Nonreciprocal Yagi-Uda Filtering Antennas

TL;DR

This paper introduces a compact, nonreciprocal filtering antenna using temporal modulation, achieving high isolation and minimal gain loss, suitable for integration in communication and sensing systems.

Contribution

It presents a novel, integrated nonreciprocal filtering antenna design based on temporal modulation and microstrip resonators, demonstrating high isolation at 2.4 GHz.

Findings

Isolation greater than 20 dB achieved

Gain drop of only 3.5 dB compared to reference

Successful prototype testing at 2.4 GHz

Abstract

This paper proposes a novel and compact nonreciprocal filtering antenna based on temporal modulation. The device is composed of a third order filtering section integrated into a Yagi-Uda planar printed antenna. Strong nonreciprocity in transmission and reception is achieved at the same operation frequency by time-modulating the resonators of the filtering section. These resonators are implemented as quarter wavelength microstrip lines terminated with varactors located on the ground plane. Such plane is also employed as a reflector for the Yagi-Uda antenna and to host the coplanar waveguides that feed low-frequency signals to the varactors, thus leading to a very compact design. A prototype is manufactured and successfully tested at 2.4 GHz, showing isolation greater than 20 dB between transmission and reception modes in both E- and H- planes for all directions in space and a gain drop of only 3.5 dB compared to a reference antenna. The proposed devices can easily be integrated with other electronic circuits and may find exciting applications in communication, radar, and sensing systems.