Reconfigurable Dual-Band Bidirectional Reflection Amplifier With Applications in Van Atta Array

Abstract

We designed a reconfigurable dual-band reflection amplifier with operation frequency bands over 1.8 GHz and/or 2.4 GHz. This one-port amplifier boosts the reflected signal over either of these two frequency bands or both as a dual-band reflection amplifier. The amplifier circuit consists of an FET transistor and two p-i-n diodes, which act as switches to form a reconfigurable system. The measured reflection gains at single 1.8 GHz and 2.4 GHz frequency bands are 17.6 dB and 16.75 dB, respectively. The dual-band operation frequency shows 11.2 dB and 15 dB gain at 1.8 GHz and 2.4 GHz, respectively. Then, we realized a bidirectional amplifier using a dual-band -3 dB 90° branch line coupler integrated with two of the proposed reconfigurable reflection amplifiers. This bidirectional amplifier is a two-port bilateral amplifier. The measured reflection gains show at least 10 dB transmission gains (S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</sub> and S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sub> ) at operation frequency bands. The proposed reconfigurable bidirectional amplifier is then used in a dual-band Van Atta array. The proposed active retrodirective system outperformed passive Van Atta array by 5 dB gain with only half the number of antenna elements. Each component is investigated analytically and analyzed by advanced design system. Fabricated circuits are measured and show good agreement with simulations.