March 26, 2023

This Week in Amateur Radio

North America's Premiere Amateur Radio News Magazine

Demonstrating antenna diversity, Part 1: The challenges

Antennas come in abroad range of sizes, styles, and configurations to meet frequency, bandwidth, directivity, and many other objectives; the PIGA and Yagi antennas are rather different yet widely used versions.

With a few highly specialized exceptions, all antennas in general use – ranging from tiny ones in wearables to huge broadcast-transmitter designs – are extensions, enhancements, and modifications of two basic types. These are the balanced half-wavelength dipole (also called a Hertz antenna) without ground reference, and the electrically unbalanced quarter-wavelength monopole (Marconi antenna) positioned at right angles to a ground plane (Figure 1). [Note: The term “aerial” is used in the United Kingdom and other regions of the world for “antenna” but we will stay with the US-English terminology.]

It’s important to note that there is no such thing as a general “optimum” antenna even within a given configuration, because the needs and priorities of each antenna application differ. Certainly, for most circuit and systems designs, you naturally want to minimize size, weight, and power (SWaP), and cost while maximizing other factors such as speed/performance and reliability. That all makes sense and is logical, to the extent it can be accomplished with the right tradeoffs.

Read more – EEWorld: