A Tapered Metallic Baffle ${\rm TM}_{01}$ to ${\rm TE}_{11\rm Y}$ Mode Converter With ${\rm TE}_{11\rm X}$ Mode Transmission Capability

A compact TM01 to TE11Y mode converter having a linear shape and high conversion efficiency is proposed. A tapered metallic baffle at the centre and rectangular ridges on both sides of the baffle at the inner walls of waveguide are placed to achieve wide mode conversion bandwidth. The mode converter is designed and simulated for an operating frequency of 3.2 GHz. The TM01 mode is converted to TE11Y mode over the 2.95-3.24 GHz frequency band and the TE11X mode is transmitted through the waveguide over the same frequency range, both with efficiency higher than 90%. Electric field calculations show that the mode converter is capable of handling Giga-Watt level input signals. The mode conversion was verified experimentally by measuring the far-field radiation pattern at the output. The proposed mode converter has the advantage of compactness and wide bandwidth and is also useful for the case when the input to the mode converter has a TE11 mode component in addition to the TM01 mode.