Abstract
Rasorbers with reconfigurable transmission frequency are of great interest over the past few years. However, existing devices exhibit a limited number of operation modes and cover a narrow transmission frequency range, making them unacceptable for wideband applications. In this work, a high-performance reconfigurable rasorber with mechanically-controlled frequency selective surface (FSS) and an electronically-tuned resistive layer is proposed. Theoretical analysis based on transmission line theory and numerical simulations is performed to investigate the performance of the proposed device. The rasorber were fabricated and free-space measurements were also carried out to validate the simulation results. The device can operate between single-, dual- and triple-passband modes by mechanically tuning the FSS under a fixed external bias voltage. Under single-passband mode, the transmission frequency can also be tuned continuously through simultaneously controlling the mechanically-tunable FSS and electronically-tunable resistive layer. A minimum insertion loss as low as 0.16 dB at 4.03 GHz is achieved from the measurement results. The maximum measured fractional absorption bandwidth is 87.9%, comparable to the state-of-art maximum absorption bandwidth of existing reconfigurable rasorber. The measured overall fractional transmission frequency range under normal incidence wave is 63.9%, far beyond that of any other existing reconfigurable counterparts.
Highlights
E LECTROMAGNETIC (EM) frequency selective rasorber is an artificial material or device that allows EM waves propagate through nearly losslessly within its transmission band while absorbs EM waves at other frequency bands
SIMULATION RESULTS OF RASORBER The reconfigurable rasorber proposed in this work is designed utilizing the frequency selective surface (FSS) and resistive layer presented above, whose unit-cell configuration is presented in Fig. 12 with an air spacer thickness of h2 = 16 mm
This paper proposes a rasorber with reconfigurable transmission frequency combining both mechanical and electronic controlling mechanisms
Summary
E LECTROMAGNETIC (EM) frequency selective rasorber is an artificial material or device that allows EM waves propagate through nearly losslessly within its transmission band while absorbs EM waves at other frequency bands. Experimental explorations of rasorbers with single absorption and transmission band were firstly reported in the early ages [2]–[7]. The device is able to operate among A-T, A-T-A and T-A modes This rasorber exhibits over 80% fractional absorption bandwidth in A-T and T-A modes, the passband of the device cannot be tuned continuously, limiting its overall transmission frequency range. In this work, a reconfigurable rasorber aiming at extending the overall transmission frequency range is proposed. It combines an electronically controlled resistive layer utilizing the equivalent tunable inductance and mechanically tuned FSS proposed in [33].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
