Abstract:
Filters include first through fourth resonant cavities, an input that extends into the first resonant cavity, and an output that extends from the fourth resonant cavity. The first resonant cavity is configured to couple with the second and third resonant cavities, the second resonant cavity is configured to couple with the third and fourth resonant cavities, and the third resonant cavity is configured to couple with the fourth resonant cavity. A magnitude of the coupling between the first and third resonant cavities is configured to be substantially equal to a second magnitude of the coupling between the second and fourth resonant cavities. Combiners that include such filters are also provided.
Abstract:
A bandpass filter has a combline structure having a plurality of cascaded nodes (503, 504, 506, 508 ). A plurality of nodes in the filter are connected both to resonant elements ( 514, 517 ) (a.k.a. resonators) and non-resonant elements ( 601, 604 ) (including elements having inductances and/or capacitances that do not resonate in a predetermined frequency band of interest). The resonant frequencies of the resonant elements may be adjusted, in order to adjust the location of the center frequency and/or the width of the passband of the filter. The characteristics of the resonant and non-resonant elements are selected such that the poles of the filter, when plotted on the complex plane, move substantially along the imaginary axis when the resonant frequencies are adjusted, without substantial movement along the real axis. The resulting bandpass filter has substantially constant losses and substantially constant absolute selectivity over a relatively wide range of bandwidths.
Abstract:
The invention is a compact three-port signal combiner suitable for use in a base station having two different wireless systems. The combiner is designed as a four-port network, but one of the ports is terminated with a predetermined load, thus leaving three ports for connection to user equipment. A first port (A) receives from an antenna a first input signal comprising first and second receive bands and transmits to the antenna a first output signal comprising a transmit band. A second port (R), connected to the first wireless system, outputs to the first wireless system a second output signal comprising the first and second receive bands. A third port (T\R) outputs, to the second wireless system, a third output signal comprising the first and second receive bands and receives from the second wireless system a second input signal that is to be transmitted from the first port.
Abstract:
An in-line resonator filter has a linear array of three or more conductors. A first pair of adjacent conductors has inductive main coupling and oppositely signed capacitive main coupling, while a second pair of non-adjacent conductors has inductive cross-coupling. The first and second pairs have one conductor in common. Between the second pair of non-adjacent conductors, there is no direct ohmic connection that provides the corresponding inductive cross-coupling. The oppositely signed capacitive main coupling compensates for at least a portion of the inductive main coupling between the first pair of adjacent conductors. The in-line resonator filter is able to provide one or more transmission zeros without requiring any discrete bypass connectors that provide direct ohmic connection between pairs of non-adjacent conductors. As such, the in-line resonator filters can be smaller, less complex, and less susceptible to damage.
Abstract:
An in-line resonator filter has a linear array of three or more conductors. A first pair of adjacent conductors has inductive main coupling and oppositely signed capacitive main coupling, while a second pair of non-adjacent conductors has inductive cross-coupling. The first and second pairs have one conductor in common. Between the second pair of non-adjacent conductors, there is no direct ohmic connection that provides the corresponding inductive cross-coupling. The oppositely signed capacitive main coupling compensates for at least a portion of the inductive main coupling between the first pair of adjacent conductors. The in-line resonator filter is able to provide one or more transmission zeros without requiring any discrete bypass connectors that provide direct ohmic connection between pairs of non-adjacent conductors. As such, the in-line resonator filters can be smaller, less complex, and less susceptible to damage.
Abstract:
Provided an in-line resonator filter (400) comprising a linear array of three or more conductors (410), the linear array comprising: a first pair of adjacent conductors (410(1), 410(2)) having inductive main coupling and oppositely signed capacitive main coupling; a second pair of non-adjacent conductors (410(1) and 410(3)) having inductive cross-coupling, it is an objective of the present application to further allow the altering of the coupling within the resonator filter, and thereby tune the overall transfer function of the resonator filter to be different from the filter's inherent transfer function. The object is achieved by a first tuning element (422(3) and (4)) that extends from a bottom of the ground plane (402) of the in-line resonator filter; and a second tuning element (420) that extends from a top of the ground plane (404) of the in-line resonator filter; wherein: the first and second pairs have one conductor (410(1)) in common; and at least a portion of the oppositely signed capacitive main coupling compensates for at least a portion of the inductive main coupling between the first pair of adjacent conductors (410(1), 410(2)).
Abstract:
An in-line resonator filter (400) comprising a linear array of three or more conductors (410), the linear array comprising: a first pair of adjacent conductors (410(1), 410(2)) having inductive main coupling and oppositely signed capacitive main coupling; a second pair of non-adjacent conductors (410(1), 410(3)) having inductive cross-coupling; and one or more tuning elements (422), each extending from a ground plane of the in-line resonator filter, wherein: the first and second pairs have one conductor (410(1)) in common; between the second pair of non-adjacent conductors, there is no direct ohmic connection that provides the corresponding inductive cross-coupling; and at least a portion of the oppositely signed capacitive main coupling compensates for at least a portion of the inductive main coupling between the first pair of adjacent conductors.