A Compact Two-dimensional Power Divider for a Dielectric Rod Antenna Array Based on Multimode Interference

Abstract

In this work, multimode interference is investigated for the design of a two-dimensional fully dielectric power divider, well suited for the usage of dielectric waveguides. Most important, power division is achieved in a single device without the need of cascading multiple dividers. This allows to design a very compact and lightweight power divider, well applicable for dielectric rod antenna arrays. As a proof of concept for the used technique, a 16-way power divider with 4 × 4 output ports, made out of Rexolite, is realized, working in a frequency range between 90 and 105 GHz. For the S-parameter measurements, a special measurement setup, including a modular pin probe technique as well as radiation taper for waveguide termination, is proposed. The measurements are in good agreement with the simulations with a power split of − 15 dB for all output ports within the desired frequency range. This is equal to an additional insertion loss of 3 dB. To demonstrate the usability for antenna arrays, a fully dielectric rod antenna array is realized based on the proposed power divider. With this array, a gain of 22.5 dBi at 97.5 GHz was achieved.