Abstract: A duplexing communication signal filter has a substantially U-shaped core of dielectric material including a transmit arm, a receive arm and a base portion joining the transmit arm to the receive arm. Both the transmit arm and the receive arm each define a series of through-hole resonators. Present on the core of dielectric material is a surface-layer pattern of metallized and unmetallized areas. The pattern includes a wide area of metallization for providing off-band signal absorption, a first unmetallized area surrounding a plurality of the through-hole openings of the transmit arm, a second contiguous unmetallized area surrounding a plurality of the through-hole openings of the receiver arm, a transmitter pad metallized area on the transmit arm, a receiver pad metallized area on the receive arm, and an antenna pad metallized area.

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: The present invention is a preferred monoblock ceramic bandpass duplexer filter. The preferred filter has at least three I/O pads. One of the pads is coupled to an antenna, another is connected to a transmission circuit and the last pad is connected to a receive circuit. The filter is comprised of two sections: a transmission section and a receive section. The transmission and receive sections include resonators disposed on respective sides of the antenna pad. A first alternative signal path is disposed adjacent the ends of the transmission resonators. A second alternative signal path is disposed adjacent to the ends of the receive resonators. Each alternative signal path couples adjacent and non-adjacent resonators. A further feature of the filter of the present invention includes a shunt zero resonator for the transmission section. To the contrary, the present invention allows the elimination of a shunt zero resonator for the receive section of the filter.

Abstract: An embodiment of the invention is a modular card style radio-signal modem suitable for wireless data communication to a personal computer. The modem comprises a main circuit board substrate defining an opening, a card-to-computer connection interface operably linked to the circuit board, a radio transceiver on the circuit board in communication with the connection interface. The radio transceiver has a receiver input and a transmitter output. The card modem also includes a dielectric block antenna duplexer attached to the circuit board and suspended in the opening, the duplexer having a transmit signal input in electric communication with the transmitter output, a receive signal output in electric communication with the receiver input and an antenna connection electrode.

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 partially interdigitated combline ceramic filter is provided. The filter has a filter body with top, bottom, and side surfaces, and metallized through-holes defining quarter-wavelength resonators. The filter also has a metallization layer and at least one combline section with at least one transmission zero between the quarter-wavelength resonators. The filter also has at least one interdigital section and a coupling means between the quarter-wavelength resonators of the interdigital section. The filter also has first and second input-output pads. The partially interdigitated combline ceramic filter has the best attributes of both interdigital filter designs and combline filter designs to provide a filter which has transmission zeros, superior stopband rejection, and good harmonic performance in a small, compact, low-profile package that does not require external shielding.

Abstract: A ceramic transverse-electromagnetic-mode filter having a resistive paste base and resistive paste layer and method of tuning same is provided. The ceramic filter includes a filter body (200) comprising a block of dielectric material and having top (202), bottom (204) and four side surfaces (206, 208, 210, 212) including vertical edges (214). The filter also has metallized through-holes providing transverse-electromagnetic-mode resonators (210). At least one vertical portion in proximity to the vertical edges (214) of the block on at least one of the side surfaces is unmetallized providing a resistive paste base (218). A resistive paste layer (219) of predetermined resistivity is deposited thereon. The resistive paste layer attenuates a set of parasitic spurious responses in the filter frequency response curve while simultaneously maintaining a desired transverse-electromagnetic-mode passband.