External antenna for portable communication device

Abstract

A method of constructing an antenna (105) of a portable communication device (100). The method comprises: winding the conductive element (210) around the flexible support (215); coupling the conductive element (210) and the flexible support (215) to the rigid connector (230) to assemble the antenna core (205); and coating the antenna core (205) with a room temperature vulcanized (RTV) silica gel layer (705). The method further includes fitting the first half (200A) of the silicone rubber jacket (200) and the second half (200B) of the silicone rubber jacket (200) around the antenna core (205), compression molding the first half (200A) of the silicone rubber jacket (200) and the second half (200B) of the silicone rubber jacket (200) around the antenna core (205), and bonding the silicone rubber jacket (200) to the antenna core (205) through an RTV silicone layer (705).

Description

BACKGROUND OF THE DISCLOSURE

[0001] The present disclosure relates to an external antenna for a portable communication device, such as a land mobile radio. BRIEF DESCRIPTION OF THE DRAWINGS

[0002] The drawings, in which like reference numerals refer to the same or functionally similar elements throughout the separate views, are incorporated in and form a part of the specification, and are used to further illustrate embodiments, examples, aspects, and features of the claimed subject matter and to explain various principles and advantages of those embodiments, examples, aspects, and features.

[0003] Figure 1 is a perspective view of a portable communication device in accordance with some aspects.

[0004] Figure 2 is in accordance with some aspects including Figure 1 an exploded view of an antenna in a portable communication device.

[0005] Figure 3 is in accordance with some aspects including Figure 2 an exploded view of a connector assembly in the antenna.

[0006] Figure 4 is in accordance with some aspects including Figure 1 an exploded view of an antenna in a portable communication device.

[0007] Figure 5 shows the dispensing of an adhesive material onto the core of an antenna in accordance with some aspects in Figure 4 the antenna.

[0008] Figure 6 shows coating the core of an antenna with an adhesive material in accordance with some aspects in Figure 4 the antenna.

[0009] Figure 7 is in accordance with some aspects including Figure 1 a block diagram of an antenna in a portable communication device.

[0010] Figure 8 is in accordance with some aspects including Figure 1 a block diagram of an antenna in a portable communication device.

[0011] Figure 9 is a graph showing the results of a first flexibility test performed on various external antennas in accordance with some aspects.

[0012] Figure 10 is a graph showing the results of a second flexibility test performed on various external antennas in accordance with some aspects.

[0013] Figure 11 is a flowchart of an example method for constructing an antenna according to some aspects.

[0014] Those skilled in the art will understand that, for simplicity and clarity, the elements in the drawings are shown and need not be drawn to scale. For example, the dimensions of some elements in the drawings may be enlarged relative to other elements to help improve the understanding of embodiments, examples, aspects, and features.

[0015] In appropriately representing device and method components by conventional symbols in the drawings, only those specific details relevant to understanding the various embodiments, examples, aspects, and features are shown, so as not to obscure the present disclosure with details that would be obvious to those of ordinary skill in the art benefiting from the description herein. Detailed Description

[0016] Portable communication devices (e.g., land mobile radios (LMRs)) are used by first responders such as police, firefighters, and medical personnel. These devices are often exposed to the sun, water, dirt, wind, rain, snow, extreme temperatures, and other environmental conditions, as well as various physical stresses (e.g., dropping, vibration, etc.). The environmental conditions and physical stresses may cause damage to one or more components of the portable communication device. For example, the device antenna may be damaged. A device with a damaged antenna may operate poorly or become inoperable. Thus, portable communication devices designed to be used by first responders are designed to meet various safety standards to ensure the reliable operation of the portable communication device. For example, the National Fire Protection Association (NFPA) requires that the antennas included in portable communication devices used by firefighters be operable to withstand various stress tests, including drop tests, thermal tests, heat and immersion tests, direct flame tests, and tumble tests.

[0017] Existing antenna designs for portable communication devices used by first responders sometimes fail to meet the above stress test requirements of the NFPA. In addition, existing antenna designs for portable communication devices used by first responders are sometimes made of rigid materials. Rigid materials may be damaged and worn after repeated use. Thus, a flexible and durable external antenna design that can withstand the various stress test requirements of the NFPA is desired.

[0018] One aspect provides an antenna for a portable communication device. The antenna includes an antenna core that includes a conductive antenna element coupled to a flexible support and a rigid connector coupled to the conductive antenna element and the flexible support. The antenna also includes a silicone rubber sheath surrounding the antenna core and a room temperature vulcanizing (RTV) silicone layer positioned between the antenna core and the sheath that bonds the antenna core to the sheath.

[0019] On the other hand, a method of constructing an antenna for a portable communication device is provided. The method includes: winding a conductive element around a flexible support; coupling the conductive element and the flexible support to a rigid connector to assemble an antenna core; and coating the antenna core with a room temperature vulcanizing (RTV) silicone layer. The method further includes assembling a first half of a silicone rubber sheath and a second half of the silicone rubber sheath around the antenna core, compression molding the first half of the silicone rubber sheath and the second half of the silicone rubber sheath around the antenna core, and bonding the silicone rubber sheath to the antenna core through the RTV silicone layer.

[0020] Figure 1 is a perspective view of an exemplary communication device 100, which may be interchangeably referred to hereinafter as device 100. In the illustrated example, the communication device 100 includes features useful to a first responder and is otherwise configured to be used in environmental conditions frequently encountered by a first responder. In Figure 1 the example of, device 100 is a land mobile radio (LMR) that includes an external antenna. However, device 100 may be configured to communicate using other communication protocols and need not be configured to be used by a first responder.

[0021] Device 100 particularly includes an antenna 105, an antenna socket 110, and a radio transceiver 115. In some cases, the antenna 105 is removably coupled to the device 100 via the antenna socket 110. For example, in some cases, the antenna 105 is removably coupled to the device 100 via the antenna socket 110, using a twisting motion to remove and attach the antenna 105. In other cases, the antenna 105 is removably coupled to the device 100 using a different attachment mechanism and / or a corresponding motion. In some cases, the antenna 105 is permanently coupled to the device 100 through the antenna socket 110.

[0022] The radio transceiver 115 is shown in dashed lines to indicate that the radio transceiver 115 is inside the device 100. The radio transceiver 115 is connected to the antenna 105 via the antenna socket 110, enabling the radio transceiver 115 to perform wireless communication via the antenna elements included in the antenna 105. In some cases, the radio transceiver 115 includes, for example, a digital mobile radio (DMR) transceiver, a Project 25 (P25) transceiver, a trunked radio (TETRA) transceiver, a Bluetooth transceiver, a Wi-Fi transceiver, etc. that operate according to the IEEE 802.11 standard (e.g., 802.11a, 802.11b, 802.11g), such as an LTE (Long Term Evolution) transceiver that operates according to the IEEE 802.16 standard and / or other types of GSM (Global System for Mobile Communications) transceivers, a Worldwide Interoperability for Microwave Access (WiMAX) transceiver, and / or another similar type of wireless transceiver configurable to communicate via a wireless radio network.

[0023] Although not shown, the device 100 may include an electronic processor and a memory (e.g., a computer-readable storage medium). The electronic processor executes the instructions stored in the memory to control the operation of the radio transceiver 115. For example, the electronic processor controls the frequency range of operation of the radio transceiver 115. In some cases, the antenna 105 includes a multi-band antenna configured to operate on multiple frequency bands. In such a case, the processor may control the frequency range of operation of the radio transceiver 115 based on one or more inputs. In other cases, the antenna 105 is one of a plurality of antennas removably attached to the device 100, and each of the plurality of antennas is configured to operate under different (or the same) frequency bands. In some cases, frequencies in the range of approximately 100 MHz to approximately 900 MHz are used. In such a case, the processor controls the frequency range of operation of the radio transceiver 115 based on the operating frequency of the antenna 105 coupled to the device 100.

[0024] In the example shown, the device 100 also includes an accessory device, such as a microphone 120 connected to the device 100 via a cable 125. In other cases, the device 100 includes one or more additional accessory devices that are not microphones. In other cases, the device 100 does not include an accessory device.

[0025] Figure 2A exploded view of antenna 105 is shown. In the example shown, antenna 105 includes an outer sheath 200 and an antenna core 205. As will be described in more detail below, outer sheath 200 includes a first half 200A and a second half 200B compression molded around antenna core 205 during the construction of antenna 105. Outer sheath 200 is formed of a flexible silicone rubber material rated to withstand the various stress tests imposed by NFPA. For example, the silicone rubber material used to form outer sheath 200 is heat-cured or solid silicone rubber. A non-limiting example of a specific silicone rubber used to form outer sheath 200 is KE-581U manufactured by Shin-Etsu Chemical Co. TM The silicone rubber material used to form outer sheath 200 has good heat resistance and low dielectric loss components. Thus, outer sheath 200 is preferably rated to withstand the high temperature requirements of NFPA (e.g., 500 to 2,100 degrees Fahrenheit) and shield the signals transmitted and received by antenna 105 from electromagnetic interference.

[0026] Antenna core 205 includes an antenna conductor 210, a flexible support 215, a floating antenna element 220, a spacer 225, and a connector assembly 230. In the example shown, antenna conductor 210 is a helical coil wound around flexible support 215. However, in some cases, antenna conductor 210 is not wound around flexible support 215 and is coupled to flexible support 215 in a different manner. For example, in some cases, antenna conductor 210 is implemented as one or more of a straight antenna element, a monopole antenna element, a folded monopole antenna element, and / or a combination of a straight antenna element and a helical antenna element. Antenna conductor 210 is formed of one or more flexible conductive materials, such as copper, brass, bronze, and / or aluminum. In some cases, conductor 210 is a flexible printed circuit board. For example, in such cases, conductor 210 includes a copper inner layer and a polyamide outer layer.

[0027] Flexible support 215 is formed of one or more flexible materials, such as polyamide, liquid silicone rubber, compression silicone rubber, ethylene propylene diene monomer (EPDM) rubber, and / or glass-filled nylon. In some cases, one or more additional silicone materials are used to form flexible support 215. Similar to the silicone rubber material used to form outer sheath 200, the flexible materials used to form flexible support 215 are preferably rated to withstand high temperature requirements (e.g., 500 to 2,100 degrees Fahrenheit).

[0028] When assembling the antenna core 205, the floating antenna element 220 is inserted into the flexible support 215 and spaced apart from the connector assembly 230 by a spacer 225. For example, the flexible support 215 includes an internal channel along its longitudinal axis into which the floating antenna element 220 is inserted. When inserted into the flexible support 215, the floating antenna element 220 is not electrically connected in current to other electrical components of the antenna 105. However, the floating antenna element may be capacitively connected to other electrical components of the antenna 105, such as the antenna conductor 210. In some cases, the floating antenna element 220 is implemented as a monopole antenna element and / or a folded monopole antenna element. When the floating antenna element 220 is inserted into the flexible support 215, the spacer 225 supports the floating antenna element 220. The spacer 225 is formed of an insulating material and / or a dielectric material, such as Teflon TM material. In some cases, the antenna core 205 does not include the floating antenna element 220.

[0029] The connector assembly 230 is used to couple the antenna 105 to the device 100 via the antenna socket 110. In addition, the connector assembly 230 electrically connects the antenna 105 to the radio transceiver 115. For example, the connector assembly 230 includes one or more electrical connectors and / or signal pins that electrically connect the antenna conductor 210 and / or the floating antenna element 220 to the radio transceiver 115. In some cases, the connector assembly 230 does not include any internal circuitry, such as a matching circuit. In other cases, the connector assembly 230 includes one or more matching circuits.

[0030] Figure 3 A exploded view of the connector assembly 230 according to one example is shown. Among other things, the connector assembly 230 includes a base 300, an electrical connector 305, a matching circuit 310 removably positioned between the electrical connector 305 and the antenna conductor 210 when assembling the antenna core 205, and a housing 315 removably attached to the base 300 and arranged to enclose and protect the matching circuit 310. When assembling the antenna core 205, the electrical connector 305 is electrically connected to the antenna conductor 210 and / or the floating antenna element via the matching circuit 310. In some cases, the electrical connector is integrated with and / or includes the signal pin 320.

[0031] As shown in the figure, the base 300 includes a first thread 325 that extends (and / or extends internally into the antenna 105) towards the matching circuit 310, and a second thread 330 that extends away from the matching circuit 310. The threads 325, 330 are separated on the base 300 by a circular lip and / or flange 335. In some cases, the base 300 including the threads 325, 330 and the circular lip and / or flange 335 is formed of metal as an integrated unit. The housing 315 includes complementary threads 340 that removably mate with the first thread 325 of the base 300. Thus, during the assembly of the connector assembly 230, the housing 315 is screwed onto the base 300 via the threads 325, 340 and abuts against the inner side of the circular flange 335.

[0032] The second thread 330 is arranged to mate with the antenna socket 110 (e.g., at the complementary threads of the antenna socket 110). Thus, during the attachment of the antenna 105 to the communication device 100, the antenna 105 is screwed into the antenna socket 110 via the thread 330 (and the complementary threads at the antenna socket 110). When the antenna socket 110 is attached to the device 100, the antenna socket 110 abuts against the outer side of the circular flange 335.

[0033] The base 300 and the housing 315 are formed of one or more conductive metals. Thus, when the antenna 105 is attached to the device 100, the housing 315 is electrically connected to the antenna socket 110. The housing 315 is electrically isolated from the antenna conductor 210, the electrical connector 305, and the matching circuit 310. In addition, the housing 315 is rigid and surrounds the matching circuit 310 to mechanically protect the matching circuit 310. In some cases, when the connector assembly 230 is coupled to the device 100, the housing 315 grounds the antenna conductor 210 and / or the matching circuit 310. In some cases, additional ground antenna elements connected to the housing 315 can be wound around a flexible support 215, e.g., to have a double helix arrangement with the depicted helical antenna conductor 210 (e.g., the ground antenna is also helical and electrically isolated from the helical antenna conductor 210).

[0034] The matching circuit 310 includes a printed circuit board (PCB) 345, on which the radio frequency (RF) matching electrical components of the matching circuit 310 are mounted. Since the antenna conductor 210 can operate on multiple frequency bands, when the antenna 105 is attached to the device 100, the radio transceiver 115 wirelessly operates on multiple frequency bands via the antenna conductor 210 and the matching circuit 310. Accordingly, the matching circuit 310 is configured to perform radio frequency (RF) matching between the radio transceiver 115 and the antenna conductor 210 on multiple frequency bands. The housing 315 encloses the matching circuit 310 and the PCB 345 to physically protect the matching circuit 310 and the PCB 345 from damage during stress tests (e.g., drop tests or tumble tests) of the antenna 105 and / or the device 100.

[0035] The connector assembly 230 further includes a socket 350 for removably receiving the PCB 345. The socket 350 includes one or more slots 355 (such as at least two slots 355 as depicted) in which the PCB 345 is removably received. The socket 350 further includes holes 360 through which the signal pins 320 extend. As shown, the signal pins 320 are configured to removably mate with the matching circuit 310 when the PCB 345 is received in the socket 350 (e.g., in the slots 355). The signal pins 320 include corresponding slots 365 that extend into the socket 350, for example, between the slots 355, and removably receive the ends of the PCB 345. The ends of the PCB 345 received at the slots 365 include electrical connections 370 to the RF components of the matching circuit 310, which electrically connect the matching circuit 310 to the electrical connector 305 and / or the signal pins 320. As shown, the sides of the PCB 345 are slid into the slots 355 of the socket 350, which may include metal contacts electrically connected to the base 300 and / or the housing 315.

[0036] The connector assembly 230 further includes an insulating spacer 375 that is received in a hole 380 formed in the base 300 (e.g., at the inner side of the base 300). The spacer 375 includes corresponding holes 385 in which the signal pins 320 are received such that the electrical connector 305 and the signal pins 320 are electrically isolated from the base 300. When the antenna 105 is attached to the device 100, the electrical connector 305 is electrically connected to the radio transceiver 115 and the base 300 is grounded.

[0037] The matching circuit 310 also includes corresponding signal pins 390 that extend toward the antenna conductor 210 (e.g., when the antenna 105 is assembled). As shown, the signal pins 390 extend from the PCB 345 at an end opposite the end where the electrical connection 370 is located and / or where the PCB 345 is received in the slot 355 of the socket 350. The heads of the signal pins 390 include opposing biasing portions that can be compressed toward each other to mate with a conductive socket that receives the corresponding signal pin 390. The conductive socket is configured to removably receive the signal pin 390 and is electrically connected to the antenna conductor 210 such that the signal pin 390 and the antenna conductor 210 are electrically connected via the conductive socket.

[0038] The connector assembly 230 also includes a dielectric member 391 that is configured to removably mate with and / or be removably attached to the housing 315. For example, the dielectric member 391 mates with the housing 315 via threads 392 located at the housing end of the dielectric member 391. The threads 392 removably mate with complementary threads ( Figure 3 not visible in) at the inner surface of the housing 315.

[0039] As described above, the dielectric member 391 also includes a conductive socket formed therein ( Figure 3 not visible in) that is configured to removably mate with and be electrically connected to the matching circuit 310 via the signal pin 390. In addition, the matching circuit 310 and the antenna conductor 210 are electrically connected via the conductive socket inside the dielectric member 391. For example, the dielectric member 391 includes electrical contacts 393 at the outer surface 394 such that the matching circuit 310 and the antenna conductor 210 are electrically connected via the conductive socket and the electrical contacts 393. The signal pin 390 is connected to the conductive socket inside the dielectric member 391 (e.g., via a hole 395 in the dielectric member 391 at the end attached to the housing 315) that is electrically connected to the electrical contacts 393 at the end connected to the antenna conductor 210.

[0040] The dielectric member 391 additionally acts as a partially flexible mechanical interface between the rigid housing 315 and the antenna conductor 210 and the flexible support 215. For example, as Figure 3 shown, the dielectric member 391 also includes a mechanical connector 396 at the antenna end opposite the housing end of the dielectric member 391 that mates with and supports the flexible support 215.

[0041] Figure 4 An exploded view of the antenna 105 with the antenna core 205 assembled therein is shown. That is, Figure 4A exploded view of antenna 105 is shown, where antenna conductor 210 and flexible support 215 are coupled to connector assembly 230 (e.g., via mechanical connector 396) to form antenna core 205. Additionally, although Figure 4 not shown in Figure 4 , for examples where antenna 105 includes a floating antenna element, when assembling antenna core 205, floating antenna element 220 is inserted into flexible support 215.

[0042] Before compression molding the first half 200A and second half 200B of outer sheath 200 around the assembled antenna core 205, an adhesive bonding material layer is coated on antenna core 205. When compression molding the first half 200A and second half 200B around antenna core 205, the bonding material is used to bond antenna core 205 to outer sheath 200. In some cases, before compression molding the first half 200A and second half 200B of outer sheath 200 around antenna core 205, the bonding material is coated on antenna core 205 at a specific temperature or within a specific temperature range. In some cases, the adhesive material is a room temperature curing adhesive material.

[0043] In some cases, the entire exterior of antenna core 205 (e.g., antenna conductor 210, flexible support 215, and connector assembly 230) is coated with the same adhesive material. In other cases, before compression molding the first half 200A and second half 200B of the outer sheath around antenna core 205, antenna conductor 210 and flexible support 215 are coated with a first bonding material, and connector assembly 230 is coated with a second bonding material different from the first bonding material. In such cases, the first bonding material is selected as the bonding material most suitable for bonding antenna conductor 210 and / or flexible support 215 to outer sheath 200, and the second bonding material is selected as the bonding material most suitable for bonding the metal housing 315 of connector assembly 230 to outer sheath 200.

[0044] In some cases, the first bonding material coated on antenna conductor 210 and / or flexible support 215 is room temperature vulcanized (RTV) silicone. RTV silicone is most suitable for bonding flexible support 215 to silicone rubber outer sheath 200, and flexible support 215 as described above can be formed from one or more of polyamide, liquid silicone rubber, and / or glass filled nylon. When compared with other bonding and / or adhesive materials (e.g., epoxy resin), when compression molding the first half 200A and second half 200B of the outer sheath around antenna core 205, RTV silicone is most effective in bonding antenna conductor 210 and / or flexible support 215 to silicone rubber outer sheath 200. A non-limiting example of a specific RTV silicone used to bond antenna conductor 210 and / or flexible support 215 to outer sheath 200 is by DOWSILTM Manufactured 3145 RTV.

[0045] In some cases, the second bonding material coated on the metal housing 315 of the connector assembly 230 is a material different from RTV silicone. For example, the second bonding material can be DOWSIL TM 92 - 023, DOWSIL TM 3 - 1598 and / or DOWSIL TM 2 - 4207, which is more effective than RTV silicone in bonding the metal housing 315 to the silicone rubber outer sheath 200. In other cases, RTV silicone is also used to bond the connector assembly 230 to the silicone rubber outer sheath 200. That is, in other cases, before the first half 200A and the second half 200B of the outer sheath 200 are compression molded around the antenna core, the metal housing 315 is coated with the RTV silicone used to coat the antenna conductor 210 and / or the flexible support 215.

[0046] Figure 5 An example is shown in which RTV silicone is dispensed onto a plurality of assembled antenna cores 205. Figure 6 An example is shown of coating the assembled antenna cores 205 with the dispensed RTV silicone via a brush. Although shown as being manually dispensed and spread over the assembled antenna cores 205, it should be understood that other methods for coating the assembled antenna cores 205 with RTV silicone can be used. For example, in some cases, the assembled antenna cores 205 are dipped into the RTV silicone. In some cases, the RTV silicone is sprayed onto the assembled antenna cores 205. In other cases, the RTV silicone is coated onto the assembled antenna cores 205 by a machine.

[0047] After the bonding material is coated on the antenna core 205, the first half 200A and the second half 200B of the silicone rubber outer sheath 200 are compression molded around the antenna core 205. In some cases, a compression force of about 120 kilograms per cubic centimeter (kg / cm 3 ³) is applied to compression mold the first half 200A and the second half 200B of the outer sheath 200 around the antenna core 205. In some cases, a compression force in the range of 100 - 140 kg / cm 3 ³ is applied to compression mold the first half 200A and the second half 200B of the outer sheath 200 around the antenna core 205. In some cases, the first half 200A and the second half 200B of the outer sheath 200 are compression molded around the antenna core 205 at a temperature of about 110 degrees Celsius. In some cases, the first half 200A and the second half 200B of the outer sheath 200 are compression molded around the antenna core 205 at a temperature in the range of 95 to 125 degrees Celsius.

[0048] During compression molding of the first half 200A and the second half 200B of the outer sheath 200 around the antenna core 205, components of the antenna core 205 become bonded to the outer sheath 200 through respective bonding materials. For example, in the case where the antenna conductor 210 and the flexible support 215 are coated with a first bonding material (e.g., RTV silicone), the first bonding material bonds the antenna conductor 210 and the flexible support 215 to the silicone rubber outer sheath 200 during compression molding of the first half 200A and the second half 200B. Similarly, in the case where the connector assembly 230 is coated with a second bonding material different from the first bonding material (e.g., DOWSIL TM 92 - 023, DOWSIL TM 3 - 1598 and / or DOWSIL TM 2 - 4207), during compression molding of the first half 200A and the second half 200B, the second bonding material bonds the connector assembly 230 to the silicone rubber outer sheath 200. In the case where the entire antenna core 205 is coated with the same bonding material (e.g., RTV silicone), during compression molding of the first half 200A and the second half 200B, the bonding material bonds the antenna conductor 210, the flexible support 215, and the connector assembly 230 to the silicone rubber outer sheath 200.

[0049] After compression molding of the first half 200A and the second half 200B of the outer sheath 200 around the antenna core 205, the RTV silicone cures at room temperature (e.g., about 25 degrees Celsius) for 3 to 7 days. In some cases, after compression molding of the first half 200A and the second half 200B of the outer sheath 200 around the antenna core 205, the RTV silicone layer cures at any temperature within the range of 20 to 80 degrees Celsius (in the absence or presence of no humidity during curing). For the case where the connector assembly 230 is coated with a second bonding material different from RTV silicone, the second bonding material can cure in a different amount of time and / or at a different temperature. For example, if DOWSIL TM 92 - 023 is used to bond the connector assembly 230 to the outer sheath 205, DOWSIL TM 92 - 023 can cure at about 60 degrees Celsius for about 30 minutes after compression molding of the first half 200A and the second half 200B of the outer sheath 200 around the antenna core 205. As another example, if DOWSIL TM 3 - 1598 is used to bond the connector assembly 230 to the outer sheath 205, DOWSIL TM3 - 1598 can be cured for about 15 to 180 minutes at about 100 to 150 degrees Celsius (e.g., 180 minutes at 100 degrees Celsius, 30 minutes at 125 degrees Celsius, and / or 15 minutes at 150 degrees Celsius) after compression molding the first half 200A and the second half 200B of the outer sheath 200 around the antenna core 205. As another example, if DOWSIL TM 2 - 4207 is used to bond the connector assembly 230 to the outer sheath 205, then DOWSIL TM 2 - 4207 can be cured for about 3 to 10 minutes at about 50 to 100 degrees Celsius (e.g., 10 minutes at 50 degrees Celsius and 3 minutes at 100 degrees Celsius) after compression molding the first half 200A and the second half 200B of the outer sheath 200 around the antenna core 205.

[0050] After compression molding the first half 200A and the second half 200B onto a single outer sheath 200 surrounding the antenna core 205, the construction of the antenna 105 is completed. Figure 7 A block diagram of the antenna 105 is shown after the outer sheath 200 has been compression molded around the antenna core 205. As shown, a layer 705 of bonding material is disposed between the antenna core 205 and the outer sheath 200. In some cases, the layer 705 of bonding material includes a single bonding material that bonds the antenna core 205 to the outer sheath. In some cases, the layer 705 of bonding material includes a first bonding material layer (e.g., RTV silicone) that bonds a first portion of the antenna core 205 (e.g., the antenna conductor 210 and the flexible support 215) to the outer sheath 200 and a second bonding material layer that bonds a second portion of the antenna core 205 (e.g., the connector assembly 230) to the outer sheath 200. Figure 8 A block diagram of the antenna 105 is shown in which a first layer 705A of RTV silicone is coated on the antenna conductor 210 and the flexible support 215, and a second layer 705B of a second bonding material is coated on the connector assembly 230.

[0051] In some cases, the outer sheath 200 is not formed by compression molding the first half 200A and the second half 200B around the antenna core 205. For example, in some cases, the outer sheath 200 is a single piece that is fitted onto the antenna core 205, such as by sliding the outer sheath 200 onto the antenna core 205 during the construction of the antenna 105. In such a case, the single - piece outer sheath 200 is still bonded to the antenna core 205 using a bonding material such as RTV silicone. For example, the antenna core 205 can be coated with RTV silicone before the outer sheath 200 is slid onto the antenna core 205 or otherwise fitted onto the antenna core 205 to surround the antenna core 205.

[0052] Compared to existing antenna designs that do not include an underfill layer with an adhesive material disposed between the antenna core and the outer sheath, the antenna 105 described herein is more durable and more resistant to damage caused by physical stress applied to the antenna 105. Additionally, when compared to existing antenna designs that include an outer sheath formed from a rigid material (e.g., a thermoplastic material), the silicone rubber outer sheath 200 of the antenna 105 described herein is more flexible when under load. Thus, due to the materials and methods used to construct the antenna 105 described herein, the antenna 105 is better suited to meet the safety and reliability requirements for portable communication devices and antennas established by the NFPA.

[0053] For example, existing antenna designs typically include a rigid thermoplastic outer sheath that is either injection molded and assembled onto the antenna core or a rigid thermoplastic sheath is molded onto the antenna core. However, existing antennas do not include an underfill layer that bonds the outer sheath to the antenna core. Thus, the antenna core is not bonded to the thermoplastic sheath and an air gap is formed between the thermoplastic sheath and the antenna core. When an air gap exists between the antenna core and the outer sheath, the antenna core is free to move within the thermoplastic sheath and independent of the thermoplastic sheath. For example, the antenna core of an existing antenna design can move freely within the outer sheath during stress tests (e.g., drop tests and tumble tests) required by the NFPA. This movement of the antenna core within the outer sheath during operation of the device can result in damage to one or more components of the antenna core.

[0054] In contrast, the antenna 105 described herein (wherein the antenna core 205 is bonded to the outer sheath 200) passes each stress test required by the NFPA. For example, when the antenna 105 is coupled to the device 100, the antenna 105 passes each of the drop test, tumble test, heat and immersion test, direct flame test, and convection heat test required by the NFPA. The drop test includes repeatedly dropping the device 100 from a height of 3 meters (m) such that the device 100 lands on various sides of the device 100 and / or falls at various angles. Additionally, the drop test is performed at temperatures of -10 degrees Fahrenheit, 70 degrees Fahrenheit, and 160 degrees Fahrenheit. The tumble test includes tumbling the device 100 in a drum that rotates at a rate of 15 revolutions per minute (rpm) for up to 3 hours. Due to the flexibility and strength of the materials used to form and bond the outer sheath 200 and the antenna core 205, the antenna 105 does not break during the drop test or the tumble test. That is, the elastic and heat-resistant properties of the conductive material used to form the antenna conductor 210, the polyamide, liquid silicone rubber, and / or glass-filled nylon used to form the flexible support 215, and the silicone rubber used to form the outer sheath 200 allow the antenna 105 to withstand the physical stress of the drop and tumble tests without breaking.

[0055] The heat and immersion test includes subjecting the device 100 to a temperature of at least 350 degrees Fahrenheit for 15 minutes. The heat and immersion test also includes submerging the device 100 in water at a depth of approximately 22 feet for 15 minutes. The direct flame test includes directly exposing the device 100 to a flame at a temperature between 1500 and 2100 degrees Fahrenheit for at least 10 seconds. The convective heat test includes placing the device 100 in a convective oven heated to 500 degrees Fahrenheit for at least 5 minutes. As described above, the antenna 105 is able to pass each of these heat and / or immersion tests because the materials selected for constructing and bonding the outer sheath 200 and the antenna core 205 are rated to withstand the high temperatures of the NFPA stress test. For example, each of the conductive material used to form the antenna conductor 210, the polyamide, liquid silicone rubber, and / or glass-filled nylon used to form the flexible support 215, and the silicone rubber used to form the outer sheath 200 is rated to withstand being submerged in water and exposed to a temperature of at least 350 degrees Fahrenheit for greater than 15 minutes, being directly exposed to a flame between 1500 and 2100 degrees Fahrenheit for greater than 10 seconds, and being exposed to convective heat at 500 degrees Fahrenheit for at least 5 minutes.

[0056] Additionally, as described above, the silicone rubber material used to form the outer sheath 200 of the antenna 105 produces an antenna that is more flexible than existing antenna designs that include a rigid thermoplastic outer sheath. Figure 9 and Figure 10 are graphs showing the results of corresponding flexibility tests for measuring and comparing the flexibility of the antenna 105, existing antenna designs, and a flexibility performance benchmark.

[0057] Specifically, Figure 9 is a graph 900 showing the results of a first flexibility test for measuring the flexibility of the antenna 105 and existing antenna designs. Regarding Figure 9 the block diagram of the device 100 shown in, the first test includes applying a compressive force to the distal end of the antenna 105 in the direction of the body of the device 100. In other words, the first test includes a "pushing" on the distal end of the antenna 105 in the direction along the longitudinal axis of the antenna 105 and toward the body of the device 100.

[0058] The graph 900 includes a first curve 905, a second curve 910, a third curve 915, and a fourth curve 920. The first curve 905 shows the performance benchmark of the compression elongation of the antenna during the first flexure test. The second curve 910 shows a first exemplary relationship between the amount of compressive force applied to the antenna 105 and the corresponding amount of compression elongation experienced by the antenna 105. As shown by the second curve 910, when a compressive force of approximately 3500 grams force (gf) is applied to the distal end of the antenna 105 in a direction along the longitudinal axis of the antenna 105 and toward the body of the device 100, the antenna 105 is compressed by 12.5 millimeters (mm). The third curve 915 shows a second exemplary relationship between the amount of compressive force applied to the antenna 105 and the corresponding amount of compression elongation experienced by the antenna 105. As shown by the third curve 915, when a compressive force of approximately 2300 grams force (gf) is applied to the distal end of the antenna 105 in a direction along the longitudinal axis of the antenna 105 and toward the body of the device 100, the antenna 105 is compressed by 12.5 millimeters (mm).

[0059] Conversely, as shown by the fourth curve 920, when a compressive force of 3500 gf is applied to the distal end of the existing antenna in a direction along the longitudinal axis of the existing antenna and toward the body of the device to which the existing antenna is connected, the existing antenna is only compressed by approximately 2.2 mm. Further, as shown by the fourth curve 920, when a compressive force of 2300 gf is applied to the distal end of the existing antenna in a direction along the longitudinal axis of the existing antenna and toward the body of the device to which the existing antenna is connected, the existing antenna is only compressed by approximately 1.2 mm. As further shown by the fourth curve 920, a compressive force of approximately 6000 gf is required to compress the existing antenna by 12.5 mm in a direction toward the body of the device to which the existing antenna is connected.

[0060] Therefore, by comparing the second curve 910 and the third curve 915 with the fourth curve 920, it can be determined that the force required to compress the antenna 105 by 12.5 mm is at least 40% less and at most 60% less than the force required to compress the existing antenna by 12.5 mm. In other words, the flexibility of the antenna 105 is at least 40% to 60% higher than that of the existing antenna with respect to compression along the respective longitudinal axes of the antenna 105 and the existing antenna.

[0061] In some cases, when a compressive force of less than 4000 gf is applied to the distal end of antenna 105 in a direction along the longitudinal axis of antenna 105 and towards the body of device 100, antenna 105 is compressed by at least 10 mm in a direction towards the body of device 100 along its longitudinal axis. In some cases, when a compressive force of less than 3600 gf is applied to the distal end of antenna 105 in a direction along the longitudinal axis of antenna 105 and towards the body of device 100, antenna 105 is compressed by at least 10 mm in a direction towards the body of device 100 along its longitudinal axis. In some cases, when a compressive force of less than 2500 gf is applied to the distal end of antenna 105 in a direction along the longitudinal axis of antenna 105 and towards the body of device 100, antenna 105 is compressed by at least 10 mm in a direction towards the body of device 100 along its longitudinal axis. In some cases, when a compressive force between 3500 gf and 4000 gf is applied to the distal end of antenna 105 in a direction along the longitudinal axis of antenna 105 and towards the body of device 100, antenna 105 is compressed by at least 10 mm in a direction towards the body of device 100 along its longitudinal axis. In some cases, when a compressive force between 2300 gf and 4000 gf is applied to the distal end of antenna 105 in a direction along the longitudinal axis of antenna 105 and towards the body of device 100, antenna 105 is compressed by at least 10 mm in a direction towards the body of device 100 along its longitudinal axis.

[0062] Figure 10 is graph 1000 showing the results of a second flexibility test for measuring the flexibility of antenna 105 and an existing antenna design. Regarding Figure 10 the block diagram of device 100 shown in, the second test includes applying a linear force to the distal end of antenna 105 in a direction perpendicular to the longitudinal axis of antenna 105. In other words, the second test includes a "thrust" on the distal end of antenna 105 in a direction perpendicular to the longitudinal axis of antenna 105, thereby displacing the distal end of antenna 105 from the longitudinal axis of antenna 105.

[0063] The curve graph 1000 includes a first curve 1005, a second curve 1010, a third curve 1015, and a fourth curve 1020. The first curve 1005 shows the performance benchmark of the compression extension of the antenna during the second flexibility test. The second curve 1010 shows a first exemplary relationship between the amount of force applied to the distal end of the antenna 105 in a direction perpendicular to the longitudinal axis of the antenna 105 and the corresponding displacement of the distal end of the antenna 105 from the longitudinal axis of the antenna 105. As shown in the second curve 1010, when a force of approximately 80 gf is applied to the distal end of the antenna 105 in a direction perpendicular to the longitudinal axis of the antenna 105, the distal end of the antenna 105 is displaced 25 mm from the longitudinal axis of the antenna 105. The third curve 1015 shows a second exemplary relationship between the amount of force applied to the distal end of the antenna 105 in a direction perpendicular to the longitudinal axis of the antenna 105 and the corresponding displacement of the distal end of the antenna 105 from the longitudinal axis of the antenna 105. As shown in the third curve 1015, when a force of approximately 60 gf is applied to the distal end of the antenna 105 in a direction perpendicular to the longitudinal axis of the antenna 105, the distal end of the antenna 105 is displaced 25 mm from the longitudinal axis of the antenna 105.

[0064] In contrast, as shown in the fourth curve 1020, when a force of 80 gf is applied to the distal end of the existing antenna in a direction perpendicular to the longitudinal axis of the existing antenna, the distal end of the existing antenna is only displaced approximately 12.5 mm from the longitudinal axis of the existing antenna. Further, as shown in the fourth curve 1020, when a force of 60 gf is applied to the distal end of the existing antenna in a direction perpendicular to the longitudinal axis of the existing antenna, the distal end of the existing antenna is only displaced approximately 8 mm from the longitudinal axis of the existing antenna. As further shown in the fourth curve 1020, a compressive force of approximately 150 gf is required to displace the distal end of the existing antenna 25 mm from the longitudinal axis of the existing antenna. Thus, by comparing the second curve 1010 and the third curve 1015 with the fourth curve 1020, it can be determined that the force required to displace the distal end of the antenna 105 25 mm from the longitudinal axis of the antenna 105 is at least 40% less and at most 60% less than the force required to displace the distal end of the existing antenna 25 mm from the longitudinal axis of the existing antenna. In other words, when the antenna 105 is displaced or bent from its longitudinal axis, the flexibility of the antenna 105 is at least 40% to 60% higher than that of the existing antenna.

[0065] In some cases, when a force of less than 100 gf is applied to the distal end of antenna 105 in a direction perpendicular to the longitudinal axis of antenna 105, the distal end of antenna 105 is displaced from the longitudinal axis of antenna 105 by at least 20 mm. In some cases, when a force of less than 70 gf is applied to the distal end of antenna 105 in a direction perpendicular to the longitudinal axis of antenna 105, the distal end of antenna 105 is displaced from the longitudinal axis of antenna 105 by at least 20 mm. In some cases, when a force between 70 gf and 100 gf is applied to the distal end of antenna 105 in a direction perpendicular to the longitudinal axis of antenna 105, the distal end of antenna 105 is displaced from the longitudinal axis of antenna 105 by at least 20 mm. In some cases, when a force between 50 gf and 100 gf is applied to the distal end of antenna 105 in a direction perpendicular to the longitudinal axis of antenna 105, the distal end of antenna 105 is displaced from the longitudinal axis of antenna 105 by at least 20 mm. In some cases, when a force less than 60 gf to 80 gf is applied to the distal end of antenna 105 in a direction perpendicular to the longitudinal axis of antenna 105, the distal end of antenna 105 is displaced from the longitudinal axis of antenna 105 by at least 20 mm.

[0066] Figure 11 A flowchart of an example method 1100 for constructing an antenna (e.g., antenna 105) for a portable communication device (e.g., device 100) is shown. It should be understood that although a particular order of steps is indicated as an example in Figure 11 such timing and ordering of such steps may vary in appropriate circumstances without negating the purpose and advantages of the examples described in detail throughout this disclosure. In the example shown, method 1100 begins by winding antenna conductor 210 around flexible support 215 (block 1105). In some cases, antenna conductor 210 is not wound around flexible support 215 but is coupled to flexible support 215 in a different manner.

[0067] At block 1110, antenna conductor 210 and flexible support 215 are coupled to rigid connector assembly 230 to assemble antenna core 205 (block 1110). After assembling antenna core 205, antenna core 205 is coated with an adhesive material such as RTV silicone (block 1115). At block 1120, the first half 200A and the second half 200B of outer sheath 200 are assembled around antenna core 205 (block 1120). Then, the first half 200A and the second half 200B of outer sheath 200 are compression molded around antenna core 205 (block 1125), and antenna core 205 is bonded to outer sheath 200 by the adhesive material (e.g., RTV silicone) (block 1130).

[0068] In the foregoing specification, specific examples, features, and aspects have been described. However, one of ordinary skill in the art will understand that various modifications and changes can be made without departing from the scope of the invention as set forth in the following claims. Accordingly, the specification and drawings are to be regarded as illustrative rather than restrictive, and all such modifications are intended to be included within the scope of this teaching.

[0069] Any benefits, advantages, solutions, and any elements that may cause any benefit, advantage, or solution to occur or become more apparent should not be construed as critical, required, or essential features or elements of any or all of the claims. The invention is defined only by the appended claims, including any modifications made during the pendency of this application and all equivalents of those claims as issued.

[0070] Furthermore, in this document, relational terms such as first, second, top, and bottom may be used solely to distinguish one entity or action from another entity or action, and do not necessarily require or imply any actual such relationship or order between such entities or actions. The terms "comprises", "comprising", "has", "having", "includes", "including", "contains", "containing", or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises, has, includes, or contains a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element that begins with "comprising a", "having a", "including a", or "containing a" does not, without further limitation, preclude the presence of additional identical elements in the process, method, article, or apparatus that comprises, has, includes, or contains that element. Unless expressly stated otherwise herein, the terms "a" and "an" are defined as one or more. The terms "substantially", "essentially", "about", "approximately", or any other form thereof are defined as being close to what is understood by one of ordinary skill in the art, and in a non-limiting embodiment, the term is defined as within 10%, in another embodiment within 5%, in another embodiment within 1%, and in another embodiment within 0.5%. As used herein, the term "coupled" is defined as connected, but not necessarily directly and not necessarily mechanically. A device or structure that is "configured" in a certain way is configured in at least that way, but may also be configured in ways not listed.

[0071] It should be understood that some embodiments may include one or more general-purpose or special-purpose processors (or "processing devices"), such as microprocessors, digital signal processors, custom processors, and field programmable gate arrays (FPGAs), as well as uniquely stored program instructions (including both software and firmware), which control one or more processors to implement some, most, or all of the functions of the methods and / or apparatuses described herein in conjunction with certain non-processor circuits. Alternatively, some or all of the functions may be implemented by a state machine without stored program instructions or in one or more application specific integrated circuits (ASICs), where each function or some combination of certain functions is implemented as custom logic. Of course, a combination of the two methods may be used.

[0072] In addition, embodiments may be implemented as a computer-readable storage medium having computer-readable code stored thereon for programming a computer (e.g., including a processor) to perform the methods as described and claimed herein. Examples of such computer-readable storage media include, but are not limited to, hard disks, CD-ROMs, optical storage devices, magnetic storage devices, ROM (read only memory), PROM (programmable read only memory), EPROM (erasable programmable read only memory), EEPROM (electrically erasable programmable read only memory), and flash memory. Further, it is contemplated that one of ordinary skill in the art, although it may require significant effort and many design choices, such as due to available time, current technology, and economic considerations, will be able to generate such software instructions, programs, and ICs with minimal experimentation under the guidance of the concepts and principles disclosed herein.

[0073] The abstract of the disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It should be understood that it will not be used to interpret or limit the scope or meaning of the claims. Additionally, in the foregoing detailed description, it can be seen that for the purpose of simplifying the disclosure, various features are grouped together in various embodiments. This method of disclosure should not be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, the inventive subject matter lies in less than all of the features of a single disclosed embodiment. Thus, the following claims are incorporated into the detailed description, where each claim stands on its own as a separately claimed subject matter.

Claims

1. An antenna for a portable communication device, the antenna comprising: An antenna core, the antenna core comprising: A conductive antenna element, the conductive antenna element being coupled to a flexible support; and A rigid connector, the rigid connector being coupled to the conductive antenna element and the flexible support; A silicone rubber sheath, the sheath surrounding the antenna core; and A room temperature vulcanizing (RTV) silicone layer, the RTV silicone layer being positioned between the antenna core and the sheath, the RTV silicone layer bonding the antenna core to the sheath.

2. The antenna according to claim 1, wherein The flexible support comprises at least one selected from the group consisting of glass-filled nylon, liquid silicone rubber, and polyamide; And Wherein, the at least one selected from the group consisting of glass-filled nylon, liquid silicone rubber, and polyamide is rated to withstand direct exposure to a temperature between 1500 degrees Fahrenheit and 2100 degrees Fahrenheit for at least 10 seconds.

3. The antenna according to claim 1, wherein, The RTV silicone layer is coated on the conductive antenna element and the flexible support, but not on the rigid connector.

4. The antenna according to claim 1, wherein, The sheath comprises a first half and a second half compression molded around the antenna core and the RTV silicone layer.

5. The antenna according to claim 1, wherein, The conductive antenna element is a helical coil wound around the flexible support.

6. The antenna according to claim 1, wherein, The rigid connector comprises a metal housing; and Wherein, the metal housing is coated with a second bonding material that is not RTV silicone.

7. The antenna according to claim 1, wherein, The silicone rubber sheath is rated to withstand direct exposure to a temperature between 1500 degrees Fahrenheit and 2100 degrees Fahrenheit for at least 10 seconds.

8. The antenna according to claim 1, wherein, When a force of less than 100 grams-force is applied to the distal end of the antenna in a direction perpendicular to the longitudinal axis of the antenna, the distal end of the antenna is displaced at least 20 mm from the longitudinal axis of the antenna.

9. The antenna according to claim 1, wherein, The antenna core further comprises a floating antenna element inserted into the flexible support.

10. A method of constructing an antenna for a portable communication device, the method comprising: Winding a conductive element around a flexible support; Coupling the conductive element and the flexible support to a rigid connector to assemble an antenna core; Coating the antenna core with a room temperature vulcanizing (RTV) silicone layer; Assembling a first half of a silicone rubber sheath and a second half of a silicone rubber sheath around the antenna core; Compression molding the first half of the silicone rubber sheath and the second half of the silicone rubber sheath around the antenna core; And Bonding the silicone rubber sheath to the antenna core through the RTV silicone layer.

11. The method according to claim 10, wherein, The flexible support comprises at least one selected from the group consisting of glass-filled nylon, liquid silicone rubber, and polyamide.

12. The method according to claim 11, wherein, The at least one selected from the group consisting of glass-filled nylon, liquid silicone rubber, and polyamide is rated to withstand direct exposure to temperatures between 1500 degrees Fahrenheit and 2100 degrees Fahrenheit for at least 10 seconds.

13. The method according to claim 10, further comprising: Curing the RTV silicone rubber layer on the antenna core at 25 degrees Celsius for 3 to 7 days.

14. The method according to claim 10, wherein, Compression molding the first half and the second half of the silicone rubber sheath around the antenna core includes: applying a compressive force of 120 kg / cm to the first half and the second half of the silicone rubber sheath at 110 degrees Celsius. 3 of compressive force.

15. The method according to claim 10, wherein, The rigid connector includes a metal housing.

16. The method according to claim 15, further comprising: Coating the metal housing with a second bonding material that is not RTV silicone rubber; And Bonding the silicone rubber sheath to the metal housing by the second bonding material.

17. The method according to claim 10, wherein, Assembling the antenna core further includes: inserting a floating antenna element into the interior of the flexible support.

18. The method according to claim 10, wherein, The silicone rubber sheath is rated to withstand direct exposure to temperatures between 1500 degrees Fahrenheit and 2100 degrees Fahrenheit for at least 10 seconds.

19. The method according to claim 10, wherein, When a force of less than 100 grams-force is applied to the distal end of the antenna in a direction perpendicular to the longitudinal axis of the antenna, the distal end of the antenna is displaced at least 20 mm from the longitudinal axis of the antenna.

20. The method according to claim 10, wherein, Coating the antenna core with the RTV silicone rubber layer includes: coating the conductive element and the flexible support with the RTV silicone rubber layer, but not coating the rigid connector.

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