Based On The Research Of Transceiver Front-end Of Ads-b And Implementation

With the development of air traffic and the growing number of aircrafts, theADS-B（Automatic Dependent Surveillance-Broadcast）systerm, as a new surveillancesystem, is implemented by more and more countries worldwide to offer a great leapforward in aircraft surveillance capabilities, for ADS-B does not require expensive radarinfrastructure and the cost of implementation and maintenance is far lower. Radiofrequency (RF) T/R front-end is a critical element for ADS-B system, and itsperformance trade greatly affects the entire air traffic surveillance.In this paper, we make use of hybrid integrated circuits (HICs) technology todevelop a transceiver based on ADS-B system. The transceiver is composed oftransmitter and a receiver, and the two parts are placed in different boxes respectively.The proposed transmitter is composed of a phase-locked loop (PLL), ASK/BPSKmodulators, amplifiers and a coupler, while the proposed receiver is composed of alimiter, a low noise amplifier, band-pass filters, an amplifier and a detector. Consideringrestricted dimension and performance, a phase detector (PD) integrated with voltagecontrolled oscillator (VCO) and a programmed integer-N synthesizer is used in PLLmodule. The ASK modulation and the BPSK modulation is switched by SPDT transferswitches controlled by digital signal from FPGA. To gain an output peak power of125W, the amplifier module is designed as two stage amplifiers, one is the driveramplifier and the other is the power amplifier. In this paper, a limiter is used to protectLNA from the leakage signal of the transmitter, while band-pass filters are plased beforeand after the amplifiers in receiver to suppress harmonic and spurious signals.Finally, the module of transmitter and receiver are manufactured and tested. Theoutput frequency of PLL module is1090MHz with a low phase noise≤-90dB/Hz@10kHz, the peak power of transmitter≥51dBm. The noise figure of receivermeasured is about1.9dB, and the dynamic range≥65dB. The dimension of transmitteris130×70×30mm3, and the dimendion of receiver is52×64×21mm3.