Abstract: An RF signal filter includes an elongate block of dielectric material having a transmit electrode, an antenna electrode and an array of spaced resonators extending between the transmit electrode to the antenna electrode. A signal trap resonator is positioned adjacent to the transmit electrode but opposite the array of spaced resonators. The filter also includes a isolated electrode positioned between but spaced apart from the trap resonator and a local ground conductive layer. A PIN diode switch is operably connected between the isolated electrode and the local ground conductive layer for shifting of the resonant frequency of the trap resonator.

Abstract: An RF signal filter includes an elongate block of dielectric material having a transmit electrode, an antenna electrode and an array of spaced resonators extending between the transmit electrode to the antenna electrode. A signal trap resonator is positioned adjacent to the transmit electrode but opposite the array of spaced resonators. The filter also includes a isolated electrode positioned between but spaced apart from the trap resonator and a local ground conductive layer. A PIN diode switch is operably connected between the isolated electrode and the local ground conductive layer for shifting of the resonant frequency of the trap resonator.

Abstract: A ceramic filter (120) with at least one transmission zero is disclosed. The filter (120) has a filter body comprising a block of dielectric material and having top (110), bottom (112), and side surfaces, and having metallized through-holes extending from the top to the bottom surfaces defining resonators. The surfaces are substantially covered with a conductive material defining a metallized layer. The top surface (110) is uncoated. The filter (120) can also include input-output pads ( 104, 106). The bottom surface (112) has a channel (108) defining a magnetic coupling between the resonators. The channel configuration and placement can vary depending on the desired frequency response.

Abstract: A bandwidth agile, dielectrically loaded resonator filter is disclosed in which conductive strips (320, 322), plated on the top surface (302) of the filter and disposed between resonators (310, 312, 314), are selectively switched to ground in order to affect a change in the bandwidth without appreciably changing the center frequency of the filter response. PIN diode switching networks (316, 318), including a means for biasing the diode, are used to effectively ground the strips between the nearly quarter-wavelength transmission line resonators contained within the block (300) of the filter, thereby capturing a portion of the capacitive coupling (402, 404) which occurs mostly beneath the surface of the filter between adjacent resonators.