Abstract: Circuits and methods that provide wider bandwidth and smaller IM inductances for phase change material (PCM) based RF switch networks. The present invention recognizes that it is beneficial to consider the total high parasitic capacitance to ground of the various PCM switches in an RF switch network as constituting two or more separate capacitive contributions. This leads to several “split capacitance” concepts, including signal-path splitting, switch-block splitting, stacked-switch splitting, and splitting parasitic capacitances due to layout discontinuities, in which compensating impedance matching inductances are inserted between additive capacitances.

Abstract: Circuits and methods that provide wider bandwidth and smaller IM inductances for phase change material (PCM) based RF switch networks. The present invention recognizes that it is beneficial to consider the total high parasitic capacitance to ground of the various PCM switches in an RF switch network as constituting two or more separate capacitive contributions. This leads to several “split capacitance” concepts, including signal-path splitting, switch-block splitting, stacked-switch splitting, and splitting parasitic capacitances due to layout discontinuities, in which compensating impedance matching inductances are inserted between additive capacitances.

Abstract: Circuits and methods that provide wider bandwidth and smaller IM inductances for phase change material (PCM) based RF switch networks. The present invention recognizes that it is beneficial to consider the total high parasitic capacitance to ground of the various PCM switches in an RF switch network as constituting two or more separate capacitive contributions. This leads to several “split capacitance” concepts, including signal-path splitting, switch-block splitting, stacked-switch splitting, and splitting parasitic capacitances due to layout discontinuities, in which compensating impedance matching inductances are inserted between additive capacitances.

Abstract: There is provided an improved bandpass filter having multiple passbands, and in one embodiment, two independent passbands are provided by a single filter. Embodiments of the present invention support communication architectures with several frequency bands without requiring one signal path per band, thus realizing improvements in size, cost, and weight. One aspect of the invention utilizes strongly overcoupled resonators to achieve multiple passband response, and in various embodiments, single-ended or differential mode inputs and outputs are accommodated.

Abstract: A filter may be constructed from multiple acoustic elements in parallel. A filtering method may comprise passing a signal to be filtered through such parallel acoustic elements. Such filtering may be applicable to communication devices.

Abstract: A device includes a plurality of electrode actuated acoustic resonators coupled to form complementary paths to operate as a filter. Each acoustic resonator has an electrical input and an electrical output that contributes to a static capacitance. A compensation impedance is coupled to at least one of the paths to reduce adverse effects from the static capacitances of the acoustic resonators.

Abstract: A filter may be constructed from multiple acoustic elements in parallel. A filtering method may comprise passing a signal to be filtered through such parallel acoustic elements. Such filtering may be applicable to communication devices.

Abstract: A device includes a plurality of electrode actuated acoustic resonators coupled to form complementary paths to operate as a filter. Each acoustic resonator has an electrical input and an electrical output that contributes to a static capacitance. A compensation impedance is coupled to at least one of the paths to reduce adverse effects from the static capacitances of the acoustic resonators.

Abstract: There is provided an improved bandpass filter having multiple passbands, and in one embodiment, two independent passbands are provided by a single filter. Embodiments of the present invention support communication architectures with several frequency bands without requiring one signal path per band, thus realizing improvements in size, cost, and weight. One aspect of the invention utilizes strongly overcoupled resonators to achieve multiple passband response, and in various embodiments, single-ended or differential mode inputs and outputs are accommodated.

Abstract: One aspect of the invention provides a signal separating device comprising a first and a second circuit branch connected to an antenna port, the first circuit branch comprising a filter for passing signals in a first frequency band, and the second circuit branch comprising a filter for passing signals in a second frequency band. The first and second circuit branches being arranged so that a respective reactive impedance is presented to the antenna port in both said first and said second frequency bands. The device further comprises an impedance matching circuit at the antenna port arranged to substantially to cancel out the respective reactive impedances. In the preferred embodiment, each circuit branch presents a respective shunt capacitance to the antenna port when out-of-band and the matching circuit comprises a shunt inductor at the antenna port.

Abstract: A distributed backwards-wave balun comprising first and second pairs of coupled transmission line sections having one line section of the first coupled pair connected in series with one line section of the second coupled pair. A differential port is connected across the outer ends of the series-connected line sections and a single-ended port is connected to the inner end of the other line section of one of the coupled pairs. The balun includes an inductive load, connected in parallel with the differential port, in which the electrical length of the coupled line sections is less than one quarter of the wavelength of the centre frequency of the operating band of the balun.

Abstract: A distributed backwards-wave balun comprising first and second pairs of coupled transmission line sections 10A, 10B and 12A, 12B having one line section 10A of the first coupled pair connected in series with one line section 12A of the second coupled pair. A differential port 14 is connected across the outer ends of the series-connected line sections 10A, 12A and a single-ended port 16 is connected to the inner end of the other line section 12B of one of the coupled pairs. The balun includes an inductive load 40, connected in parallel with the differential port 14, whereby the electrical length of the coupled line sections 10A, 10B and 12A, 12B is less than one quarter of the wavelength of the centre frequency of the operating band of the balun.

Abstract: One aspect of the invention provides a signal separating device comprising a first and a second circuit branch connected to an antenna port, the first circuit branch comprising a filter for passing signals in a first frequency band, and the second circuit branch comprising a filter for passing signals in a second frequency band. The first and second circuit branches being arranged so that a respective reactive impedance is presented to the antenna port in both said first and said second frequency bands. The device further comprises an impedance matching circuit at the antenna port arranged to substantially to cancel out the respective reactive impedances. In the preferred embodiment, each circuit branch presents a respective shunt capacitance to the antenna port when out-of-band and the matching circuit comprises a shunt inductor at the antenna port.