GPS RF front-end circuit composed of MX2740

MAX2740 is a complete GPS receiver downconverter chip that completes signal processing from antenna output to digital input. The MAX2740 receiving channel includes LNA, 2-stage downconverter, variable gain amplifier and fixed gain amplifier. The chip also contains a high-performance VCO and a fixed frequency synthesizer to provide all the LO (local) oscillation frequencies required by the chip, requiring only a few external components. It is suitable for GPS/GLONASS receivers. MAX2740 has a receiving gain of more than 100dB and an AGC control range of more than 50dB. Using the superheterodyne structure of the 2-stage downconversion and the external SAW (Surface Acoustic Wave) filter, a high level of image suppression and impedance performance can be obtained.