Abstract: A radio frequency (RF) channelizer includes a first four-port balun, a second four part balun and a pair of filters coupled between the first and second four port baluns. The filters operate such that RF signals having a frequency within a desired frequency band (so-called “in-band” signals) can propagate between the first and second baluns (e.g. from the first balun to the second balun) while signals having a frequency outside the desired frequency band (so-called “out-of-band signals”) are reflected back to the first balun. One filter reflects out-of-band signals while maintaining the magnitude and phase of the signal (i.e. with a 0 degree phase shift), while the other filter reflects out-of-band signals with a phase-reversal (i.e. with a 180 degree phase shift). With this approach, the reflected signals propagate to a sum port (or even mode port) of the first balun. In this way, the balun-filter combination results in a channelizer which separates signals into different frequency bands.

Abstract: A radio frequency (RF) channelizer includes a first four-port balun, a second four part balun and a pair of filters coupled between the first and second four port baluns. The filters operate such that RF signals having a frequency within a desired frequency band (so-called “in-band” signals) can propagate between the first and second baluns (e.g. from the first balun to the second balun) while signals having a frequency outside the desired frequency band (so-called “out-of-band signals”) are reflected back to the first balun. One filter reflects out-of-band signals while maintaining the magnitude and phase of the signal (i.e. with a 0 degree phase shift), while the other filter reflects out-of-band signals with a phase-reversal (i.e. with a 180 degree phase shift). With this approach, the reflected signals propagate to a sum port (or even mode port) of the first balun. In this way, the balun-filter combination results in a channelizer which separates signals into different frequency bands.

Abstract: A radiator element includes a pair of substrates each having a transition section and a feed surface, each of the substrates is spaced apart from one another. The radiator element further includes a balanced symmetrical feed having a pair of radio frequency (RF) feed lines disposed adjacent to and electromagnetically coupled to the feed surface of one of a corresponding one of the pair of transition sections, and the pair of radio frequency feed lines forms a signal null point adjacent the transition sections.