Compact & Lightweight Antenna Designs for Harmonic Radar Application

Sammanfattning: The purpose of this paper is to design a new lightweight and compact antenna system for harmonic radar applications to be used to trace the migration of the Bogong moths. The main approach adopted in this paper to solve this problem is to build three antennas suitable for use in the real environment, where the modeling and the simulations were done in CST Microwave Studio Suite 2018. The principle applied in the system to identify and track a target is to transmit a fundamental wave signal f0 in X-band and receive its harmonic response signal at a frequency 2f0 with the help of a transponder that is fitted on the target and has non-linear characteristics. The overall link budget of the power consumption and conversion efficiency of the transponder are analyzed towards to the end. The results obtained in this research include the design of an 8×8 microstrip patch antenna array for transmission at 9.41GHz having 21 dBi of gain and measures 143.5 × 140.5 mm2; an 8×16 microstrip patch antenna array for reception at 18.82 GHz having 24 dBi of gain and measures 143.5× 76 mm2; A dual-band folded dipole design was chosen for the transponder which was approximately 30 mm in length, had a thickness of 0.005 mm and an estimated -13 dBi(21%) con- version efficiency in the ideal case. The effects of choosing different substrates for such arrays are also discussed. The impact of our obtained results provides a new solution for tracking insects which were previously deemed to be too weak due to their poor load carrying capabilities such as the Bogong moths. We have also presented a MATLAB model to estimate the conversion efficiency of a transponder for the general case.