Abstract: One way to stop electromagnetic fields from leaking outside of a module is an electric wall. Embodiments of the present disclosure are directed to emulating an electric wall with through vias. The through vias may be arranged around cavities in the printed circuit board. The density of the through vias may be selected based on an expected wavelength of the electromagnetic fields. The printed circuit board may then self-isolate components within the cavities from the electromagnetic fields.

Abstract: A resonator may include a first terminal, a second terminal, a resonator between the first terminal and the second terminal, and a reactive element in series with a switch. The reactive element in series with the switch may be connected in parallel with the resonator. The resonator may provide a first set of resonance frequencies when the switch is operated in a non-conducting state and a second set of resonance frequencies when the switch is operated in a conducting state.

Abstract: A filter device provides a wideband passband of a communication device for a RF signal. The filter device includes a first filter circuit in parallel with a second filter circuit. The first filter circuit includes a first notch filter, and has a first notch. The second filter circuit includes a second notch filter in series with a reversal circuit for phase shifting the RF signal filtered by the second notch filter, the second filter circuit having a second notch. The first and second filter circuits form a band pass filter having a passband between a lower cutoff frequency defined by the second notch and an upper cutoff frequency defined by the first notch. The band pass filter provides low insertion loss in the passband, and high insertion loss in an adjacent lower stopband below the lower cutoff frequency and in an adjacent upper stopband above the upper cutoff frequency.

Abstract: A filter device provides a wideband passband of a communication device for a RF signal. The filter device includes a first filter circuit in parallel with a second filter circuit. The first filter circuit includes a first notch filter, and has a first notch. The second filter circuit includes a second notch filter in series with a reversal circuit for phase shifting the RF signal filtered by the second notch filter, the second filter circuit having a second notch. The first and second filter circuits form a band pass filter having a passband between a lower cutoff frequency defined by the second notch and an upper cutoff frequency defined by the first notch. The band pass filter provides low insertion loss in the passband, and high insertion loss in an adjacent lower stopband below the lower cutoff frequency and in an adjacent upper stopband above the upper cutoff frequency.

Abstract: A multiplexer includes a common port, multiple filter branches and at least one switch included in a switched filter branch of the multiple filter branches. The filter branches are connected to the common port, and each filter branch corresponds to at least one predetermined frequency band and filters a radio frequency (RF) signal according to the corresponding at least one predetermined frequency band. In a first switch state of the at least one switch, the switched filter branch includes a high-Q filter having multiple high-Q components for improving roll-off of the filtered RF signal, and in a second switch state of the at least one switch, the switched filter branch includes a low-Q filter having multiple low-Q components that support a very high bandwidth for filtering the RF signal.

Abstract: A multiplexer includes a common port, multiple filter branches and at least one switch included in a switched filter branch of the multiple filter branches. The filter branches are connected to the common port, and each filter branch corresponds to at least one predetermined frequency band and filters a radio frequency (RF) signal according to the corresponding at least one predetermined frequency band. In a first switch state of the at least one switch, the switched filter branch includes a high-Q filter having multiple high-Q components for improving roll-off of the filtered RF signal, and in a second switch state of the at least one switch, the switched filter branch includes a low-Q filter having multiple low-Q components that support a very high bandwidth for filtering the RF signal.

Abstract: A matching circuit provides broadband impedance matching of first and second devices for processing RF signals in a broadband frequency range, the first device being inherently capacitive. The matching circuit includes a shunt inductor that transforms impedance of the first device to matching impedance at a matching resonance frequency in a middle portion of the broadband frequency range, and a series resonance circuit that has a series resonance frequency approximately the same as the matching resonance frequency. The series resonance circuit includes an inductor and a capacitor connected in series to the first device, and further transforms the matching impedance of the first device and the shunt inductor to a design matching impedance corresponding to the broadband frequency range. One end of the shunt inductor is connected to the first device, between the series resonance circuit and the first device or to an opposite side of the first device.

Abstract: A wide bandwidth multiplexer (MUX) is provided that performs carrier aggregation. The MUX combines at least a first LC filter that acts as a low band filter, at least a first composite filter that acts as a middle band filter, and at least one other LC or composite filter that acts as a high band filter. The wide bandwidth MUX has low insertion loss and provides sufficient attenuation at adjacent edges of adjacent pass bands to prevent overlap between adjacent pass bands.

Abstract: An acoustic filter device for telecommunication devices includes a first acoustic band pass filter having a corresponding first passband and a second acoustic band pass filter having a corresponding second passband. The second acoustic band pass filter is connected in parallel with the first acoustic band pass filter to provide a combined passband including the first and second passbands.

Abstract: A multiplexer device includes an antenna node connected to an antenna for at least one of receiving and transmitting signals; multiple band pass filters connected to the antenna node, each band pass filter having a different passband; and multiple notch filters connected in to the antenna node and the multiple band pass filters, each notch filter having a different stopband corresponding to one of the passbands of the band pass filters. The notch filters are connected in parallel with one another in order to reduce insertion loss.

Abstract: A very wide bandwidth composite band pass filter with steep roll-off of a corresponding passband includes a band pass filter and a high-Q acoustic resonator. The band pass filter has a corresponding passband with a very wide bandwidth and a passband roll-off. The high-Q acoustic filter has a corresponding stopband with a roll-off steeper than the passband roll-off, the high-Q acoustic filter being connected in parallel with the band pass filter such that a portion of the stopband is within the passband of the band pass filter, forming a combined passband. A frequency range of the combined passband is approximately the same as a frequency range of the passband of the band pass filter, and a combined roll-off of the combined passband is steeper on one side than the passband roll-off of the band pass filter.

Abstract: A multiplexer device includes at least one acoustic band pass filter connected to a common port, and a hybrid LC/acoustic filter connected to the common port in parallel with the at least one acoustic band pass filter. Each acoustic band pass filter has a corresponding passband and includes multiple acoustic resonators. The hybrid LC/acoustic filter includes at least one acoustic resonator, and has at least one capacitor replaced by a corresponding at least one acoustic resonator, respectively. Each of the at least one acoustic resonator included in the hybrid LC/acoustic filter provides a stopband response when operating in a corresponding acoustic frequency range, and acts as a capacitor when operating in a corresponding non-acoustic frequency range.

Abstract: A matching circuit provides broadband impedance matching of first and second devices for processing RF signals in a broadband frequency range, the first device being inherently capacitive. The matching circuit includes a shunt inductor that transforms impedance of the first device to matching impedance at a matching resonance frequency in a middle portion of the broadband frequency range, and a series resonance circuit that has a series resonance frequency approximately the same as the matching resonance frequency. The series resonance circuit includes an inductor and a capacitor connected in series to the first device, and further transforms the matching impedance of the first device and the shunt inductor to a design matching impedance corresponding to the broadband frequency range. One end of the shunt inductor is connected to the first device, between the series resonance circuit and the first device or to an opposite side of the first device.

Abstract: A wide bandwidth multiplexer (MUX) is provided that performs carrier aggregation. The MUX combines at least a first LC filter that acts as a low band filter, at least a first composite filter that acts as a middle band filter, and at least one other LC or composite filter that acts as a high band filter. The wide bandwidth MUX has low insertion loss and provides sufficient attenuation at adjacent edges of adjacent pass bands to prevent overlap between adjacent pass bands.

Abstract: A very wide bandwidth composite band pass filter with steep roll-off of a corresponding passband includes a band pass filter and a high-Q acoustic resonator. The band pass filter has a corresponding passband with a very wide bandwidth and a passband roll-off. The high-Q acoustic filter has a corresponding stopband with a roll-off steeper than the passband roll-off, the high-Q acoustic filter being connected in parallel with the band pass filter such that a portion of the stopband is within the passband of the band pass filter, forming a combined passband. A frequency range of the combined passband is approximately the same as a frequency range of the passband of the band pass filter, and a combined roll-off of the combined passband is steeper on one side than the passband roll-off of the band pass filter.

Abstract: A multiplexer device includes at least one acoustic band pass filter connected to a common port, and a hybrid LC/acoustic filter connected to the common port in parallel with the at least one acoustic band pass filter. Each acoustic band pass filter has a corresponding passband and includes multiple acoustic resonators. The hybrid LC/acoustic filter includes at least one acoustic resonator, and has at least one capacitor replaced by a corresponding at least one acoustic resonator, respectively. Each of the at least one acoustic resonator included in the hybrid LC/acoustic filter provides a stopband response when operating in a corresponding acoustic frequency range, and acts as a capacitor when operating in a corresponding non-acoustic frequency range.

Abstract: An acoustic filter device for telecommunication devices includes a first acoustic band pass filter having a corresponding first passband and a second acoustic band pass filter having a corresponding second passband. The second acoustic band pass filter is connected in parallel with the first acoustic band pass filter to provide a combined passband including the first and second passbands.

Abstract: A multiplexer device includes an antenna node connected to an antenna for at least one of receiving and transmitting signals; multiple band pass filters connected to the antenna node, each band pass filter having a different passband; and multiple notch filters connected in to the antenna node and the multiple band pass filters, each notch filter having a different stopband corresponding to one of the passbands of the band pass filters. The notch filters are connected in parallel with one another in order to reduce insertion loss.