Compact Photonic-Crystals Based Isolator Using Ni–Zn Gyromagnetic Ferrite Posts

Abstract

A Faraday rotation isolator is conventionally achieved by connecting a matched load to a three-port circulator. It obtains superior performance (isolation > 20 dB) at the inevitable cost of non-ideal size. In order to adapt to the miniaturizations and integrations required for future 5G communication systems, it is particularly important to reduce the size of the devices. This work demonstrates a photonic crystal-based isolator design, comprising a unique reflecting cavity and a built-in fan-shaped coupler, where four Ni–Zn ferrite posts achieve the rotations. The design with the compact size of about 46.6 × 41.6 × 4.32 mm3 obtains excellent forward transmission efficiency and reverse isolation of 0.50 dB and 44.20 dB, respectively.

Wideband Microwave Photonic Circulator Using Two Asymmetric Partial-Height Triangle Ferrites

“…Since the photonic crystal (PhC) was first investigated [ 4 , 5 ], microwave photonic devices based on PhCs for high-frequency operations have drawn considerable concern and attracted much research [ 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. PhCs have been shown to be an effective medium for transmitting as well as controlling electromagnetic waves, which can readily facilitate the miniaturization and integration of devices at the same time [ 13 , 14 , 15 , 16 , 17 , 18 ].…”