A delay line for radio frequency circuits comprises a piezoelectric substrate, a transmission single phase unidirectional transducer (SPUDT) disposed on the piezoelectric substrate, and a receive SPUDT disposed on the piezoelectric substrate and separated from the transmission SPUDT in a direction of transmission of a main acoustic wave mode utilized by the transmission SPUDT.

Methods and apparatus, including computer program products, are provided for a tunable filter. In some example embodiments, there may be provided an apparatus. In some example embodiments, there is provided an apparatus. The apparatus may include a tunable radio frequency filter including a tunable phase shifter coupled to a resonator, wherein the tunable phase shifter tunes a center frequency of the tunable radio frequency filter by at least varying a phase of a radio frequency signal provided to the resonator. Related apparatus, systems, methods, and articles are also described.

A multi-layer piezoelectric substrate surface acoustic wave device is disclosed. The acoustic wave device can include a multi-layer piezoelectric substrate including a support substrate and a piezoelectric layer, a filter circuit including a plurality of resonators in electrical communication with the piezoelectric layer and a phase cancelling circuit integrated with the filter circuit. The piezoelectric layer has a first side facing the support substrate, a second side opposite the first side, and a sidewall extending between the first side and the second side and defining a periphery of the piezoelectric layer. The sidewall is tapered such that the first side is wider than the second side. An acoustic track of the phase cancelling circuit is offset from the plurality of resonators.

A multi-layer piezoelectric substrate surface acoustic wave device is disclosed. The acoustic wave device can include a multi-layer piezoelectric substrate including a support substrate and a piezoelectric layer, a filter circuit in electrical communication with the piezoelectric layer, and a phase cancelling circuit integrated with the filter circuit. The piezoelectric layer has a first side facing the support substrate, a second side opposite the first side, and a sidewall extending between the first side and the second side and defining a periphery of the piezoelectric layer. The sidewall is tapered such that the first side is wider than the second side. An acoustic track of the phase cancelling circuit extends between a first periphery portion and a second periphery portion of the sidewall. The phase cancelling circuit is positioned within center seventy percent of a width between the first periphery portion and the second periphery portion.

A multi-layer piezoelectric substrate surface acoustic wave device is disclosed. The acoustic wave device can include a multi-layer piezoelectric substrate including a support substrate and a piezoelectric layer, a filter circuit including a plurality of resonators in electrical communication with the piezoelectric layer, a phase cancelling circuit integrated with the filter circuit, and a pair of acoustic obstruction structures including a first acoustic obstruction structure and a second acoustic obstruction structure positioned such that the phase cancelling circuit is located between the pair of acoustic obstruction structures along an acoustic track of the phase cancelling circuit.

A multi-layer piezoelectric substrate surface acoustic wave device is disclosed. The surface acoustic wave device can include a multi-layer piezoelectric substrate including a support substrate and a piezoelectric layer, a filter circuit including a plurality of resonators in electrical communication with the piezoelectric layer, a phase cancelling circuit integrated with the filter circuit, and an acoustic obstruction structure in the acoustic track of the phase cancelling circuit. An acoustic track of the phase cancelling circuit is offset from the plurality of resonators.

A multi-layer piezoelectric substrate surface acoustic wave device is disclosed. The surface acoustic wave device can include a multi-layer piezoelectric substrate including a support substrate and a piezoelectric layer, a filter circuit including a plurality of resonators in electrical communication with the piezoelectric layer, a phase cancelling circuit integrated with the filter circuit, and an acoustic obstruction structure in the acoustic track of the phase cancelling circuit. An acoustic track of the phase cancelling circuit is offset from the plurality of resonators.

Described herein are techniques for enhancing isolation in on-chip piezoelectric-based isolators. Several techniques are described that improve isolation in piezoelectric isolators. According to an aspect of the present disclosure, a piezoelectric isolator may include structures arranged to decrease the occurrence of pockets of high electric field and/or to increase the breakdown electric field in the path from the transmitter to the receiver. Further aspects of the present disclosure relate to techniques for increasing the efficiency of piezoelectric isolators while also limiting the formation of spurious signals. The inventors have developed techniques for promoting propagation of surface acoustic waves toward the receiver while limiting propagation in the opposite direction.

Described herein are techniques for enhancing isolation in on-chip piezoelectric-based isolators. Several techniques are described that improve isolation in piezoelectric isolators. According to an aspect of the present disclosure, a piezoelectric isolator may include structures arranged to decrease the occurrence of pockets of high electric field and/or to increase the breakdown electric field in the path from the transmitter to the receiver. Further aspects of the present disclosure relate to techniques for increasing the efficiency of piezoelectric isolators while also limiting the formation of spurious signals. The inventors have developed techniques for promoting propagation of surface acoustic waves toward the receiver while limiting propagation in the opposite direction.

An acoustic wave device includes an input I-terminal and an input Q-terminal to respectively receive an I signal and a Q signal with a phase difference of about 90, an output terminal, an acoustic wave phase shift circuit connected between the input I-terminal and the output terminal, including an acoustic wave resonator, and to adjust a phase of the I signal, an acoustic wave phase shift circuit connected between the input Q-terminal and the output terminal, including an acoustic wave resonator, and to adjust a phase of the Q signal, and a phase compensator connected to at least one of between the input I-terminal and the acoustic wave phase shift circuit, between the input Q-terminal and the acoustic wave phase shift circuit, between the output terminal and the acoustic wave phase shift circuit, and between the output terminal and the acoustic wave phase shift circuit.