Radiation $Q$ and Gain of TM and TE Sources in Phase-Delayed Rotated Configurations

The radiation quality factor and gain of antennas are compared for two source configurations between TM/TE-only spherical mode radiation and combined TM + TE mode radiation. It is shown that the change to the combined TM + TE mode radiation can reduce the quality factor by up to 50% and increase the gain by maximum 3 dB simultaneously. The condition for maximum gain increase provides a guideline for antenna designs for successfully achieving wide bandwidths and small sizes at the same time.