Dual-Mode Phase-Conjugating/Active Van Atta Array Design Based on Dual-Band Mixer/Reflection Amplifier

In this article, a dual-mode phase-conjugating/active Van Atta array using an integrated switchless phase-conjugating mixer/reflection amplifier is presented. The proposed array consists of $N$ dual-band mixer/reflection amplifiers (DMRAs), $N$ dual-mode hybrids, and $2N$ dual-band patch antennas. The novel integrated mixer/reflection amplifier comprises a single low-noise GaAs heterojunction field-effect transistor (HJ-FET) transistor with suitable input and output matching networks and identical power supply configuration at both modes. Switchless feature, not requiring external mixers, and improved backscatter communication are the main advantages of this component for the dual-mode retrodirective array design. Furthermore, to verify the proposed mixer/reflection amplifier, a DMRA is designed and fabricated at 3.55 and 5.8 GHz resulting in an acceptable performance in both modes. Meanwhile, the phase-conjugating/active Van Atta array microstrip prototype is fabricated. It is experimentally verified using the monostatic and bistatic radiation characteristics, which clearly shows the capability of the proposed architecture as a multimode retrodirective array.