Compact Lightweight Meander-Line Harmonic Tag for Application in Insect Tracking

This paper presents a novel single layer compact harmonic transponder tag operating at 2.9~GHz in the forward link (harmonic exciter to harmonic tag) and 5.8 GHz in the return link (harmonic tag to harmonic reader). The proposed tag consists of an asymmetric folded meander-line dipole antenna that is directly matched to the low-voltage Schottky diode at the fundamental and the second harmonic frequencies. The tag is printed on an ultrathin flexible polymide substrate and achieves a low weight of 22 mg and has a largest dimension of less than 15% of the wavelength at the fundamental frequency. The tag performance has been experimentally evaluated and compared with that of traditional wire-based dipole tags. Presented results indicate that the proposed tag provides significantly higher conversion efficiency at low incident power levels and enables a two-fold increase of the maximum detectable range.