Abstract: An ultrasonic detector suitable for mounting in a position for surveying an area for a source of airborne ultrasound, which detector comprises a sensor for detecting an ultrasonic sound signal, characterized by a transducer configured to produce a broadband ultrasonic sound signal for reception by said sensor enabling said ultrasonic detector to perform a self-test.

Abstract: Systems, methods, and apparatus for a disk resonator gyroscope are disclosed. In one or more embodiments, the disclosed method involves sensing, by at least one first axis sensor/driver electrode associated with a first axis of a resonator, motion associated with the resonator. The method further involves driving at least one first axis sensor/driver electrode with a first axis actuation signal produced by first axis drive circuitry associated with the first axis of the resonator. Also, the method involves sensing, by at least one second axis sensor/driver electrode associated with a second axis of the resonator, the motion associated with the resonator. Further, the method involves driving at least one second axis sensor/driver electrode with a second axis actuation signal produced by second axis drive circuitry associated with the second axis of the resonator.

Abstract: According to embodiments of the present invention, an energy harvesting device is provided. The energy harvesting device includes a plurality of energy harvesting elements, each energy harvesting element including a transducer, and at least one spring arranged in between at least two energy harvesting elements of the plurality of energy harvesting elements to mechanically couple the at least two energy harvesting elements to each other. According to further embodiments of the present invention, a method for forming an energy harvesting device is also provided.

Abstract: A vector sensor for use in acoustic instruments is described. The vector sensor includes: a cylindrical bulkhead partition defining a plurality of channels extending longitudinally on a circumferential wall of the bulkhead partition between a first surface and a second surface of the bulkhead partition; first and second cylindrical piezoelectric transducing pieces affixed to the bulkhead partition and extending outwardly as cantilever beams and contained within respective pressure housing capsules. The sensor may include cylindrical foam end pieces fitted over the capsules and having corresponding channels in their outer surfaces that correspond to channels in the bulkhead partition, so as to allow wiring and strength members to pass through. The cylindrical piezoelectric transducing pieces may be formed from a piezoelectric cylindrical tube with a first electrode covering its inner surface and a second electrode on its outer surface.

Abstract: A detector of an event includes an electrical energy generator formed by a flexible piezoelectric element with a weight fastened to the flexible piezoelectric element that is biased with the weight in a position with the piezoelectric element flexed. In response to detection of the event, a trigger releases the weight so as to cause a vibration of the piezoelectric element. This vibration is converted by the flexible piezoelectric element into electrical energy. An electronic system is power by the electrical energy and is operable to generate an electrical signal indicative of the detected event.

Abstract: A piezoelectric sensor comprises a support structure, a channel extending through the support structure, a sensing material stack coupled to the support structure and extending over the channel, and a filler material disposed within the channel and over the sensing material stack. The sensing material stack comprises an structural layer, a first electrode layer disposed on the structural layer, a piezoelectric material disposed in a piezoelectric layer on the first electrode, and a second electrode disposed on the piezoelectric layer opposite the first electrode layer.

Abstract: A resonant inductive sensing system includes a sensor resonator and an inductance-to-data converter (IDC) including an algorithmic control loop with operational and calibration phases. The resonator is characterized by a resonance state corresponding to a sensed condition. The IDC includes a negative impedance stage and a loop control stage. During the operation phase, the negative impedance stage drives the resonator with a selected (controlled) negative impedance. The loop control stage includes detection circuitry that detects resonance state, and range comparison circuitry that generates an out-of-range signal when the detected resonance state is not within a pre-defined range of resonance states.

Abstract: A pressure detector includes: a case provided with a hole portion; support pillar members standing on the bottom surface of the case and each including a tapered portion at an end of each of the support pillar members; a circuit board including a sensor having a detection aperture, and mounting holes into which the respective tapered portions are insertable; and a packing provided with a through hole. The case and the circuit board are fixed by a cured resin while the hole portion is connected to the detection aperture via the through hole by inserting the tapered portion of each of the support pillar members into the mounting hole of the circuit board and by sandwiching the packing between the bottom surface of the case and the sensor.

Abstract: There is provided a piezoelectric vibration actuator including: a flat cover member; a vibration portion including a vibration plate that is spaced apart from the cover member in parallel by a predetermined distance and a piezoelectric element that generates a vibration force by repeatedly expanding and contracting according to power applied from the outside; a weight portion disposed on the vibration portion to increase the vibration force of the piezoelectric element; and a binding member fixing the vibration portion and the weight portion. In addition, an enclosure portion is interposed between the weight portion and the vibration portion to enclose the center areas of the vibration portion, thereby making it possible to protect the piezoelectric element.

Abstract: A combustion pressure sensor is formed of a ring-shaped cylindrical body. The combustion pressure sensor detects combustion pressure in a combustion chamber of an engine by being attached to an outer periphery of a tip of a functional component attached to the combustion chamber. The cylindrical body forms sealed space sealed with a ring-shaped diaphragm on one side and with a ring-shaped support member on an opposite side. The sealed space is defined by an external cylindrical member and an internal cylindrical member coaxial with each other. The diaphragm has a ring-shaped pressure receiving part formed on a side near the combustion chamber to receive pressure from outside and a ring-shaped transmitting part formed on a rear surface of the diaphragm. A pressure transmitting member and a pressure detecting element are provided in the sealed space.

Abstract: The invention relates to a method for producing an acceleration sensor having a housing (1), which has a cylindrical or cubic basic shape, having at least one internal support (4) and having a sensor element (2) arranged thereon. According to the invention a sensor element (2) comprising a main body (29) having a head part (21) and an end face (24) opposing said head part (21) is premounted, by surrounding the head part (21) with at least one piezoelectric measuring element (23), a seismic composition (22) and a clamping ring (27). The end face (24) is subsequently positioned on the inner support (4) of the housing (1) in contact therewith to form a contact zone (7) between the end face (24) and the support (4). Finally, the sensor element (2) is welded in this contact zone (7) to the housing (1). The invention further relates to an acceleration sensor produced using said method.

Abstract: A method and geophysical acceleration sensor (100) for measuring seismic data and also for protecting the sensor from shock. The sensor includes a housing (102); a flexible beam (104) having a first end fixedly attached to the housing; a piezoelectric layer (108) attached to the flexible beam; a seismic mass (112) attached to the flexible beam; and a first movement limiter (130) connected to the housing and configured to limit a movement of the flexible beam. A distance between a tip of the first movement limiter and the flexible beam is adjustable.

Abstract: A power generator including: a vibration system configured to be attached to a vibrating member; and a power generating element attached to the vibration system. The vibration system is a multiple-degree-of-freedom vibration system that includes a first vibration system having a first mass member elastically supported by a first spring member, and a second vibration system having a second mass member elastically connected to the first mass member by a second spring member. The power generating element is arranged between the first and second mass members, and vibration applied from the vibrating member causes relative displacement of the first and second mass members so that vibration energy of the vibrating member is input to the power generating element. A natural frequency of the first vibration system is different from that of the second vibration system.

Abstract: A vibration power generator includes a vibration system attached to a vibrating member. The vibration system includes a first vibration subsystem, and a second vibration subsystem attached to the first vibration subsystem. The first vibration subsystem includes an elastic member attached to the vibrating member, and a first mass member attached to the elastic member. The second vibration subsystem includes a plate spring integral with a piezoelectric element, and a second mass member attached to the plate spring. The first vibration subsystem has a resonant frequency that is substantially equal to a resonant frequency of the second vibration subsystem.

Abstract: The present invention relates to an energy harvester device comprising an elongate resonator beam comprising a piezoelectric material, the resonator beam extending between first and second ends; a base connected to the resonator beam at the first end with the second end being freely extending from the base as a cantilever; a mass attached to the second end of the resonator beam; a package surrounding at least a portion of the second end of the resonator beam; and a compliant stopper connected to the package, where the stopper is configured to stabilize motion of the cantilever to prevent breakage. Also disclosed is a system, a method of powering an electrically powered apparatus, and methods of producing an energy harvester device.

Abstract: There is provided is a stereo headphone provided with a pair of earphones having a cartilage conduction unit, a sheath unit connected to the cartilage conduction unit, and a piezoelectric bimorph of a vibration source connected to the cartilage conduction unit covered by the sheath unit without making contact with the inner wall thereof. The cartilage conduction unit is an elastic body. The cartilage conduction unit is in contact with the entrance to the external auditory meatus and has a passage hole in communication with the external auditory meatus. The vibration source is supported by a thick portion on the tragus side at the periphery of the passage hole. In accordance with a more specific feature, the thick portion is provided. The outer shape of the sheath has a thickness in the direction of the earhole that is less than the thickness in the direction orthogonal thereto.

Abstract: A yaw-rate sensor, having a substrate which has a main extension plane, for detecting a yaw rate about a first direction extending either parallel to the main extension plane or perpendicular to the main extension plane. The yaw-rate sensor has a drive device, a first Coriolis mass and a second Coriolis mass, the drive device being configured to drive at least one part of the first Coriolis mass and at least one part of the second Coriolis mass in a direction parallel to a drive direction extending perpendicular to the first direction.

Abstract: A micromechanical acceleration sensor is provided, including a substrate, a first seismic mass, which is movably suspended on the substrate and deflectable in an acceleration acting on the substrate in a first direction, first detection means for detecting a deflection of the first seismic mass in an acceleration acting on the substrate in the first direction, a second seismic mass, which is movably suspended on the substrate and deflectable in an acceleration acting on the substrate in a second direction, the second direction running perpendicularly to the first direction, second detection means for detecting a deflection of the second seismic mass in an acceleration acting on the substrate in the second direction, the second seismic mass furthermore being deflectable in an acceleration acting on the substrate in a third direction, the third direction running perpendicularly to the first direction and to the second direction, and third detection means for detecting a deflection of the second seismic mass

Abstract: An electrical connector assembly for the electrical connection of one or more minerally insulated cables (11), the assembly comprising a pot seal arrangement (10) arranged in use to connect the minerally insulated cable (11) to a connector (22); at least one cable alignment plate (21, 31); and, a backshell (20) shaped so as to contain the pot seal (10) and cable alignment plate (21); the cable alignment plate (21) and pot seal (10) being arranged so as to locate within the backshell (20) such that in use, connecting the backshell (20) to the connector (22) forces the backshell (20), cable alignment plate (21) and pot seal (10) into a cooperative engagement.

Abstract: Disclosed is an ear microphone which includes: a microphone for converting a voice signal provided from the external auditory meatus of a user to an electric signal; a speaker for converting the electric signal provided from an external device to the voice signal; and a soundproof member having a microphone receiving groove for fixing and supporting the microphone to the inside of the housing and a speaker receiving groove for fixing and supporting the speaker to the inside of the housing.

Abstract: An auxiliary device including an energy harvester and an electronic device including the auxiliary device are provided. The auxiliary device includes: a housing; a storage module which is moveable within the housing; and at least one piezoelectric transducer which disposed in the housing, such that a motion of the storage module causes a deformation of the piezoelectric transducer, thus generating electric energy. An end of the piezoelectric transducer may be fixedly connected to the storage module.

Abstract: A dual output accelerometer having first and second output channels, comprises a supporting base, a first transducer comprising a plurality of inter-connected first piezoelectric elements, a second transducer comprising a plurality of inter-connected second piezoelectric elements and a seismic mass. Each of the first piezoelectric elements and the second piezoelectric elements are interleaved with one another, and are co-located with the seismic mass, the co-located first and second piezoelectric elements and the seismic mass being fastened to the supporting base by a rigid mechanical coupling. The interleaved first and second piezoelectric elements provide an improved first output channel to second output channel matching.

Abstract: A display device includes an accommodating member in which an inner space is defined, a display panel accommodated in the inner space in the accommodating member, and an energy generating module disposed between the accommodating member and the display panel and which produces a triboelectricity, where the energy generating module includes a first electrified substrate fixed to the accommodating member and a second electrified substrate disposed on the first electrified substrate, the second electrified substrate moves relative to the first electrified substrate by a frictional event, and the triboelectricity is produced by the relative movement between the first and second electrified substrates.

Abstract: Provided is a micro electro mechanical system (MEMS) resonating accelerometer. The MEMS resonating accelerometer according to the present invention comprises: a first inertial mass; a second inertial mass which is spaced at a predetermined distance from the first inertial mass on a first axis; an elastic body which is provided between the first and second inertial masses so as to apply elasticity; and a tuning fork which is connected to the elastic body and measures the change of frequency according to acceleration, wherein the longitudinal direction of the tuning fork is parallel to a second axis which is perpendicular to the first axis, the elastic body has an opening portion being in a circular shape with a portion thereof removed, and one end of the tuning fork penetrates the opening portion and is connected to the inner surface of the elastic body.

Abstract: An accelerometer. At least some of the example embodiments include an accelerometer having a first piezoelectric element having a first polarization, the first piezoelectric element defining an upper surface and a second piezoelectric element having a second polarization, the second piezoelectric element defines a lower surface parallel to the upper surface of the first piezoelectric element; the first polarization being aligned with the second polarization. The accelerometer further includes a first mounting plate that defines a first aperture, the first and second piezoelectric elements extending through the first aperture such that the first mounting plate transects the first and second piezoelectric elements. The piezoelectric elements define a first cantilever portion on a first side of the first mounting plate, and the piezoelectric elements define a second cantilever portion on a second side of the first mounting plate opposite the first side.

Abstract: A vibration generating apparatus may include a housing having an internal space, an elastic member mounted in the internal space, a piezoelectric element having one surface thereof mounted on the elastic member, and a mass body fixed to the other surface of the piezoelectric element by a buffering adhesive.

Abstract: An apparatus for driving and sensing motion in a gyroscope including a dielectric mass, an anchor, a spring coupled between the anchor and the dielectric mass, a substrate adjacent the dielectric mass, an insulator layer on the substrate, and a first electrode and a second electrode on the insulator layer. When an alternating current voltage is applied between the first and second electrodes, an electric field gradient is generated in the dielectric mass and causes the dielectric mass to move relative to the anchor. When the dielectric mass has motion relative to the anchor and a voltage is applied between the first and second electrodes, the movement of the dielectric mass generates a current at the first and second electrodes proportional to the motion.

Abstract: A low density accelerometer includes a buoyant outer layer and a rigid hollow housing within the outer layer. The housing includes an upper member and a lower member and is configured to form a groove at the junction of the upper and lower member. A disk shaped sensing element configured in a ring defining an aperture is configured to engage the groove along an outer edge of the annular ring. A solid proof mass is configured to fit in the center of the annular ring and configured with a threaded bore on an upper surface of the proof mass. The mass is secured to the sensing element by a retainer such as a Belleville washer in contact with the upper surface of the sensing element circumferentially about the aperture and a threaded fastener passing through the retainer and the aperture in the sensing element, and threadingly engaging the threaded bore in the proof mass.

Abstract: A measuring element formed of a piezoelectric crystal of symmetry class 32 for measuring a force Fz, which acts perpendicularly on the plane x-y and causes a charge accumulation on surfaces of the plane x-y. Applications are measurements in which the transverse forces Fxy orthogonal to the force Fz, which generate an error signal at the measuring element, are expected on the measuring body. The measuring element includes at least four identical measuring element segments having straight edges. In the x-y plane the segments are arranged side by side and spaced apart by narrow gaps at the edges. Together, the segments form the shape of a disc or perforated disc for reducing the interference signals caused by the transverse forces Fxy on the measuring element. The crystal orientations in the x-y plane of all segments are oriented in the same direction or orthogonal to each other.

Abstract: A method for providing electrical energy to a self-destruct fuze for submunitions contained in a projectile. The method including: using a firing acceleration of the projectile to deform at least one elastic element to store mechanical energy in the elastic element; converting the stored mechanical energy to electrical energy; and providing the electrical energy at least indirectly to the self destruct fuze for detonation of the self destruct fuze.

Abstract: A method and apparatus for detecting underwater sounds is disclosed. An embodiment of the apparatus includes a substrate with a vacuum-sealed cavity. A support structure and an acoustic pressure sensor are situated on the substrate. The support structure of the apparatus may include a first oxide layer situated on the substrate, a silicon layer situated on the first oxide layer, and a second oxide layer situated on the silicon layer. The acoustic pressure sensor of the apparatus includes a first electrode layer situated on the substrate, a piezoelectric layer situated on the first electrode layer, and a second electrode layer situated on the piezoelectric layer. In one embodiment, the surface area of the second electrode layer is between about 70 to 90 percent of the surface area of the piezoelectric layer. In various embodiments, the support structure is thicker than the piezoelectric layer.

Abstract: A sensor assembly includes a frame defining a sensor axis having opposing endplates with axially extending supports, wherein the opposing endplates are connected by a pair of axially extending side beams. A suspended mass is within an interior of the frame suspended from the supports of the frame. A plurality of spacers are operatively connected to the endplates and supports of the frame. A plurality of piezoelectric material layers are operatively connected to sides of respective spacers opposite the frame to damp vibrations.

Abstract: There are provided a piezoelectric vibration module and a vibration generating apparatus including the same. The piezoelectric vibration module includes: a piezoelectric actuator including a piezoelectric element deformed in both a first direction and a second direction perpendicular to the first direction through the application of electrical power thereto; at least one first rod transferring deformation force of the piezoelectric actuator in the first direction; at least one second rod converting deformation force of the piezoelectric actuator in the second direction into deformation force in the first direction and transferring the converted deformation force; and a mass body connected to the first and second rods and disposed on the piezoelectric actuator so that displacement is generated in the first direction.

Abstract: A solid state ignition safety device for rocket assisted projectiles having a piezoelectric generator that charges a capacitor during the initial acceleration of the projectile by the launching propellant charge. The capacitor is then discharged after a delay to ignite an initiator, which ignites the rocket motor of the projectile. A time delay circuit can be integrated into the ignition safety device to further delay the ignition of the initiator until the projectile has reached the ideal point in its trajectory to ignite the rocket motor.

Abstract: A pressure sensor including a lower substrate having two electrodes partially covered with a semiconductor layer and a piezoelectric layer made of a piezoelectric material, and in contact with the semiconductor layer in such a way that semiconductor material is in contact with the piezoelectric material and with the two electrodes, deposited thereon. The electrodes are intended to be connected to a voltage source or to a device for measuring the intensity of a current generated by the displacement of the electric charges in the semiconductor layer between the electrodes, said electric charges being created when a pressure is exerted on the piezoelectric layer.

Abstract: There is disclosed a dual output compressive mode accelerometer having first and second output channels, comprising: a supporting base; first and second transducers mounted on the supporting base adjacent to one another, each transducer comprising a piezoelectric element and a seismic mass, the piezoelectric element positioned between the supporting base and the seismic mass; and a rigid mechanical coupling between the first and second transducers, the rigid mechanical coupling coupled to both of the first and second transducers above the supporting base.

Abstract: The invention relates to a temperature compensated micromechanical resonator and method of manufacturing thereof. The resonator comprises a resonator element comprising a semiconductor crystal structure, which is doped so as to reduce its temperature coefficient of frequency, transducer means for exciting to the resonator element a vibrational mode. According to the invention the crystal orientation and shape of the resonator element are chosen to allow for a shear mode having a saddle point to be excited to the resonator element, and said transducer means are adapted to excite said shear mode to the resonator element. Accurate micromechanical resonators with now temperature drift can be achieved by means of the invention.

Abstract: In a method for manufacturing at least one mechanical-electrical energy conversion system including multiple individual parts, and a mechanical-electrical energy conversion, multiple different individual parts are positioned in an assembly device and joined in joining areas assigned to the individual parts in the assembly device, the individual parts including at least one piezoelectric element, one support structure and one seismic mass.

Abstract: Provided are an energy harvester using a mass, and a mobile device including the energy harvester. The energy harvester includes: a mass; first and second substrates spaced apart from each other, wherein one of the first and second substrates is connected to the mass; first and second electrodes provided on the first and second substrates; and an energy generator provided between the first and second electrodes, wherein the energy generator generates electric energy upon a relative movement between the first substrate and the second substrate caused by a movement of the mass.

Abstract: An inertial drive actuator includes a displacement unit which generates a minute displacement in a first direction, and in a second direction, a coil which generates a magnetic flux, a movable object which has a surface facing at least one surface of the coil, and a first yoke which converges the magnetic flux generated by the coil, at a predetermined position, a detecting unit which detects an electric signal of the coil, reflecting a change in the magnetic flux near the coil based on a positional relationship of the movable object and the coil, and a judging unit which judges a position of the movable object, and the inertial drive actuator drives the movable object by controlling a frictional force acting on the movable object, by controlling the magnetic flux generated by the coil, and the coil carries out generation of the magnetic flux and detection of the magnetic flux.

Abstract: The invention relates to an electricity generator having recovery of mechanical vibration energy, including a bistable system suitable for adopting one stable position or another relative to two ends in response to being energized in a predetermined direction (FEXT); at least one monostable oscillating system suitable for periodically engaging with at least one of the two ends, in response to said energizing; and a device for converting the movement of the element of the bistable system into electric power.

Abstract: There is provided a vibration actuator including: a housing providing an internal space and including holes formed to allow the internal space to be in communication with the outside; a diaphragm disposed to separate the internal space into first and second chambers; a mass body coupled to the diaphragm; and a piezoelectric element coupled to one inner surface of the housing and disposed under the mass body.

Abstract: Disclosed are a vibration generator, which can increase the vibration force of a vibration plate by additionally applying the mass of a mass body to the vibration plate, and an electronic device including the same. The vibration generator includes at least one piezoelectric element mounted inside the case and subjected to compression and expansion in response to input power, a vibration plate including a body elongated in a preset lengthwise direction and having the at least one piezoelectric element mounted thereon, and generating vibrations by the compression and expansion of the at least one piezoelectric element, and at least one mass part adding a preset magnitude of mass to the vibration plate.

Abstract: Systems and methods for providing haptic feedback at multiple resonance frequencies are disclosed. For example, one disclosed apparatus includes a resonator with a base and a plurality of projections, a first projection of the plurality of projections having a first resonance frequency and a second projection of the plurality of projections having a second resonance frequency, and a piezoelectric actuator coupled to the resonator and operable to output a haptic feedback effect at the first resonance frequency and at the second resonance frequency.

Abstract: There are provided a piezoelectric vibration module and a vibration generating apparatus including the same. The piezoelectric vibration module includes: a piezoelectric actuator including a piezoelectric element deformed in both a first direction and a second direction perpendicular to the first direction through the application of electrical power thereto; at least one first rod transferring deformation force of the piezoelectric actuator in the first direction; at least one second rod converting deformation force of the piezoelectric actuator in the second direction into deformation force in the first direction and transferring the converted deformation force; and a mass body connected to the first and second rods and disposed on the piezoelectric actuator so that displacement is generated in the first direction.

Abstract: There is provided a vibration generating apparatus including: a housing having an internal space; an elastic member having an edge part fixedly attached to the housing; a piezoelectric element fixedly attached to a lower surface of a central portion of the elastic member; and a mass body fixedly attached to an upper surface of the central portion of the elastic member.

Abstract: The invention embodies a harvester (12) to convert energy from mechanical domain to electrical domain. The harvester comprises at least one inertial body (6), at least one beam (7, 9), a support (8) to said at least one beam (7, 9) and transducer means (10, 16), wherein said at least one beam (7, 9) configures the inertial body (6) into a pendulum structure being suspended from said support (8) so that the beam (7, 9) is allowed to bend according to the kinetic state changes of the inertial body (6), and is configured to interact with at least one transducer means (10) that is/are configured to produce change in the electrical state of said transducer means (10, 16) responsively to the kinetic state of the beam (7, 9). The invention also shows harvester module, matrix and a harvester system comprising at least one embodied harvester. The invention also shows a tire and a foot wear that comprises at least one harvester embodied.

Abstract: A force generator for mounting on a structure in order to introduce vibrational forces in a controlled manner into said structure for affecting vibrations is provided. The force generator includes at least one spring arm on which a flexural arm having an inertial mass and extending in the direction toward the attaching point is fastened, and having at least one piezo transducer at both ends of the spring arm. The center of gravity of the inertial mass is disposed in the region of the center of the spring arm. Alternatively, two guide springs are disposed on both sides of the spring arm parallel thereto, in order to generate a vibrational motion, wherein the fastening point of the flexural arm comprises an unchanged orientation during the vibrational motion.

Abstract: A piezoelectric device system has a first piezoelectric element, a proof mass, a second piezoelectric element, and a microstructure output portion. The first piezoelectric element is oscillated by a power source. The proof mass is disposed between the first piezoelectric element and the second piezoelectric element, and transmits the vibration from the first piezoelectric element to the second piezoelectric element so as to make the second piezoelectric element move and generate power. The microstructure output portion is disposed on the other side of the second piezoelectric element opposite to the proof mass for transmitting the power generated by the second piezoelectric element.

Abstract: Time-aligned handover for a mobile device is described herein. The time-aligned handover is achieved by determining a time difference between serving and target cells and determining a target propagation delay based on the time difference. In some cases, the target propagation delay may further be determined based on a serving propagation delay between the serving cell and the mobile device. A target transmission time is calculated based on the target propagation delay. The mobile device uses the target transmission time to time align transmissions to the target cell during handover.