Patent ID: 7737904

Claim:
An antenna system for transmitting and/or receiving radio frequency signals in multiple frequency bands, the antenna system comprising: a horn antenna configured to transmit and/or receive radio frequency signals in multiple frequency bands that are spread over more than an octave bandwidth with at least a 2.44-to-1 bandwidth ratio, the horn antenna comprising: a throat disposed at a first end of the horn antenna; an aperture disposed distantly from the throat at a second end of the horn antenna; and an interior surface disposed in the horn antenna between the first end and the second end of the horn antenna, the interior surface comprising a plurality of slope discontinuities; and a feed network coupled to the horn antenna, the feed network comprising: a first waveguide section configured to provide a matching network, the first waveguide section configured to transmit and/or receive the radio frequency signals in the multiple frequency bands; a first junction configured to transmit and/or receive the radio frequency signals in first selected one or more frequency bands of the multiple frequency bands and not all of the multiple frequency bands; one or more first filters configured to pass the radio frequency signals in the first selected one or more frequency bands of the multiple frequency bands and configured to reject the radio frequency signals in frequency bands not in the first selected one or more frequency bands of the multiple frequency bands; and a first step-down waveguide section coupled to the first waveguide section, the first step-down waveguide section configured to transmit and/or receive the radio frequency signals in second selected one or more frequency bands of the multiple frequency bands and configured to reject the radio frequency signals in the first selected one or more frequency bands of the multiple frequency bands.