Electrically small antennas: developments in the early decades of the 20th century

Today, it is well known that the performance of an electrically small antenna is a function of how well it is impedance matched to the transmitter and receiver and how well its radiation efficiency is maximized. Recently, much attention has also focused on optimizing the bandwidth or quality factor (Q) of small antennas as a function of their electrical size. In the dawn of radio's invention and development, a significant amount of effort was placed on optimizing the antenna's performance, particularly resonating the antenna at the desired frequency. It was well known in the first decades of the 20th century that an antenna would receive or provide more signal if properly resonated. In these early decades, radio's pioneers developed a number of antenna design techniques and approaches that are still used in today's most common antenna systems and wireless devices. In this paper, we look at some of this early pioneering work and discuss how significant and relevant it is to what antenna engineers do today. These early antenna designers laid a strong foundation for those of us that follow.