Introduction

This Getting Started guide describes how to set up and solve a two-way, low-loss waveguide combiner.

By following the steps in this guide, you will learn how to perform the following tasks in HFSS:

Draw a geometric model.
Modify a model’s design parameters.
Assign variables to a model’s design parameters.
Specify solution settings for a design.
Validate a design setup.
Run an HFSS simulation.
Create plots and a field overlay of the results (see Results of Analysis).

The Sample Problem

For this problem, the waveguide combiner is a standard WR42 model with a four-port combining junction. Each waveguide is 420 mils wide and 170 mils high. This type of waveguide combiner is used to combine the output power of two 20 GHz solid state power amplifiers (SSPA) with a very compact size and low insertion loss.

The outputs of the SSPAs are fed into Ports 2 and 4 of the waveguide with a 90-degree out-of-phase separation to steer the output power of the amplifiers to port 1. Port 3 of the waveguide is the isolated port where the impedance mismatch at the output (port 1) is absorbed.

This problem is also described and analyzed in the following reference:

Arcioni, Paolo, Perregrini, Luca, Bonecchi, Fulvio, “Low-Loss Waveguide Combiners for Multidevice Power Amplifiers,” The Second International Conference on Electromagnetics in Aerospace Applications, September 1991.

The geometry for this waveguide combiner problem is shown below:

View of the waveguide combiner with the ports and combining junction highlighted

Results of Analysis

After setting up the waveguide combiner model and generating a solution, you will:

Create Modal S-parameter reports (2D x-y plot).
Create a field overlay of the E-field magnitude.
Create an animation of the E-field magnitude overlay.