Using LNA to improve GPS sensitivity

In GPS applications, it is usually necessary to place an LNA (low noise amplifier) ​​near the antenna. This is because the GPS signal received from the GPS satellite is very weak, and it needs the LNA to amplify it. To achieve this, one-stage LNA (about 15dB) or two-stage LNA (about 27dB) can be used. Using a two-stage LNA can increase the signal amplification capability, but it also increases noise figure and power consumption.

Unlike most LNAs that use GaAs, SiGe, or SiGe BiCMOS processes, Torex ’s new two-stage LNA XC2404 uses a 0.13um CMOS process. The advantage of this process is that the product reaches 12.0mW (when fixed bias) Ultra low power consumption. The noise figure of XC2404 is only 0.z, so it is suitable for GPS applications sensitive to noise. In addition, the gain of XC2404 is as high as 26.5dB, so this product combines many advantages of low noise figure and low power consumption.

The operating voltage of XC2404 is 1.14V ～ 1.26V (1.2V typ, when fixed bias). When the system has a higher voltage such as 1.8V or 2.85V, the XC2402 can increase its flexibility by adding a resistor at the input to self-bias.

XC2404 adopts ultra-small USP-8A01 package, and both input and output can achieve 50Ω matching with a small number of external components, ensuring that it can be used in small and hand-held GPS devices.