A bulk acoustic wave resonator includes a substrate, a lower electrode connection member, a lower electrode, a piezoelectric layer, an upper electrode, an upper electrode connection member, and a dielectric layer in which the lower electrode, the piezoelectric layer, and the upper electrode are embedded. The lower electrode, the piezoelectric layer, and the upper electrode constitute a resonant portion. An extension portion extends away from either the lower electrode or the upper electrode to protrude outwardly from the resonant portion. A capacitor portion is constituted by the extension portion, a portion of the upper electrode connection member disposed above the extension portion, and a portion of the dielectric layer disposed between the extension portion and the portion of the upper electrode connection member disposed above the extension portion.

A radio-frequency transceiver circuit, comprising: a first port and a second port, configured to receive, together, a pair of differential signals; a radio-frequency matching circuit communicatively coupled to the first port and the second port, and configured to process the pair of differential signals to obtain a radio-frequency signal and configured to increase transmission power for the radio-frequency signal, wherein the radio-frequency matching circuit includes at least one capacitor, at least one distributed inductor; a band pass filter circuit, communicatively coupled to the radio-frequency matching circuit and configured to filter the radio-frequency signal, wherein the band pass filter circuit includes at least one capacitor and at least one distributed inductor; and a third port, communicatively coupled to the band pass filter circuit and configured to output the filtered radio-frequency signal, wherein both of the at least one distributed inductors have a length of microstrip line.

A radio-frequency transceiver circuit, comprising: a first port and a second port, configured to receive, together, a pair of differential signals; a radio-frequency matching circuit communicatively coupled to the first port and the second port, and configured to process the pair of differential signals to obtain a radio-frequency signal and configured to increase transmission power for the radio-frequency signal, wherein the radio-frequency matching circuit includes at least one capacitor, at least one distributed inductor; a band pass filter circuit, communicatively coupled to the radio-frequency matching circuit and configured to filter the radio-frequency signal, wherein the band pass filter circuit includes at least one capacitor and at least one distributed inductor; and a third port, communicatively coupled to the band pass filter circuit and configured to output the filtered radio-frequency signal, wherein both of the at least one distributed inductors have a length of microstrip line.

Provided are a device, a differential signal line processing method and a differential signal line processing apparatus. The device includes a first component and a second component; the first component and the second component perform signal transmission via multiple sets of differential signal lines; the device further includes at least one common-mode filter, each common-mode filter of the at least one common-mode filter being serially connected between the first component and the second component via one set of differential signal lines, and a group delay of the each common-mode filter being adopted for adjusting a delay of signal transmission on the one set of differential signal lines connected to the common-mode filter.

An apparatus includes a radio-frequency (RF) apparatus, and a multi-band matching balun coupled to the RF apparatus. The multi-band matching balun including a plurality of capacitors and a plurality of inductors. None of the plurality of capacitors and none of the plurality of inductors is variable or tunable.

Techniques are provided for a broadband microwave/millimeter-wave balanced-to-unbalanced transformer (balun). A balun implementing the techniques according to an embodiment includes a first impedance matching network configured to reduce insertion and return losses of a single-ended signal at a first port of the balun. The balun also includes a first planar bifilar coupled transmission line coupled to the first impedance matching network and configured to transform the single-ended signal into a differential signal. The balun further includes a second planar bifilar coupled transmission line coupled to the first bifilar coupled transmission line and configured to compensate for amplitude and phase imbalance induced on the differential signal by the first bifilar coupled transmission line. The balun further includes a second impedance matching network coupled to both planar bifilar coupled transmission lines and configured to reduce insertion and return losses of the differential signal at second and third ports of the balun.

A balun is enhanced with design features that extend the operational bandwidth of the balun allowing the balun to operate at lower frequencies. The design enhancements also suppress resonances that otherwise cause sudden power drops at a resonance frequency while a load is connected between the balun's differential outputs.

A transmission line transformer having a time delay network having a signal terminal and a pair of output terminals connected to the signal terminal through a corresponding one of a pair of time delay elements, the delay line elements having different time delays. A pair of transmission lines, each one having a pair of electrically coupled elements. A first one of the elements in one of the transmission lines has a first end connected to one of the pair of output terminals. A second one of the elements in such one of the transmission lines has a second end connected to a second end of one of the pair of elements in the other one of the transmission lines. The first one of the pair of elements in the other one of the pair of transmission lines is coupled to a second one of the pair of output terminals.

A transformer-based balun circuit is disclosed herein. The balun can be implemented using a spiral transformer, where primary and secondary transformer windings can be inductively coupled and can be implemented on the same metal layer (or different metal layers, e.g. vertically adjacent metal layers). The balun can further include a compensation capacitor and a digital frequency tuning circuit. The compensation capacitor can be introduced at one of the differential terminals to reduce or suppress the amplitude and phase imbalance. The digital frequency tuning circuit can be a switchable bank of capacitors, which allows for tuning the frequency of operation of the transformer-based balun.

A bulk acoustic wave resonator includes a substrate, a lower electrode connection member, a lower electrode, a piezoelectric layer, an upper electrode, an upper electrode connection member, and a dielectric layer in which the lower electrode, the piezoelectric layer, and the upper electrode are embedded. The lower electrode, the piezoelectric layer, and the upper electrode constitute a resonant portion. An extension portion extends away from either the lower electrode or the upper electrode to protrude outwardly from the resonant portion. A capacitor portion is constituted by the extension portion, a portion of the upper electrode connection member disposed above the extension portion, and a portion of the dielectric layer disposed between the extension portion and the portion of the upper electrode connection member disposed above the extension portion.