Abstract: A radar apparatus having a transmit antenna which transmits a transmit wave, a receive antenna which receives a receive wave including a reflected wave reflected on a target of the transmit wave; and an interference detection unit which judges that interference has occurred, when, of the receive waves received by the receive antenna, an average value of received power corresponding to a large distance from the radar apparatus is a threshold value or more.

Abstract: A radar apparatus having a interference detection unit which computes an average value of received power from received signals corresponding to receiving waves received by the receiving antennas, and determines that interference has occurred when the difference between this average value and the average value of the previously computed received power is a threshold value or more. Moreover, in other interference detection method, the interference detection unit determines that interference has occurred when an average value of received power corresponding to a large distance is a threshold value or more. Furthermore, in other method, the interference detection unit determines that interference has occurred when a received power value is detected as a threshold value or more when a transmission wave is not transmitted from the transmission antenna.

Abstract: A color cathode ray tube has a three in-line beam electron gun. The electron gun includes a first group of focus electrodes supplied with a first fixed focus voltage and a second group of focus electrodes supplied with a second focus voltage comprised of a fixed voltage and a dynamic voltage synchronized with beam deflection. Plural axially spaced electrostatic quadrupole lenses are formed between facing ones of the first and second groups of focus electrodes. One of the plural electrostatic quadrupole lenses nearest to the cathodes is configured so as to produce a lens action weaker on two side electron beams than on the center electron beam.