A study of the loop as a compact antenna.

摘要

This thesis examines the suitability of the loop antenna for use as a compact radiating element. The derivation of the loop equation is reviewed, and a summary of the significant research on the electrically large loop antenna over the past century is presented. The theoretical radiation efficiency for the electrically large loop is derived. This analysis shows that the radiation efficiency of the loop antenna is drastically improved by increasing the electrical size of the loop. The theoretical input impedance is used to calculate the quality factor and bandwidth of the tuned loop antenna, and a suitable impedance matching technique is presented to attain this bandwidth. Several loop antennas were constructed, and a Wheeler cap was used to measure the radiation efficiency of these antennas. This measured radiation efficiency is shown to agree reasonably well with the theoretically predicted values.