Compact Transponder Research Articles

Low-Loss Transponder Aggregator Using Spatial and Planar Optical Circuit

We propose a compact transponder aggregator (TPA) consisting of a wavelength selective switch (WSS) array and a direction switch array. It has no intrinsic splitting loss and therefore the number of ports can exceed that of a conventional multicast switch. A waveguide-based frontend that incorporates spatial beam transformers enables us to increase the number of ports and integrate multiple WSSs in a simple optical system. The direction switch array is integrated in the frontend. We describe an 8 × 24 prototype, which is the largest port count yet achieved for a TPA with no intrinsic splitting loss.

Design trade‐off for a compact 5.8 GHz DSRC transponder front‐end

ABSTRACTThis letter introduces a method for the optimum design of a compact transponder front‐end for dedicated short range communication (DSRC) operating at 5.8 GHz band and suitable for electronic toll collection (ETC) vehicular applications. The DSRC transponder front‐end is based on a circularly polarized antenna and a RF diode, which provides both the functionalities of envelope detector and back‐scatterer. The design method is based on the characterization and optimization of the frequency conversion mechanism occurring in the front‐end during up and downlink while the best trade‐off between design parameters are identified on the base of sensitivity and back‐scatterer gain. These parameters optimize the DSRC transponder front‐end in the two links and thus leads to the maximum operative range. The methods are validated through the design of three prototypes responding to different design constraints and tested in the context of a realistic scenario of DSRC for ETC according to the ETSI EN300674 communication layers. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1187–1191, 2015