Design and implementation of a beat amplifier for LIPI FM-CW Radar

A beat amplifier (BA) is used to amplify a very narrowband signal originating from a mixer that takes the difference between transmitted and received signals of a frequency modulated-continuous wave (FM-CW) Radar. The frequency range of the BA is from DC up to 1 GHz. While, the input frequency for this BA is usually up to 1 MHz. If the coverage of the Radar is increased more than 100 Kms, the input frequency to the BA will be much higher than 1 MHz. The BA must be equipped by a high pass filter (before) and a low pass filter (after) in order to eleminate interference and intermodulation frequencies resulted from the mixer. The purpose of this research is to increase the knowledge and capability of the Indonesian Radar researchers in substituting imported modules for LIPI FM-CW Radar. The advantages of this research are the production cost for the local made BA will be a lot cheaper and a less dependence on overseas suppliers for the Radar modules. The design and implemented BA module achieves a satisfactory performance as shown by measurement results.