SiGe LNA circuit operating at 2.65GHz

Table 2. Device List
DesignaTIon QuanTIty DescripTIon
C1 1 2.0pF ± 5% ceramic capacitor (0402) Murata GRM36C0G020C50
C2 1 47pF ± 5% ceramic capacitor (0402) Murata GRM36C0G470J50
C3 1 10µF, 16V tantalum capacitor AVX TAJC106K016
C4, C5 2 0.1µF ± 10% ceramic capacitors (0603) Murata GRM39X7R104K016
C6 1 33pF ± 5% ceramic capacitor (0402) Murata GRM36C0G330J50
C7 1 10pF ± 5% ceramic capacitor (0402) Murata GRM36C0G100D50
L1 1 3nH ± 5% inductor (0402) Murata LQG15HN3N0S02
L2 1 6.8nH ± 5% inductor (0402) Murata LQG15HN6N8J02
L3 1 5.6nH ± 5% inductor (0402) Murata LQG15HN5N6S02
R1 1 20kΩ ± 1% resistor (0603)

Figure 2. MAX2645 gain frequency characteristic diagram
Figure 2. MAX2645 gain frequency characteristic diagram

Figure 3. MAX2645 noise figure frequency characteristics
Figure 3. MAX2645 noise figure frequency characteristics

Figure 4. MAX2645 input IP3 frequency characteristic diagram
Figure 4. MAX2645 input IP3 frequency characteristic diagram

Figure 5. MAX2645 input return loss frequency characteristic graph
Figure 5. MAX2645 input return loss frequency characteristic graph

Figure 6. MAX2645 output return loss frequency characteristics
Figure 6. MAX2645 output return loss frequency characteristics

Shareconn development Co.,Ltd can offer series DC power cables. We often produce 5.5*2.1 DC cables,5.5*2.5 DC cables,3.5*1.35 DC cables and so on.


We are specialized in producing national standard PVC wires, power cords, cord sets, cable reels, sockets and lights-Our main products, AC and DC connector series, can be widely used in PC computers, electronic products, electric appliance, power tools, etc.

Power Cable Assemblies

Power Cable Assemblies,Power Extension Cable Assembly,Electrical Custom Power Cable Assembly, Electronic Assemblies

Shareconn Development CO.,LTD , http://www.share-conn.com