Step-by-Step: Modeling Basic Yagi-Uda Arrays for Beginners

Created OnOctober 17, 2022

Updated OnJune 30, 2025

By:Tony Golden

Master Yagi-Uda simulation in AN-SOF! This quick guide walks you through modeling a 3-element array (reflector, driven element, director). Analyze radiation patterns with professional results.

Introduction to Yagi-Uda Antennas

The Yagi-Uda antenna, commonly called simply “Yagi,” is a directional antenna array developed in 1926 by Japanese researchers Hidetsugu Yagi and Shintaro Uda. This elegant design consists of three key elements:

A driven element (typically dipole)
Reflectors (usually 1-2 elements)
Directors (multiple elements)

Through careful spacing of these elements, Yagis achieve high directivity and gain in one direction while being relatively simple to construct. They revolutionized radio communication and remain popular today for applications ranging from TV reception to amateur radio.

Yagi-Uda Simulation Basics

Now that you’ve mastered cylindrical antenna basics, let’s progress to antenna arrays. This guide walks you through simulating a classic 3-element Yagi-Uda design (Fig. 1) featuring:

Director (front element)

Reflector (rear element)

Driven element (center dipole)

*Fig. 1: Yagi-Uda array geometry definition (coordinates in meters).*

Download Model

Step 1: Simulation Setup

Frequency Configuration:
- Setup tabsheet > Frequency panel
- Set: 300 MHz (UHF range ideal for Yagis)
Environment Settings:
- Environment panel > Ground Plane: Select None (standalone array)
- Excitation panel: Confirm Discrete Sources is active

Step 2: Building the Array

Element Construction:
- Draw each wire individually (as in cylindrical antenna tutorial)
- Use coordinates from Fig. 1 for precise spacing
Segment Configuration:
- Uniformly set for all elements:
  - Segments: 15 (balanced accuracy/speed)
  - Radius: 5 mm (typical for UHF)
Source Attachment:
- Right-click driven element > Source/Load/TL
- Connect voltage source to center segment
  (Pro Tip: Middle placement ensures symmetrical excitation)

Step 3: Running & Analyzing

Execute Simulation:
- Click Run Currents and Far-Field (F10)
- Observe 8.7 dBi peak gain in Results tab (Fig. 2)
Radiation Pattern:
- Click Far-Field 3D Plot to visualize:
  - Forward-directive beam (Fig. 3)
  - Characteristic side/null patterns

*Fig. 3: Yagi-Uda array gain pattern (dBi) at 300 MHz.*

Why This Matters

Teaches fundamental array principles
Demonstrates directional gain enhancement
Provides baseline for more complex designs
(Try modifying element spacing/numbers to see performance changes!)