Patent Grant
9666990
The subject matter herein relates generally to electrical connectors that have signal and ground contacts.
Communication systems exist today that utilize electrical connectors to transmit data. For example, network systems, servers, data centers, and the like may use numerous electrical connectors to interconnect the various devices of the communication system. Many electrical connectors include signal conductors and ground conductors in which the signal conductors convey data signals and the ground conductors reduce crosstalk and/or electromagnetic interference (EMI) between the signal conductors. In differential signaling applications, the signal conductors are arranged in signal pairs for carrying the data signals. Each signal pair may be separated from an adjacent signal pair by one or more ground conductors.
There has been a general demand to increase the density of signal conductors within the electrical connectors and/or increase the speeds at which data is transmitted through the electrical connectors. As data rates increase and/or distances between the signal conductors decrease, however, it becomes more challenging to maintain a baseline level of signal integrity. For example, in some cases, electrical energy that flows through (for example, on the surface of) each ground conductor of the electrical connector may be reflected and resonate within cavities formed between ground conductors. Unwanted electrical energy, such as EMI, may be supported between nearby ground conductors. Depending on the frequency of the data transmission, electrical noise may develop that increases return loss and/or crosstalk and reduces throughput of the electrical connector.
Accordingly, there is a need for electrical connectors that reduce the electrical noise and interference caused by resonating conditions between ground conductors.
In an embodiment, a plug module is provided including a plug body having a terminating end configured to terminate to an electrical component and a mating end configured to mate with a mating electrical connector. The plug body has a first outer side and a second outer side. The plug body has pockets between the first and second outer sides. A plug shroud extends from the plug body at the terminating end. The plug shroud is configured to be coupled to the electrical component. A contact array is held by the plug body. The contact array has signal contacts and ground contacts interleaved between corresponding signal contacts. The signal and ground contacts are exposed along the first and second outer sides. At least some of the ground contacts are aligned with corresponding pockets. Resonance-control lossy inserts are provided in corresponding pockets adjacent corresponding ground contacts. The lossy inserts are manufactured from lossy material capable of absorbing electrical resonance propagating through the plug body.
In another embodiment, a plug connector is provided including a circuit board having a card edge between first and second sides of the circuit board. The circuit board has signal and ground conductors on the first and second sides of the circuit board proximate to the card edge. A plug module is coupled to the card edge of the circuit board. The plug module includes a plug body having a terminating end terminated to the card edge of the circuit board and a mating end configured to mate with a mating electrical connector. The plug body has a first outer side and a second outer side. The plug body has pockets between the first and second outer sides. A plug shroud extends from the plug body at the terminating end. The plug shroud receives the card edge of the circuit board. A contact array is held by the plug body. The contact array has signal contacts and ground contacts interleaved between corresponding signal contacts. The signal and ground contacts are exposed along the first and second outer sides. At least some of the ground contacts are aligned with corresponding pockets. The signal and ground contacts have terminating ends extending from the terminating end of the plug body. The terminating ends of the signal and ground contacts are terminated to corresponding signal and ground conductors of the circuit board. Resonance-control lossy inserts are provided in corresponding pockets adjacent corresponding ground contacts. The lossy inserts are manufactured from lossy material capable of absorbing electrical resonance propagating through the plug body.
In another embodiment, a plug connector is provided including a wire harness having a plurality of wires. A plug module is provided at the end of the wire harness. The plug module includes a plug body having a terminating end and a mating end opposite the terminating end configured to mate with a mating electrical connector. The plug body has a first outer side and a second outer side. The plug body has pockets between the first and second outer sides. A plug shroud extends from the plug body at the terminating end. The plug shroud defines a cavity receiving the wires of the wire harness. A contact array is held by the plug body. The contact array has signal contacts and ground contacts interleaved between corresponding signal contacts. The signal and ground contacts are exposed along the first and second outer sides. At least some of the ground contacts are aligned with corresponding pockets. The signal and ground contacts having terminating ends being electrically connected to corresponding wires of the wire harness. Resonance-control lossy inserts are provided in corresponding pockets adjacent corresponding ground contacts. The lossy inserts are manufactured from lossy material capable of absorbing electrical resonance propagating through the plug body.
Embodiments set forth herein may include various electrical connectors that are configured for communicating data signals. The electrical connectors may mate with a corresponding mating connector to communicatively interconnect different components of a communication system. In the illustrated embodiment, the electrical connector is a plug connector, which may be terminated to and electrically coupled to another electrical component, such as a circuit board, a wire harness or another electrical component. The plug connector may be a pluggable input/output (I/O) connector, which may be mated with a corresponding receptacle connector during a mating operation. It should be understood, however, that the inventive subject matter set forth herein may be applicable in other types of electrical connectors.
In various embodiments, the electrical connectors provide lossy ground inserts to provide resonance control. Moreover, in various embodiments, the electrical connectors are particularly suitable for high-speed communication systems, such as network systems, servers, data centers, and the like, in which the data rates may be greater than 5 gigabits/second (Gbps). However, one or more embodiments may also be suitable for data rates less than 5 Gbps.
In various embodiments described and/or illustrated herein, the electrical connectors include signal and ground conductors that are positioned relative to each other to form a pattern or array that includes one or more rows (or columns). The signal and ground conductors of a single row (or column) may be substantially co-planar. The signal and ground conductors may be vertical or straight conductors, may be right-angle conductors having a generally 90° bend along the length of the conductors, or may have other arrangements. The signal conductors may form signal pairs in which each signal pair is flanked on both sides by ground conductors. The ground conductors electrically separate the signal pairs to reduce electromagnetic interference or crosstalk and to provide a reliable ground return path. The signal and ground conductors in a single row are patterned to form multiple sub-arrays. Each sub-array includes, in order, a ground conductor, a signal conductor, a signal conductor, and a ground conductor. This arrangement is referred to as ground-signal-signal-ground (or GSSG) sub-array. The sub-array may be repeated such that an exemplary row of conductors may form G-S-S-G-G-S-S-G-G-S-S-G, wherein two ground conductors are positioned between two adjacent signal pairs. In the illustrated embodiment, however, adjacent signal pairs share a ground conductor such that the pattern forms G-S-S-G-S-S-G-S-S-G. In both examples above, the sub-array is referred to as a GSSG sub-array. More specifically, the term “GSSG sub-array” includes sub-arrays that share one or more intervening ground conductors.
In some embodiments, the electrical connector 104 may be part of a daughter card assembly that is configured to engage a backplane or midplane communication system (not shown). In various embodiments, the communication system 100 may include a plurality of the electrical connectors 104 mounted to the circuit board 102 along an edge of the circuit board 102 in which each of the electrical connectors 104 is configured to engage a corresponding pluggable input/output (I/O) mating electrical connector, such as the plug connector 108. The electrical connector 104 and plug connector 108 may be configured to satisfy certain industry standards, such as, but not limited to, the small-form factor pluggable (SFP) standard, enhanced SFP (SFP+) standard, quad SFP (QSFP) standard, C form-factor pluggable (CFP) standard, and 10 Gigabit SFP standard, which is often referred to as the XFP standard. In some embodiments, the plug connector 108 may be configured to be compliant with a small form factor (SFF) specification, such as SFF-8644 and SFF-8449 HD. The electrical connector 104 and the plug connector 108 may be high-speed electrical connectors that are capable of transmitting data at a rate of at least about five (5) gigabits per second (Gbps), at least about 10 Gbps, at least about 20 Gbps, at least about 40 Gbps, or more. Although not shown, the electrical connector 104 optionally may be positioned within a receptacle cage. The receptacle cage may be configured to receive the plug connector 108 during a mating operation and direct the plug connector 108 toward the electrical connector 104. The communication system 100 may also include other devices that are communicatively coupled to the electrical connector 104 through the circuit board 102. The electrical connector 104 may be located proximate to an edge of the circuit board 102.
The electrical connector 104 includes a housing 110 having a plurality of walls, including a first end 111, a second end 112, a front end 113, a rear end 114, a first side 115 and a second side 116. The housing 110 may include greater or fewer walls in alternative embodiments. The housing sides 115, 116 extend between the front and rear ends 113, 114 and the first and second ends 111, 112. The front end 113 and the rear end 114 face in opposite directions. The first and second sides 115, 116 face in opposite directions. The first and second ends 111, 112 face in opposite directions. The housing 110 extends a height between the first end 111 and the second end 112. The housing 110 extends a width between the front end 113 and the rear end 114. The housing 110 extends a length between the first and second sides 115, 116.
In the illustrated embodiment, the first end 111 defines a top end and may be referred to hereinafter as a top end 111 and the second end 112 defines a bottom end and may be referred to hereinafter as a bottom end 112. The bottom end 112 faces the board surface 106 and may be mounted to or engage the board surface 106. The top end 111 faces away from the circuit board 102 and may have the greatest elevation of the housing walls with respect to the board surface 106.
In the illustrated embodiment of
The housing 110 includes a mating slot 118 (
The receptacle connector 104 includes one or more contact arrays 120 having signal conductors 122 and ground conductors 124 that are held in the housing 110. In an exemplary embodiment, the signal and ground conductors 122, 124 are arranged in two rows on opposite sides of the mating slot 118, such as in an upper row and a lower row as in the illustrated embodiment. The signal and ground conductors 122, 124 are configured to be terminated to the circuit board 102. For example, terminating ends thereof may be soldered or welded to traces or contact pads (not shown) of the circuit board. Alternatively, the terminating ends may form compliant pins that are inserted into plated thru-holes (PTHs) (not shown) of the circuit board 102.
In an embodiment, the signal conductors 122 are arranged to form a plurality of signal pairs that are configured to carry differential signals. The ground conductors 124 are interleaved between the signal pairs of signal conductors 122. For example, the signal and ground conductors 122, 124 may be arranged in a plurality of ground-signal-signal-ground (GSSG) sub-arrays in which each pair of signal conductors 122 is located between two ground conductors 124. The signal pair in each GSSG sub-array is disposed between first and second ground conductors 124 that separate the corresponding signal pair from adjacent signal pairs.
The plug connector 108 is terminated to an electrical component 128 and is configured to mate with the electrical connector 104. The plug connector 108 is pluggable into the slot 118 of the receptacle connector 104 to provide an electrically conductive signal path across the connectors 104, 108 between the electrical component 128 and the circuit board 102. The plug connector 108 includes a plug body 130 having a terminating end 132 terminated to the electrical component 128 and a mating end 134 capable of mating with a mating connector, such as the electrical connector 104. The plug body 130 has a first outer side 136 and a second outer side 138 opposite the first outer side 136.
A plug shroud 140 extends from the plug body 130 at the terminating end 132. The plug shroud 140 is configured to be coupled to the electrical component 128. Optionally, the plug shroud 140 may be a separate component from the plug body 130 and mechanically secured thereto. For example, the plug shroud 140 may be a dielectric housing that receives and holds the plug body 130. The plug shroud 140 may receive or extend at least partially around a portion of the electrical component 128. For example, in an exemplary embodiment, the electrical component 128 includes a circuit board 142 coupled to the plug shroud 140 and/or the terminating end 132 of the plug body 130. An edge of the circuit board 142 may be received in the plug shroud 140. In other various embodiments, the plug shroud 140 may be part of the plug body 130 or the plug connector 108 may be devoid of the plug shroud 140.
A contact array 150 is held by the plug body 130. The contact array 150 has signal contacts 152 and ground contacts 154 interleaved between corresponding signal contacts 152. Optionally, the signal and ground contacts 152, 154 may be loaded into the plug body 130, such as being stitched into the plug body 130. Alternatively, the signal and ground contacts 152, 154 may be overmolded by at least one overmold body that defines the plug body 130. The signal and ground contacts 152, 154 are exposed along the first and second outer sides 136, 138. The signal and ground contacts 152, 154 are configured to be mated with both rows of signal and ground conductors 122, 124 of the electrical connector 104 when the plug body 130 is plugged into the mating slot 118. In other various embodiments, the signal and ground contacts 152, 154 may be provided on only one of the outer sides 136 or 138, such as for mating with a single row of signal and ground conductors 122, 124. The signal contacts 152 and the ground contacts 154 of the plug connector 108 may be arranged similar to the signal conductors 122 and the ground conductors 124, respectively, of the receptacle connector 104. For example, the signal and ground contacts 152, 154 may be arranged in at least one plug conductor array that includes a plurality of GSSG sub-arrays along a row.
In an exemplary embodiment, the plug connector 108 includes at least one resonance-control lossy insert 160 (shown in phantom in
The lossy insert 160 may be provided at any location along the length of the plug body 130, such as approximately centered between the terminating end 132 and the mating end 134. The lossy insert 160 may extend any depth within the plug body 130 between the first and second outer sides 136, 138 and may extend substantially the entire depth to couple to ground contacts 154 on both outer sides 136, 138. The lossy insert 160 may directly engage the ground contacts 154 or may be in close proximity such that the lossy insert 160 is capacitively or otherwise electrically coupled to the ground contacts 154. Optionally, the lossy insert 160 may span across all or a portion of the width of the plug body 130, such as to interface with multiple ground contacts 154 on the first outer side 136 and/or multiple ground contacts 154 on the second outer side 138. For example, the lossy insert 160 may pass across the signal contacts 152, within the thickness of the plug body 130, to ground contacts 154 on opposite sides of the signal contacts 152.
In an exemplary embodiment, the lossy insert 160 includes lossy material capable of absorbing at least some electrical resonance that propagates along the current paths defined by the signal contacts 152 and/or the ground contacts 154 through the electrical connector 108. For example, the lossy material may be embedded in the plug body 130. The lossy material has dielectric properties that vary with frequency. The lossy material provides lossy conductivity and/or magnetic lossiness through a portion of the electrical connector 104. The lossy material is able to conduct electrical energy, but with at least some loss. The lossy material is less conductive than conductive material, such as the conductive material of the contacts 152, 154. The lossy material may be designed to provide electrical loss in a certain, targeted frequency range, such as by selection of the lossy material, placement of the lossy material, proximity of the lossy material to the ground paths and the signal paths, and the like. The lossy material may include conductive particles (or fillers) dispersed within a dielectric (binder) material. The dielectric material, such as a polymer or epoxy, is used as a binder to hold the conductive particle filler elements in place. These conductive particles then impart loss to the lossy material. In some embodiments, the lossy material is formed by mixing binder with filler that includes conductive particles. Examples of conductive particles that may be used as a filler to form electrically lossy materials include carbon or graphite formed as fibers, flakes, or other particles. Metal in the form of powder, flakes, fibers, or other conductive particles may also be used to provide suitable lossy properties. Alternatively, combinations of fillers may be used. For example, metal plated (or coated) particles may be used. Silver and nickel may also be used to plate particles. Plated (or coated) particles may be used alone or in combination with other fillers, such as carbon flakes. In some embodiments, the fillers may be present in a sufficient volume percentage to allow conducting paths to be created from particle to particle. For example when metal fiber is used, the fiber may be present at an amount up to 40% by volume or more. The lossy material may be magnetically lossy and/or electrically lossy. For example, the lossy material may be formed of a binder material with magnetic particles dispersed therein to provide magnetic properties. The magnetic particles may be in the form of flakes, fibers, or the like. Materials such as magnesium ferrite, nickel ferrite, lithium ferrite, yttrium garnet and/or aluminum garnet may be used as magnetic particles. In some embodiments, the lossy material may simultaneously be an electrically-lossy material and a magnetically-lossy material. Such lossy materials may be formed, for example, by using magnetically-lossy filler particles that are partially conductive or by using a combination of magnetically-lossy and electrically-lossy filler particles
As used herein, the term “binder” encompasses material that encapsulates the filler or is impregnated with the filler. The binder material may be any material that will set, cure, or can otherwise be used to position the filler material. In some embodiments, the binder may be a thermoplastic material such as those traditionally used in the manufacture of electrical connector housings. The thermoplastic material may be molded, such as molding of the lossy insert 160 into the desired shape and/or location. However, many alternative forms of binder materials may be used. Curable materials, such as epoxies, can serve as a binder. Alternatively, materials such as thermosetting resins or adhesives may be used.
Electrical performance of the plug connector 108 is enhanced by the inclusion of the lossy material in the lossy inserts 160. For example, at various data rates, including high data rates, return loss is inhibited by the lossy material. For example, the return loss of the small pitch, high speed data of the contact arrays due to the close proximity of signal and ground contacts 152, 154 is reduced by the lossy inserts 160. For example, energy from the ground contacts 154 on either side of the signal pair reflected in the space between the ground contacts 154 is absorbed, and thus connector performance and throughput are enhanced.
The circuit board 142 is shown in
The plug shroud 140 includes a cavity 144 that receives the plug body 130. The cavity 144 may be open at the front and at the rear of the plug shroud 140. The plug shroud 140 includes rails 146 extending rearward from the main body of the plug shroud 140 that defines the cavity 144. Optionally, the main body may entirely surround the cavity 144 (for example, on four sides of the cavity 144). The rails 146 define a receiving space therebetween configured to receive the electrical component 128 (for example, the circuit board 142, a wire harness or another type of electrical component 128). In an exemplary embodiment, the rails 146 include slots 148 that receive the circuit board 142. For example, the card edge 170 of the circuit board 142 may be loaded into the slots 148 in the receiving space, such as for mating with the signal and ground contacts 152, 154. The plug shroud 140 may include locating features for guiding mating and/or positioning with the plug body 130 and/or with the receptacle connector 104 (shown in
The plug body 130 includes a front tray 180 that extends to the mating end 134 and a rear base 182 that extends to the terminating end 132. The front tray 180 and/or the rear base 182 may receive the lossy inserts 160. The front tray 180 is configured to be loaded into the mating slot 118 (shown in
A first array of the signal and ground contacts 152, 154 is disposed at least partially along the first outer side 136, and a second array of the signal and ground contacts 152, 154 is disposed at least partially along the second outer side 138. For example, the signal contacts 152 and the ground contacts 154 are arranged in repeating GSSG sub-arrays across a lateral width of the front tray 180. At least portions of the signal and ground contacts 152, 154 are exposed along the front tray 180 for mating with the signal and ground conductors 122, 124 (shown in
The signal and ground contacts 152, 154 have terminating ends 186 generally opposite the mating ends 184. In the illustrated embodiment, the terminating ends 186 extend rearward of and are cantilevered from the terminating end 132 of the plug body 130, such as for terminating to the circuit board 142. The terminating ends 186, in the illustrated embodiment, include spring beams 188 configured to engage the signal and ground conductors 172, 174 of the circuit board 142. For example, the spring beams 188 may be elastically deflected outward when the circuit board 142 is loaded into a receiving space 190 defined between the rows of signal and ground contacts 152, 154, thus forming an internal spring force that presses the spring beams 188 against the signal and ground conductors 172, 174 to maintain the electrical connection with the signal and ground conductors 172, 174. Alternatively, the terminating ends 186 may be provided on the first and second outer sides 136, 138, such as in the form of solder pads, for termination to the electrical connector (for example, the circuit board 142, a wire harness, or other type of electrical connector), such as through a direct or indirect electrical connection.
In an exemplary embodiment, the plug body 130 includes signal contact channels 192 that receive signal contacts 152 and ground contact channels 194 that receive ground contacts 154. The contact channels 192, 194 may be open at the terminating end 132, such as to receive the contacts 152, 154 therethrough. The contact channels 192, 194 may be open along at least parts of the lengths thereof to the outer sides 136, 138, such as to expose the mating ends 184 of the contacts 152, 154. The contacts 152, 154 may be loaded into the corresponding contact channels 192, 194 through the rear or through the outer sides 136, 138. Alternatively, the plug body 130 may be overmolded over the first array and/or the second array. For example, the plug body 130 may be formed from two separate overmolded bodies that are coupled together to form the plug body 130. Optionally, upper and lower bands 196 may cover portions of the contact channels 192, 194 and the contacts 152, 154, such as to retain the contacts 152, 154 in the contact channels 192, 194. For example, the bands 196 may be provided at the rear base 182. In an exemplary embodiment, the lossy inserts 160 are aligned with, and may be exposed along, the ground contact channels 194, such as to allow coupling with the ground contacts 154.
As the front tray 180 is loaded into the mating slot 118 in a mating direction, the signal and ground conductors 122, 124 are deflected outward. The deflection of the signal and ground conductors 122, 124 biases the conductors 122, 124 towards the corresponding signal and ground contacts 152, 154 of the plug connector 108 to retain electrical engagement therebetween. The engagement between the corresponding signal conductors 122 and signal contacts 152 provides electrical signal paths between and across the connectors 104, 108. The engagement between the corresponding ground conductors 124 and ground contacts 154 provides electrical shielding between the signal paths and also provides electrical grounding paths between and across the connectors 104, 108. The lossy inserts 160 are electrically coupled to the grounding paths to absorb electrical resonance propagating through the communication system 100. The lossy inserts 160 provide resonance control to reduce resonant frequency noise spikes, thereby improving the electrical performance of the mated connectors 104, 108.
In an exemplary embodiment, the plug connector 108 electrically couples resonance-control lossy inserts 160 to each ground contact 154. The lossy inserts 160 may be directly coupled to each ground contact 154 in various embodiments. Alternatively, the lossy inserts 160 may be indirectly coupled, such as by capacitive coupling or providing another conductor therebetween. In the illustrated embodiment, the lossy inserts 160 are received in pockets 200 in the plug body 130. The pockets 200 may be molded into the dielectric body of the plug body 130. The lossy inserts 160 may be molded into the pockets 200, such as injection molded. For example, the plug body 130 may be molded in a multi-shot molding process, such as a two-shot molding process, where the lossy inserts 160 are co-molded with the plug body 130 from different materials, such as a lossy material and a low loss plastic material, respectively. Alternatively, the lossy inserts 160 may be molded separately and inserted into the pockets 200 during an assembly process.
The pockets 200 may be open at inner ends 202 of the ground contact channels 194 to receive the lossy inserts 160. In the illustrated embodiment, the pockets 200 extend entirely through the plug body 130 between the first and second outer sides 136, 138 and are open to both ground contact channels 194 at the opposite sides 136, 138, and thus the lossy inserts 160 are positioned between the ground contacts 124 on both sides 136, 138. In an exemplary embodiment, the pockets 200 are discrete pockets separated by the low loss dielectric material of the plug body 130; however, in alternative embodiments, the pockets 200 may be interconnected, such as by a central pocket that connects some or all of the pockets 200. Such central pocket may be filled with lossy material and define a lossy insert that passes horizontally within the thickness of the plug body 130 between the signal contacts 152 to interconnect the vertical lossy inserts 160 associated with each of the ground contacts 154.
The lossy inserts 160 may have any shape, such as a narrow box-shape, as in the illustrated embodiment. The lossy inserts 160 each include at least one edge facing and, in various embodiments, engaging a corresponding ground contact 154. In an exemplary embodiment, each lossy insert 160 includes a first edge 204 engaging the ground contact 154 in the contact channel 194 at the first outer side 136, and a second edge 206 engaging the ground contact 154 in the contact channel 194 at the second outer side 138. The edges 204, 206 may be provided at the inner ends 202 (for example, coplanar with the inner ends 202) and may define at least portions of the surfaces of the inner ends 202. In the illustrated embodiment, the edges 204, 206 are substantially parallel to each other; however, other orientations are possible in alternative embodiments. The lossy inserts 160 may have a similar width as the ground contacts 154. The lossy inserts 160 may have locking features that lock the lossy inserts 160 in the pockets 200, such as protrusions, dimples or other features.
It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments, and are by no means limiting and are merely exemplary embodiments. Many other embodiments and modifications within the spirit and scope of the claims will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means-plus-function format and are not intended to be interpreted based on 35 U.S.C. §112(f), unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.
| Number | Name | Date | Kind |
|---|---|---|---|
| 7371117 | Gailus | May 2008 | B2 |
| 8083553 | Manter | Dec 2011 | B2 |
| 8177564 | Ito et al. | May 2012 | B1 |
| 8523583 | Ito | Sep 2013 | B2 |
| 8657627 | McNamara | Feb 2014 | B2 |
| 20070004282 | Cohen | Jan 2007 | A1 |
| 20090029602 | Cohen | Jan 2009 | A1 |
| 20090291593 | Atkinson | Nov 2009 | A1 |
| 20110287663 | Gailus | Nov 2011 | A1 |
| 20130012038 | Kirk | Jan 2013 | A1 |
| 20130109232 | Paniaqua | May 2013 | A1 |
| 20140004746 | Cartier, Jr. | Jan 2014 | A1 |
| 20140127946 | Ito et al. | May 2014 | A1 |
| 20150255904 | Ito | Sep 2015 | A1 |
