Chu´s Limit and Switched Electrically Small Antennas

This paper addresses a fundamental issue regarding electrically small antennas. It is well known that electrically small antennas suffers the fundamental limit of high Q and can not be used for broadband radiation in conventional cases. However, it is found that by integrating high-speed switch devices on the antenna, the bandwidth limit on the radiation can be overcome. This is because the high-Q value associated with electrically small antennas no longer limits the bandwidth of radiation in such a time-varying system.