bra

YAW BRAKE SYSTEM

Disclosed herein is a yaw brake system including a multi-disk member disposed in an upper portion of a tower frame of wind generator and including at least two disks, and a braking member disposed in a lower end of a nacelle frame of the wind generator, and provided to brake yawing of a nacelle by interlocking with the multi-disk member. In accordance with the disclosure, it is possible to prepare for buildup of equipment, such as a blade, a hub, or a nacelle, depending on an increase in power of wind power generation, and at the same time to more effectively brake yawing of the nacelle due to a rapid change in wind direction while overcoming a limited space in the nacelle.




bra

INTERLOCK BRAKING SYSTEM

In an approach to interlock braking, one or more driving wheels and one or more driven wheels are engaged to rotate in the same first direction. One or more braking wheels are driven by a power transmission mechanism associated with the one or more driving wheels. A first braking surface, associated with the one or more driven wheels, and a second braking surface, associated with the one or more braking wheels, engage. A braking force is generated by the engagement of the first braking surface and the second braking surface, and transmitted by the power transmission mechanism to the one or more driving wheels.




bra

METHOD FOR MOUNTING A HYDRAULIC BRAKING APPARATUS ON A BICYCLE, HYDRAULIC BRAKING APPARATUS AND MOUNTING TOOL

A method for mounting a flexible tube associated with braking hydraulics on a bicycle between a braking control member and a braking member. The method provides a mounting cable for use in locating the flexible tube within a bicycle frame element while the ends of the flexible tube are exposed so a respective end can be connected to the control member and the braking member. The method simplifies the insertion process and reduces damage to the flexible tube. A tool for inserting the flexible tube is also provided.




bra

Disc Brake, Brake Caliper, and Brake Rotary Lever

A disc brake, preferably a compressed air-actuated disc brake, in particular for a motor vehicle, has a brake application mechanism with a brake rotary lever, at least one spindle unit having a threaded rod screwed into a bridge, and a brake caliper. The caliper frames an edge region of a brake disc. The brake caliper has a brake application portion and a caliper back which are connected together via tie bars. The brake application mechanism with the brake rotary lever is received in the brake application portion of the brake caliper from an application face side of the brake disc. The brake application portion of the brake caliper has a first region, in which the application mechanism and a force transmission portion of the brake rotary lever are arranged, a second region, which is formed as a lever housing, and a lever portion for the brake rotary lever. A support wall with a bearing portion, which forms a pivot bearing with a brake rotary lever axis that runs parallel to the brake disc, for the brake rotary lever is arranged between the first region and the second region.




bra

BRAKE PISTON

A brake piston includes a piston pocket. The piston pocket receives a nut that is axially movable along a center axis. The nut is restricted from rotating within the piston pocket when a torque due to a frictional engagement between a nut seal and an inner pocket wall, one or more projections, or both is greater than an input torque at the nut. The nut is rotatable within the piston pocket when a torque due to the frictional engagement between the nut seal and the inner pocket wall, the one or more projections or both is less than the input torque at the nut and is less than the torque due to the frictional engagement between the piston and the piston seal.




bra

BRAKE CALIPER WITH BRAKE PAD TIMING AND RETRACTION CONTROLLER WITH LOCK-CONNECTION

A brake caliper is provided with a timing and retraction controller, a brake pad and a lock-connection comprising an engaging component and a locking component. The timing and retraction controller adjusts brake timing, eliminates parasitic brake losses and dampens out-of-plane vibration between the brake pad and rotor. The brake caliper includes a housing disposed over a brake rotor; first and second opposing brake pads extendably and retractably mounted on opposite sides of the caliper housing, brake pistons that extend and retract the brake pads into and out of frictional engagement with the rotor, and brake pad timing and retraction controllers disposed on opposite sides of the caliper housing. Each controller includes a Belleville spring or other resilient member with a short compression travel limited to between about 1.50 mm and 0.025 mm. The short stroke Belleville spring of each controller applies a hold-off force against the extension force of the brake pistons that slightly delays brake pad extension and slightly reduces brake pad clamping force against the rotor, thereby advantageously providing a front wheel braking bias when applied to the rear wheels of a vehicle. The restorative force applied by the short stroke Belleville forcefully and uniformly retracts the brake pad from the rotor, eliminating parasitic brake losses, and dampening out-of-plane vibration between the brake pad and rotor.




bra

Adjusting Device for a Disc Brake, and Disc Brake with Such an Adjusting Device

An adjusting device for a disc brake, in particular for utility vehicles, is provided. The adjusting device includes a freewheel having an inner ring and an outer ring. The inner ring and outer ring together with multiple rolling bearing balls form an axial ball bearing. The inner ring is rotatably supported relative to the outer ring by the rolling bearing balls. The freewheel further has a cage in which multiple clamping rollers are biased with compression springs and compression pieces, the cage being arranged between the inner ring and the outer ring in a radial direction relative to a through-bore passing through the inner and outer rings. The compression springs may be pretensioned by rotating the cage relative to the inner ring and then fixing the cage to on the inner ring with a locking device.




bra

PAD FOR A BICYCLE DISC BRAKE AND DISC BRAKE COMPRISING SUCH A PAD

The invention relates to a pad for a bicycle disc brake, comprising a support frame and an element made of friction-wearing material associated with said support frame. The element made of friction-wearing material comprises a visual wearing indicator, which preferably is defined on an upper portion of the element made of friction-wearing material, more preferably at a side end area of said upper portion. The invention also relates to a bicycle disc brake comprising a pair of pads of the type described above.




bra

BRAKE DEVICE OF TRANSMISSION

A brake device of a transmission includes a first brake provided in a transmission including an outer cone and an inner cone, a second brake provided at one end of the first brake and operated at the time of a low stage or backward movement, and an elastic body provided between the first brake and the second brake to operate the first brake or the second brake depending on a spring load.




bra

RAIL VEHICLE BRAKE DISK

A one-piece rail vehicle brake disk is made of steel or cast iron, comprises at least one effective surface with which a friction element comes in contact during a braking maneuver, and is designed in such a way that the effective surface has a plurality of blind holes.




bra

ATTACHABLE HIGH-Mn STEEL BRAKE DISK

An attachable high-manganese steel brake disk includes a first disk member including air vents disposed radially therein to be spaced apart from each other, and a pair of second disk members installed to be attached to two surfaces of the first disk member and having a braking surface in contact with a brake pad. Between the first disk member and the second disk members, at least the second disk members are provided as high manganese steel members.




bra

ELECTRO-MECHANICAL BRAKE DEVICE

An electro-mechanical brake device may include: a driver configured to generate rotary power; a first gear connected to an output shaft of the driver, and the first gear configured to rotate with the output shaft; a second gear installed in a direction crossing the first gear, engaged with the first gear, and configured to rotate with the first gear; a third gear engaged with the second gear and configured to rotate with the second gear, the third gear having a rotating gear bar installed in parallel to the output shaft and configured to rotate with the output shaft; a moving nut engaged with the third gear and configured to move linearly; and a piston installed in a shape covering an outside of the moving nut, and pushed by the moving nut so as to pressurize a brake pad.




bra

Brake System

The invention relates to a brake system, in particular wedge drum brake for utility vehicles, comprising a transmission element and a piston element, wherein the transmission element is guided displaceably along a transmission axis, wherein the piston element is guided displaceably transversely with respect to the transmission axis, wherein the transmission element has a transmission surface which is oriented in an inclined manner with respect to the transmission axis, wherein the piston element is supported with a piston surface on the transmission surface, wherein a displacement of the transmission element along the transmission axis brings about a displacement of the piston element substantially transversely with respect to the transmission axis.




bra

Brake System

The present invention relates to a brake system comprising an actuating part and a brake part, the actuating part having a pressure chamber and a restoring section, the pressure chamber and the restoring section being separated from one another in a fluid-tight manner by way of a piston, it being possible for the piston to be fixed on an engagement element in such a way that a movement of the piston brings about a movement of the engagement element, the engagement element protruding into the brake part and having, in the brake part, a force section which is designed to transmit a force to a brake means, the brake part and the predominant part of the actuating part being arranged in a housing.




bra

ROLLATOR BRAKING SYSTEM

A rollator braking system for a rollator includes two handles, two brake lever assemblies, and two wires. The rollator includes a frame and a plurality of wheels attached to the frame for moving the rollator. The two handles are adjustably connected to the frame, and each handle including a gripping member. Each of the two brake lever assemblies include a bracket fixedly connected to the handle and a lever rotatably connected to the bracket to rotate towards and away from the gripping member when in an unlocked position, and fixedly connected to the bracket when in a locked position. Each of the two wires are operably connected between a lever assembly and a brake on one of the wheels such that when the lever is rotated towards the gripping member, the brake slows rotation of the wheel, and when the lever is in the locked position the brake stops the rotation of the wheel.




bra

MULTI-PIECE TORQUE TUBE ASSEMBLY TO MITIGATE VIBRATION

A torque tube for use in a disk brake system in accordance with various embodiments includes a backleg having a reaction plate and a foot extending axially away from the reaction plate. The torque tube also includes a barrel having a tubular structure having an axis and an inner surface configured to receive the foot.




bra

Surface Ventilated Disc Brake Rotor

A disc brake rotor including a hub portion and a brake disc is provided. The brake disc extends radially outward from the hub portion and includes an outboard disc face and an inboard disc face. A plurality of channels are disposed in the brake disc that are circumferentially spaced from one another. Any one channel in the plurality of channels is open to either the outboard disc face or the inboard disc face. The brake disc includes an outer ring and an inner ring that are circumferentially continuous and uninterrupted along at least the outboard disc face and the inboard disc face. The outer ring is radially spaced from the inner ring with the plurality of channels disposed radially between the outer ring and the inner ring. Advantageously, this arrangement increases shear strength of the brake disc while providing enhanced cooling.




bra

PISTON MANUFACTURING DEVICE, PISTON MANUFACTURING METHOD, PISTON AND DISC BRAKE

A piston manufacturing device includes a first forming device (42) configured to form an annular groove (61) in a piston (11), and a second forming device (52) configured to press an edge (15) of an opening (14) of the piston (11) toward other end side in an axial direction of the piston (11) and to form a thick section (65) extruded from an inner circumferential surface (12b) arranged between the edge (15) and the groove (61) toward an axial center side of the piston (11), wherein a recessed section (53) is formed at a portion of the second forming device (52) that is arranged to abut the edge (15) so that an inner circumferential side of the edge (15) is plastically deformed toward the other end side in an axial direction of the piston (11).




bra

Vehicle Disk Brake

The invention relates to a vehicle disk brake having a brake-application device which provides the braking force and which is composed of a force element, preferably a pressure medium cylinder, and of a pressure-boosting lever arrangement, and having a readjustment device for compensatory readjustment of the wear-induced air clearance of the brake. The readjustment device comprises, as constituent parts, a rotatably arranged drive element (25) which can be actuated by the brake-application device, a readjustment element (26) arranged rotatably on the same axis, and a transmission device arranged in the movement path between drive element (25) and readjustment element (26). To provide a vehicle brake which is equipped with a readjustment device for compensatory readjustment of the wear-induced air clearance and in which the readjustment means is of structurally simple design and has a small number of parts, the transmission device is in the form of a helical wrap spring (30) which, along a first helix section (31), is supported radially with respect to the drive element (25) and, along a second helix section (32), is supported radially with respect to the readjustment element (26), wherein the former radial support is realized at the inner side, and the latter radial support is realized at the outer side, of the wrap spring (30).




bra

FRICTION LINING AND BRAKE PAD FOR A BRAKING SYSTEM

A friction lining for a brake pad of a braking system includes a solid body of friction material having plurality of slots intersecting at a vortex zone formed as a circular recess in the friction lining. The slots open into the vortex zone at offset locations to promote circulation of air within the vortex zone. The slots extend along a horizontal arc that follows the curvature of a rotor of the braking system when in use. Vertical slots may be included that also open into the vortex zone at offset locations.




bra

RAILCAR BRAKE BEAM ASSEMBLY AND RELATED METHOD OF DESIGNING A RAILCAR BRAKE BEAM ASSEMBLY

A railcar brake beam assembly including a brake beam formation having a tension member, a compression member and strut, and with the strut defining an axis for the brake beam assembly. First and second brake head assemblies are disposed to opposite lateral sides of the axis, with each brake head assembly being operably carried by the brake beam formation and includes a guide member extending in a direction away from the axis. The first and second brake head assemblies are generally centered laterally relative to the axis of the brake beam assembly. A distal end of the guide member on the first brake head assembly is disposed a different lateral distance from the axis of the brake beam assembly than is a distal end of the guide member on the second brake head assembly to minimize lateral shifting movements while maintaining adequate clearances for permitting reciprocal moments of the brake beam assembly during application of braking forces. A method of designing a brake beam assembly for a railcar is also disclosed.




bra

MATERIALS FOR DAMPED HEATSINK DISK BRAKE ASSEMBLY

A friction disk brake system may comprise a plurality of rotor friction disks and a plurality of stator friction disks. At least one of the friction disks may be a split disk friction disk. The split disk friction disk may comprise a first disk half and a second disk half. A carbon foam damping feature may be located between the first disk half and the second disk half.




bra

PLATE ASSEMBLIES INCLUDING FLOATING WEAR LININGS FOR MULTI-DISK BRAKE SYSTEMS AND METHODS FOR REDUCING VIBRATION IN A MULTI-DISK BRAKE SYSTEM

A plate assembly for a multi-disk brake system is provided. The plate assembly includes at least one of a pressure plate or an end plate and a floating plate wear liner mounted against the at least one of the pressure plate or the end plate. The floating plate wear liner is configured to contact a contact surface of an adjacent rotatable friction disk in response to the multi-disk brake system being actuated.




bra

Brake Rotor With Working Surface Inserts

A brake rotor assembly can include a structural part having a receiving surface and at least one friction surface parts having a contact surface. The friction surface part can be fixably attached to the receiving surface of the structural part such that the contact surface faces away from the receiving surface of the structural surface to form at least part of an annular braking surface arranged concentrically around an axis of rotation of the structural part.




bra

NEEDLED BRAKE DISKS AND METHODS

The present disclosure provides a fibrous preform, comprising an annulus having at least one of an outer diameter portion or an inner diameter portion, the outer diameter portion extending radially inward from an outer diameter of the fibrous preform and the inner diameter portion extending radially outward from an inner diameter of the fibrous preform. In various embodiments, the fibrous preform further comprises a medial diameter portion disposed between the outer diameter and the inner diameter, wherein the medial diameter portion comprises a first needling profile, and the at least one of the outer diameter portion or the inner diameter portion comprises a second needling profile. In various embodiments, the first needling profile is less than the second needling profile.




bra

DISC BRAKE CALIPER

A disc brake (10) of the type including a pivoting lever having eccentric journals which act on a pair of tappets is disclosed. The tappets are adjusted in length by rotation, and each tappet has a tappet gear (22). A centrally located intermediate gear (24) is provided between the tappet gears to form a gear train, synchronizing the rotation of the two tappets and therefore ensuring that they remain the same length. The centrally located intermediate gear (24) includes a socket (26) for receiving a centrally located adjuster. The adjuster may be installed and removed from the disc brake through an aperture at the rear of the brake caliper, without any substantial disassembly of the brake and without de-synchronizing the tappets or even interrupting the gear train between the tappets.




bra

BRAKE PAD ASSEMBLY AND HEAT DISSIPATION STRUCTURE THEREOF

A heat dissipation structure for a brake pad is provided for being assembled to a caliper device. The caliper device includes a caliper body, and the caliper body has a receiving space. The heat dissipation structure includes: a main body, integrally extruded from aluminum and cut to have an ultimate appearance, including a plate body and a heat dissipation portion integrally extending from the plate body, the plate body for being disposed on the caliper body and at least partially extending into the receiving space, when the main body is assembled to the caliper body, the heat dissipation portion is exposed outside the caliper body. A brake pad assembly is further provided, including a heat dissipation structure as described above, further including a brake pad, the brake pad disposed on a lateral face of the plate body.




bra

BRAKE SHOE HAVING A WEAR INDICATOR

The invention relates to a brake shoe (1) for disk or drum brakes, which comprises a supporting plate (2) with a friction pad (3) attached thereto and at least one wear indicator (4), characterized in that the wear indicator (4) has a wear sensor (6) for continuous or multi-stage measurement of the wear of the friction lining and a receiver and transmitter unit (5) for wireless signal transmission, the receiver and transmitter unit being a passive RFID (Radio Frequency Identification) or SAW (Sound Acoustic Wave) transponder.




bra

Hydrogen membrane separator

The present application is directed to a hydrophobic membrane assembly (28) used within a gas-generating apparatus. Hydrogen is separated from the reaction solution by passing through a hydrophobic membrane assembly (28) having a hydrophobic lattice like member (36) disposed within a hydrogen output composite (32) further enhancing the ability of the hydrogen output composite's ability to separate out hydrogen gas and prolonging its useful life.




bra

Shock and Vibration Resistant Bulkhead Connector with Pliable Contacts

A high pressure and temperature, hermetically sealed bulkhead connector with pin and socket contacts for use in logging tools is described. The bulkhead connector comprises (a) one or more contact(s) placed within one or more channels wherein the channels provide a clearance path between contact(s) and bulkhead body and travel at least a partial longitudinal distance between proximal and distal ends. The contact(s) reside in the channel(s) and include at least; an optional movement limiter section, one central elongated section, and one fixed section where the contact(s) is attached to the bulkhead body at the distal end. The body correctly positions respective ends of the contact so that the body secures contact(s) to be parallel to each other and the contact(s) have terminal ends for connection. This arrangement provides at least one pivotable, pliable, free floating contact extending away from the fixed distal end of the bulkhead body.




bra

Nano-fabricated structured diamond abrasive article

The present invention describes a microfabricated or nanofabricated structured diamond abrasive with a high surface density array of geometrical protrusions of pyramidal, truncated pyramidal or other shape, of designed shapes, sizes and placements, which provides for improved conditioning of CMP polishing pads, or other abrasive roles. Three methods of fabricating the structured diamond abrasive are described: molding of diamond into an array of grooves of various shapes and sizes etched into Si or another substrate material, with subsequent transferal onto another substrate and removal of the Si; etching of an array of geometrical protrusions into a thick diamond layer, and depositing a thick diamond layer over a substrate pre-patterned (or pre-structured) with an array of geometrical protrusions of designed sizes, shapes and placements on the surface.




bra

Melamine methylol for abrasive products

An abrasive product includes a plurality of abrasive particles and a resin binder cured from a resin composition that includes an aqueous dispersion of melamine methylol having a melamine-to-formaldehyde molar equivalent ratio of between about 1:1 and about 1:3.2, wherein the aqueous dispersion has a pH in a range of between about 8 and about 10. The composition also includes a formaldehyde-based resins, such as a urea-formaldehyde resin or phenol-formaldehyde resin. The melamine methylol comprises between about 1 wt % and about 50 wt % of the combined weight of the formaldehyde-based resin and the melamine methylol.




bra

High porosity abrasive articles and methods of manufacturing same

An abrasive article includes a polymer matrix and abrasive grains dispersed in the polymer matrix, wherein the abrasive article has a void volume of at least 50%. The polymer matrix is polymerized from a monomer including at least one double bond.




bra

Abrasive articles including abrasive particles of silicon nitride

An abrasive article includes a body having abrasive particles contained within a bond material. The abrasive particles can include a majority content of silicon nitride and a minority content of sintering material including at least two rare-earth oxide materials. In an embodiment, the rare-earth oxide materials can include Nd2O3 and Y2O3. In a particular embodiment, the abrasive particles comprise a content (wt %) of Nd2O3 that is greater than a content of Y2O3 (wt %).




bra

Bonded abrasive article and method of forming

A method of forming an abrasive article includes providing a green body having abrasive particles including microcrystalline alumina, and heating the green body via microwave radiation to form a bonded abrasive body including the abrasive particles and a bond material comprising a vitreous phase.




bra

Imide cross-linked binders for abrasive articles

An abrasive article includes a fibrous substrate, a binder disposed on the fibrous substrate, and abrasive grains in contact with the binder. The binder includes an imide cross-linked urethane derived from a blocked isocyanate component and an anhydride component.




bra

Abrasive article for use in grinding of superabrasive workpieces

An abrasive article including a bonded abrasive having a body formed of abrasive grains contained within a bond material, wherein the body grinds a superabrasive workpiece having an average Vickers hardness of at least about 5 GPa at an average specific grinding energy (SGE) of not greater than about 350 J/mm3, at a material removal rate of at least about 8 mm3/sec, and wherein grinding is a centerless grinding operation.




bra

Superabrasive cutting element and manufacturing method with high degree of control of distribution and crystallographic orientation of the micro cutting edges

An abrasive element comprises a body of crystalline abrasive material. The body has an array of cutting elements formed of crystalline abrasive material which projects from a surface of the body. The shape, size and form of the projections is controlled in the production process. The body may be a natural or synthetic crystal. The body may be a film formed by deposition. The body may be diamond or cubic boron nitride. The body may be monocrystalline or polycrystalline. The projections may be aligned along a crystallographic plane or planes.




bra

Bonded abrasive article and method of forming

An abrasive article having an abrasive body including abrasive grains contained within a bond material, wherein the abrasive grains comprise microcrystalline alumina, and wherein the bond material includes less than about 1.0 mol % phosphorous oxide (P2O5), and a ratio measured in mol % between a total content of sodium oxide (Na2O) and a total content of potassium oxide (K2O) defined by [K2O/Na2O] having a value greater than about 0.5.




bra

Cleaning material and abrasive material made from bamboo fiber

The present invention discloses a cleaning cloth, an abrasive cloth, a cleaning buff and an abrasive buff which are each formed by knitting/weaving bamboo fibers having excellent cleaning, abrasive capacity and excellent ignition resistance.




bra

Fixed abrasive pad and method for forming the same

A fixed abrasive pad includes a substrate and a plurality of discrete abrasive blocks attached thereon, wherein the abrasive blocks comprise a plurality of abrasive sub-layers, wherein the abrasive density of the sub-layers increases layer-by-layer from the top sub-layer to the bottom sub-layer according to a predetermined ratio. The predetermined ratio ranges from about 1.099 to about 1.124.




bra

Abrasive grains based on zirconia alumina

Disclosed herein are abrasive grains based on zirconia alumina melted in an electric arc furnace, comprising a content of 52 to 62 wt % Al203 and 35 to 45 wt % ZrO2, wherein the high-temperature phases of the zirconia are stabilized by a combination of reduced Ti compounds and yttrium oxide.




bra

Methods for orienting superabrasive particles on a surface and associated tools

Methods of making a superabrasive tool precursor are disclosed, along with such precursors and associated tools. Particularly, methods are disclosed for orienting superabrasive particles in a viscous binding material in order to provide tools based thereupon and having desired performance characteristics.




bra

Abrasive particles having particular shapes and methods of forming such particles

An abrasive article includes a shaped abrasive particle including a body having a first height (h1) at a first end of the body defining a corner between an upper surface, a first side surface, and a second side surface, and a second height (h2) at a second end of the body opposite the first end defining an edge between the upper surface and a third side surface, wherein the average difference in height between the first height and the second height is at least about 50 microns. The body also includes a bottom surface defining a bottom area (Ab) and a cross-sectional midpoint area (Am) defining an area of a plane perpendicular to the bottom area and extending through a midpoint of the particle, the body has an area ratio of bottom area to midpoint area (Ab/Am) of not greater than about 6.




bra

Polishing composition and method utilizing abrasive particles treated with an aminosilane

The inventive method comprises chemically-mechanically polishing a substrate with an inventive polishing composition comprising a liquid carrier and abrasive particles that have been treated with a compound.




bra

Abrasive articles including abrasive particles bonded to an elongated body, and methods of forming thereof

An abrasive article includes an elongated body, a bonding layer including a metal overlying a surface of the elongated body, and a coating layer including a polymer material overlying the boding layer. The abrasive article further includes abrasive grains contained within the bonding layer and coating layer, and wherein the bonding layer comprises an average thickness (tbl) at least about 40% of the average grit size of the abrasive grains.




bra

Method for producing abrasive grains, method for producing slurry, and method for producing polishing liquid

In the production method for abrasive grains according to the invention, an aqueous solution of a salt of a tetravalent metal element is mixed with an alkali solution, under conditions such that a prescribed parameter is 5.00 or greater, to obtain abrasive grains including a hydroxide of the tetravalent metal element.




bra

Shaped abrasive particles and method of making

A method of making shaped abrasive particles including forming an abrasive flake comprising a plurality of precursor shaped abrasive particles and a frangible support joining the precursor shaped abrasive particles together; transporting the abrasive flake through a rotary kiln to sinter the abrasive flake; and breaking the sintered abrasive flake into individual shaped abrasive particles. The method is useful to make small shaped abrasive particles having insufficient mass to be efficiently individually sintered in a rotary kiln without joining two or more of the shaped abrasive particles together.




bra

Hierarchically Elaborated Phased-Array Antenna Modules and Method of Calibration

An apparatus consisting of hierarchically elaborated antenna modules is calibrated by steps. Although the AWV can be calculated mathematically based on the required phase shift values of each antenna element for a beam direction to compensate for signal delay. However, in practice, due to hardware implementation imperfection, coupling in signal path for each antenna element within hardware, inaccuracies of implementations, physical misalignment, the mathematically generated AWV does not necessarily provide alignment between transmit beam and receive beam. This subset is sufficient is all practical operation. The subset of AWVs are typically called codebook and the receiver beam points to different direction by using a AWV within the codebook.




bra

Final fabrication and calibration steps for hierarchically elaborated phased-array antenna and subarray manufacturing process

A process writes phase shift error correction values into a phased-array antenna to normalize a range of manufacturing variances. An axial ratio is determined for an antenna weight vector (AWV) by making multiple measurements with the horn of a test antenna mechanically rotating from 0 to 180 degree or with dual polarization test antenna. For calibration of the whole array, each subarray is treated in the same fashion as equivalent to an antenna element in the subarray calibration. The subarray is electronically rotated as a whole (all elements rotated by the same phase shift value) from 0 to 360 degree during the full array calibration. Due to small power variation among AWVs, calibration solely by REV results fail to consistently converge to resolution. Accordingly, the apparatus measures and compares axial ratios. During final fabrication, the apparatus programs an AWV with best axial ratio into each non-transitory array element.