Design Of 1090ES Mode ADS-B Signal Receiver

Automatic dependent surveillance broadcast (ADS-B) is a kind of airborne equipment. It can realize the transformation of data between aircrafts and ground stations. ADS-B system is consisting of two data model, including 1090ES and UAT. In the 1090ES pattern, the whole system mainly consists of three parts. They are RF front-end receiver, detection and decoding of the header,display of track. As the most front of receiver, RF module plays a very important role.The main tasks of RF analog receiver include the following iterms. Firstly, the modulation signal is received by 1090MHz antenna. Then we use the frequency band selection filter to select the useful signal. Because the RF signals power is small. The RF signal is amplified by the low noise amplifier. Secondely it multiplies with the local oscillation signal in the mixer. Through the intermediate frequency filter, the difference frequency of two signals is chosen. Thus the signal frequency conversion is completed. The third after the signal frequency is reduced to a lower frequency. It is easy to control the low frequency. Finally,the ASK modulation signal is demodulated into a baseband signal through a power detection and the comparator module. So, the baseband signal can be used in the back-end decoding process.This paper first discusses the technical index of the receiver. For example, sensitivity,dynamic range, noise figure and third-order cutoff point, etc. Secondly, according to project requirement,we select three different schemes. By comparison, the superheterodyne structure is selected. Then according to the structure, each module index is determined by the simulation software. The feasibility of this plan is proved. Third, each module circuit schematic diagram and PCB is designed. For example, low noise amplifer (LNA), Mixer,Filter, local oscillator (LO), demodulator and so on. At the same time, the complete circuit board is made. Finally, the circuit board debugging is performed. The results show that system work stable. And all the technical index requirements are satisfied.