(The) RF front-end system development for a portable multi-function X-band radar

Abstract

The radar which was initially developed for military purpose is now used more and more in our industry. It is used in many different fields such as vehicular radar, marine radar, aviation radar and weather radar. In this paper, RF front-end system which can be adopted to many different radars is studied. Frequency was selected as X-band and it was designed so that the maximum searching distance could be 1.8km when RCS (radar cross section) is $10m^2$. First of all, before designing the RF system as a block level appropriate values were calculated by radar equation. As a result, transmission power and minimum receiving power was designed to be 30dBm and -105dBm respectively and manufacturing antenna`s gain was set to be more than 25dBi. This paper developed a heterodyne X-band radar RF front-end system which uses 10 GHz and 1.8GHz local oscillator. Local oscillator affects the most to the system`s stability so it is classified as one of the key components of the transceiver module. Phase noise, frequency stability, temperature stability and output power affects the oscillator`s performance. Especially, phase noise is one of the most important parts because it decreases the SNR (signal to noise ratio) of the analogue receiver, increases the BER of transceiver for digital communication, limits channel width and it degrades the resolution of the radar system. So, many different methods are used to design a stable local oscillator for microwave communication system. In this paper, PLO (Phase Locked Oscillator) is used which generates 100MHz fundamental frequency and acquires 1.8GHz and 10GHz frequency by using Sampling Phase Detector (SPD). PLO for 1.8GHz has 8.3dBm output power and -113dBc/Hz phase noise at 10 kHz. PLO for 10 GHz has 3dBm output power and -104dBc/Hz phase noise at 10 kHz. In this paper, to follow the radar trend of having high power transmission source and developing their own radar technique along with strong countries, lightening the weigh...