What characterizes a mismatched antenna system?

A mismatched antenna system is characterized by not matching the impedance of the transceiver. In radio communication, impedance matching is crucial for maximizing the transfer of power between the transmitter and the antenna. When the antenna's impedance differs significantly from that of the transceiver, it can lead to several issues.

One of the primary problems associated with a mismatched antenna is that it can result in poor performance due to reflected power. Instead of all the transmitted power being radiated effectively, some of it is reflected back to the transmitter. This can not only decrease the efficiency of the transmission but also could potentially damage the transmitter if protective measures are not in place.

Additionally, a mismatched antenna can lead to an increased Standing Wave Ratio (SWR), which indicates the degree of mismatch between the load (antenna) and the source (transceiver). A high SWR means that a significant portion of the signal is not being radiated, resulting in reduced communication effectiveness and range.

In contrast, impedance matching, optimization for multiple frequencies, or operating without losses would refer to antenna systems structured to effectively transfer power from the radio to the antenna without significant losses. Hence, these characteristics do not define a mismatched antenna system.