Design and Fabrication of an X-Band Low Noise Amplifier Using FR-4 for Military Radar and Ground Station Receiver Applications

 The low noise amplifier (LNA) plays an important role in the radiofrequency receiver front-ends, its main function is to amplify the weak receiving signal from the ground noise, as well as improving the receiver sensitivity. For LNAs which operate in the frequencies higher than the S-band, the printed circuit board (PCB) with high cost substrate materials have been used in almost designs so far, thus increasing the total price of the entire receiving unit. This paper introduces a new approach, in which a LNA has been designed using the FR-4 material, a common, low-cost substrate in PCB fabrication. The proposed LNA will maintain the quality of all of the important parameters such as gain, noise figure in compared with the LNAs designed by high cost material substrates. The stepped impedance matching technique is used in order to reach a balance between the circuit dimension and its efficiency. The frequency range of the proposed LNA lies within the X-band, which is a suitable range for military RADAR applications. Furthermore, it is possible to apply the desired LNA in the ground station receiver front-ends of a Low Earth Orbit (LEO) Earth Observation Satellite system