DESIGN AND IMPLEMENTATION OF MICROSTRIP ANTENNA AT 2.4 GHZ AND INTEGRATION USING RF MODULE FOR GPR (GROUND PENETRATING RADAR) APPLICATION BASED ON FMCW SIGNAL

• Main Author: LAILA - NIM : 13214042, NUR
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/29805
• Institution: Institut Teknologi Bandung

<p align="justify">In developing countries such as Indonesia, the availability of information about underground structure map is still inadequate. As a result, the construction of new buildings can damage the existing infrastructure such as power lines, data communication cables and plumbing. To prevent this, it is necessary to do land survey prior to infrastructure development. Ground Penetrating Radar (GPR) is an instrument that can be used to perform such a survey. <br /> <br /> <br /> In this final project, we develop a GPR instrument referred to as 3N-GPR, based on FMCW signal which has compact, low cost, portable, and user friendly features. 3NGPR consists of 5 main parts such as GPR frame, antenna, baseband module, signal processing module, and display. 3N-GPR is designed to detect the position of underground pipes in the depth range of 0-2 m. <br /> <br /> <br /> Specifically, the scope of work reported in this document covers the antenna and RF module. In this final project, a transmitter (Tx) and receiver (Rx) antenna, respectively, were designed and integrated with the RF module. The working frequency of the antenna is selected to be at 2.4 GHz which open a wide-range of choices to get lowcost semiconductor components available for that frequency. The type of antenna used here is a bistatic microstrip antenna where the transmitter and receiver each use two separate antennas. Microstrip antenna is chosen because it is suitable for telecommunication devices where small and light antenna dimensions and low fabrication cost is desirable. Two different types of antenna namely bow-tie antenna and circular array planar were designed, built and investigated in this work. <br /> <br /> <br /> The simulation results using CST for bow-tie antenna shows that the return loss and VSWR, are 0.64 dB and 27 respectively, at 2.4 GHz. The corresponding values for the <br /> <br /> <br /> <br /> <br /> circular array planar antenna resulting from simulations using HFSS are -15 dB and 1.3. <br /> <br /> <br /> The RF module consists of components specific for RF (Radio Frequency) which can generally be classified into 2 main parts such as transmitter and receiver. The transmitter consists of VCO (Voltage Controlled Oscillator), PA (Power Amplifier), and splitter. Whereas, the receiver consists of LNA (Low Noise Amplifier) and mixer. <br /> <br /> <br /> The circular array planar antenna was integrated with the RF module and tested on the GPR system where both antennas were facing each other. When the distance between the two antenna was varied, the resulting beat waveform also changed in both amplitude and frequency. These results demonstrated that the developed instrument already shows the proper behavior of a FMCW radar. <p align="justify"> <br /> <br />