RF amplifier and EMI shielded duplexer

Abstract

An RF element with an integrated EMI shield may be used in an RF amplifier. The RF element includes an element housing made of a dielectric material, an RF element circuit, and an EMI shield integral with the element housing to shield the RF element circuit. The EMI shield may include a shielding portion in the element housing and separated from the RF element circuit by a preset distance, and a catch extending from the shielding portion inside the element housing to an outside of the element housing. The engagement member contacts the amplifier housing to secure the RF element to the amplifier housing and ground the EMI shield to the amplifier housing. One example of an RF element includes a duplexer.

Description

Technical Field

[0001] The present invention relates to an RF component having an EMI shield in a component housing, and more particularly to a duplexer having an EMI shield in a duplexer housing for use in an RF amplifier. Background Art

[0002] RF amplifiers are used to amplify RF (radio frequency) signals in communication systems such as CATV systems that provide downstream (forward) signals to subscriber locations and upstream (reverse) signals from subscriber locations. In a hybrid fiber-coaxial (HFC) network that provides CATV service, for example, optical communications are provided between the headend / hub and the optical nodes via optical fiber, and electrical RF communications are provided between the optical nodes and subscriber locations via coaxial cables. In such HFC networks, RF amplifiers are used after the optical nodes to extend the transmission distance of the RF signals and thus extend the range of the CATV service provided to the subscriber locations.

[0003] As the bandwidth of communication systems continues to increase and RF amplifiers are required to handle higher frequencies (e.g., up to 1.8 GHz), electromagnetic interference (e.g., crosstalk and RF leakage) becomes a greater problem. Providing EMI shielding to components in an RF amplifier is challenging, especially given the limited space within the amplifier housing and on the circuit boards in the RF amplifier. An example of an RF component that may need to be shielded includes a duplexer (also known as a duplex filter) used in an RF amplifier to separate a forward RF signal from a reverse RF signal for amplification in the RF amplifier. Summary of the invention

[0004] According to one aspect of the present invention, an RF amplifier includes an amplifier housing supported by the amplifier housing and coupled to an amplifier circuit of an RF signal path. The amplifier circuit includes at least one RF element for receiving at least one RF signal carried on the RF signal path. The at least one RF element includes an element housing made of a dielectric material, an RF element circuit at least partially disposed in the element housing, and an EMI shield. The EMI shield includes a shielding portion located in the element housing and separated from the RF element circuit. The EMI shield also includes a plurality of snap-fits extending from the shielding portion inside the element housing to the outside of the element housing. These snap-fits contact the amplifier housing to fasten the RF element to the amplifier housing and to ground the EMI shield to the amplifier housing.

[0005] According to another aspect of the present invention, an EMI shielded duplexer includes a housing made of a dielectric material, a duplexer circuit at least partially disposed in the housing, and an EMI shield. The EMI shield includes a shielding portion located in the housing and separated from the duplexer circuit. The EMI shield also includes a plurality of engaging members extending from the shielding portion inside the housing to the outside of the housing. These engaging members are used to contact a housing receiving the duplexer to fasten the duplexer to the housing and to ground the EMI shield to the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] These and other features and advantages will be better understood by reading the following detailed description and accompanying drawings, in which:

[0007] Figure 1 is a top perspective view of an RF component with an integrated EMI shield according to an embodiment of the present invention.

[0008] Figure 2 Tie Figure 1 A bottom perspective view of an RF component with an integrated EMI shield is shown.

[0009] Figure 3 Tie Figure 1 A top view of an RF component with an integrated EMI shield is shown.

[0010] Figure 4 Tie Figure 3 A cross-sectional view of an RF component with an integrated EMI shield taken along line 4-4 in FIG.

[0011] Figure 5 Tie Figure 1 An exploded view of an RF component with an integral EMI shield is shown, depicting the EMI shield separated from the component housing.

[0012] Figure 6 is a perspective view of an RF amplifier that may include RF elements with an integrated EMI shield in accordance with an embodiment of the present invention.

[0013] Figure 7 The system can be used in Figure 6 The RF amplifier in the schematic diagram of the RF amplifier circuit.

[0014] Figure 8 Tie Figure 6 A plan view of the interior of an RF amplifier.

[0015] Fig. 9 Tie Figure 6 A cross-sectional view of the RF amplifier taken along line 9-9 in FIG. 1 shows the amplifier housing and RF components with an integrated EMI shield.

[0016] Fig.10 Tie Fig. 9 A partial enlarged view of the RF component with an integrated EMI shield is shown snapped into the amplifier housing.

[0017] [Description of Reference Numerals]

[0018] 100: RF components

[0019] 110: Shell

[0020] 112: Main body

[0021] 114: Side Wall

[0022] 115: Opening

[0023] 116: Top

[0024] 117: Grip

[0025] 118: Bottom

[0026] 119: Part

[0027] 120: RF component circuit

[0028] 122: Circuit components

[0029] 124: Circuit Board

[0030] 126: Electrical contacts

[0031] 130: EMI shielding

[0032] 132: Shielding part

[0033] 134: snap-fit ​​parts

[0034] 135,136: Partial

[0035] 137: Bend

[0036] 4-4,9-9: Line

[0037] 600,600a,600b: Duplexer

[0038] 602: RF Amplifier

[0039] 610: Shell

[0040] 620: Duplexer Circuit

[0041] 626: Electrical contacts

[0042] 630: EMI shielding

[0043] 634: snap-fit ​​parts

[0044] 640: Shell

[0045] 642,644: Shell part

[0046] 646,646a,646b: Port

[0047] 650: RF Amplifier Circuit

[0048] 651: Amplifier circuit board

[0049] 652,654: Signal

[0050] 656,658: Gain stage

[0051] 660: Chassis

[0052] 662,662a,662b: socket

[0053] 664: Casing wall DETAILED DESCRIPTION

[0054] The RF component with an integrated EMI shield according to the present invention can be used in an RF amplifier. The RF component includes a component housing made of a dielectric material, an RF component circuit, and an EMI shield that is integrated with the component housing to shield the RF component circuit. The EMI shield may include a shielding portion located in the component housing and separated from the RF component circuit by a preset distance and a plurality of snap-fits extending from the inside of the component housing to the outside of the component housing. The snap-fits contact the amplifier housing to fasten the RF component to the amplifier housing and to ground the EMI shield to the amplifier housing. An example of an RF component includes a duplexer.

[0055] RF components with integrated EMI shields can be used in RF amplifiers, such as line extender (LE) amplifiers in hybrid fiber coaxial (HFC) networks that provide CATV services. Such RF amplifiers may be capable of amplifying RF signals up to 1.8 GHz. At those higher frequencies (e.g., above 1.8 GHz), there may be problems with RF crosstalk and leakage in RF components (e.g., duplexers) that receive RF signals. Previous attempts to shield duplexers involved adding additional metal layers on top of the duplexer housing. These separate shields must release screw locks to access the duplexer, and when technicians in the field troubleshoot the amplifier, these separate shields may be lost and / or cannot be properly reinstalled. Providing an integrated EMI shield can provide improved EMI shielding by shorting unnecessary RF signals to ground (e.g., ground shorting to the amplifier housing) while also allowing the EMI shield to be removed as a single unit with the duplexer (or other shielded RF component). One challenge with integrated EMI shields is positioning the EMI shield relative to RF component circuits (eg, duplexer circuits) to short out unwanted RF signals without shorting out desirable RF signals.

[0056] As used herein, the term "coupled" refers to any connection, coupling, connection or similar relationship between multiple elements. Such "coupled" multiple elements do not need to be directly connected to each other and may be separated by intermediate elements.

[0057] Please refer to Figures 1 to 5 , an embodiment of an RF component 100 with an integrated EMI shield is described and illustrated in detail. The RF component 100 may generally include a component housing 110 made of a dielectric material such as plastic, an RF component circuit 120 at least partially disposed in the component housing 110, and an EMI shield 130 that is integral with the component housing 110. In the illustrated embodiment, the component housing 110 includes a body portion 112 having a rectangular shape, a closed top end 116, and an open bottom end 118, wherein the body portion 112 has a side wall 114 defining an opening 115. The component housing 110 may also include a grip portion 117 extending from the closed top end 116 to allow a user to easily grip the RF component 100 for removal and / or insertion. Other shapes and configurations of the component housing are contemplated and fall within the scope of the present invention.

[0058] like Figure 5 As shown in more detail, the EMI shield 130 includes a shielding portion 132 located inside the component housing 110 and a plurality of snap-fit ​​members 134 extending from the shielding portion 132. Figure 4 As shown, the shielding portion 132 is located inside the body portion 112 of the housing 110, and as shown in FIG. Figures 1 to 4As shown, the clips 134 extend to the exterior of the housing 110 through the opening 115 defined by the side walls 114 of the body portion 112. The clips 134 contact the amplifier chassis (not shown) to secure the RF component 100 to the amplifier chassis and to ground the EMI shield to the amplifier chassis, as will be described in more detail below. Although the illustrated embodiment shows two clips 134 extending through each of these side walls 114, any number of clips may be used on any number of side walls as long as the RF component 100 is adequately secured and grounded.

[0059] The shielding portion 132 and the snap-fit ​​member 134 can be formed as a single component from a conductive material such as stainless steel or phosphor bronze that can provide EMI shielding. In the illustrated embodiment, the shielding portion 132 has a substantially flat configuration and shape that conforms to the interior of the body portion 112 of the housing 110. The shielding portion 132 can be as far away from the RF component circuit 120 as possible to prevent the EMI shield 130 from generating a capacitive effect and shorting out useful RF signals. In one example, the shielding portion 132 is separated from the RF component circuit 120 by a distance in the range of approximately 0.625 inches (in) to 1 inch. Figure 4 As shown, the shield portion 132 may abut against the closed top end 116 inside the body portion 112 of the component housing 110 to maximize spacing from the RF component circuitry 120 .

[0060] In the illustrated embodiment, the snap-fit ​​member 134 has a leaf spring configuration including a first portion 135 extending from the shield portion 132 and a second portion 136 bent back to the first portion 135. The second portion 136 has a bend 137 that protrudes and engages with the amplifier housing, which will be described in more detail below. This shape and configuration allows the snap-fit ​​member 134 to be spring-biased against the housing to secure the RF component 100 and provide sufficient electrical contact to ground. Other shapes and configurations of the snap-fit ​​member are contemplated and fall within the scope of the present invention.

[0061] The RF component circuit 120 may include a circuit element 122 located on a circuit board 124 and electrical contacts 126 extending from the circuit element 122 and the circuit board 124 to, for example, electrically connect to an amplifier circuit. In the illustrated embodiment, the circuit board 124 of the RF component circuit 120 is supported at the open end 118 of the component housing 110 such that the circuit element 122 is located inside the body portion 112 of the housing 110 and the electrical contacts 126 (e.g., pins) extend from the open end 118 of the housing 110. Figure 4As shown, the circuit board 124 may be supported by the portion 119 of the housing 110 near the open end 118. The RF component circuit 120 may include a duplexer circuit for separating the forward RF signal and the reverse RF signal in the RF amplifier in the HFC network. Other RF components, circuits and configurations are contemplated and fall within the scope of the present invention.

[0062] Please refer to Figures 6 to 10 , an RF amplifier 602 including a duplex filter or duplexer 600a, 600b with an integrated EMI shield is shown and described in more detail. The RF amplifier 602 generally includes an amplifier housing 640 containing an amplifier circuit 650. Figure 6 As shown, one example of an amplifier housing 640 may include a first housing portion 642 and a second housing portion 644 that are pivotally coupled to allow the housing 640 to be closed to protect the amplifier circuitry and opened for service. The amplifier housing may include a port 646 for connecting to a coaxial cable (not shown) that provides an electrical path for carrying forward RF signals and reverse RF signals.

[0063] like Figure 7 As shown schematically, the RF amplifier circuit 650 within the RF amplifier 602 may be coupled to ports 646a, 646b for receiving a forward RF signal 652 and a reverse RF signal 654 on a coaxial cable downstream and upstream, such as carried in an HFC / CATV network. The first port 646a provides an input for the forward RF signal 652 and an output for the reverse RF signal 654, and the second port 646b provides an input for the reverse RF signal 654 and an output for the forward RF signal 652. The RF amplifier circuit 650 further includes a first duplexer 600a coupled to the port 646a, a second duplexer 600b coupled to the port 646b, and a forward gain stage 656 and a reverse gain stage 658 located between the duplexers 600a and 600b. The duplexers 600a, 600b transmit forward signals (such as Figure 7 F in the figure) and the reverse signal (such as Figure 7 In particular, the first duplexer 600a separates and passes the forward RF signal 652 received at the first port 646 for amplification by the forward gain stage 656, and the second duplexer 600b separates and passes the reverse RF signal 654 received at the second port 648 for amplification by the reverse gain stage 658. The duplexers and gain stages may be implemented using circuit elements known in RF amplifiers.

[0064] like Figure 8As shown, the RF amplifier circuit 650 is located inside the amplifier housing 640 having an amplifier housing 660, such as in one of the plurality of housing portions 642. The amplifier circuit board (not shown) Figure 8 ) is also located in housing portion 642 inside amplifier housing 660, which will be described below. Amplifier housing 660 includes sockets 662a, 662b for accommodating duplexer 600 and other RF components known to be used in RF amplifiers. In the illustrated embodiment, one of the plurality of sockets 662a includes duplexer 600 and one of the plurality of sockets 662b is empty. As shown, RF amplifier circuit 650 may include other RF components, such as plug-in high pass filter / adjustment components, plug-in low pass filter / adjustment components, plug-in frequency equalization modules, or any other plug-in RF components that snap into sockets in the amplifier housing in a similar manner. These other RF components may also include an integrated EMI shield as disclosed herein.

[0065] Fig. 9 as well as Fig.10 A cross-sectional view of an amplifier housing 660 is depicted, including an amplifier circuit board 651 located within the housing 660 and a duplexer 600 located in a socket 662. The duplexer 600 is electrically connected to the amplifier circuit board 651 and engages with a housing wall 664 within the socket 662. As described above, the duplexer 600 includes a housing 610 and an EMI shield 630 having a snap fit 634 extending from the housing 610 to engage with the housing wall 664 within the socket 662. The duplexer 600 includes a duplexer circuit 620 having electrical contacts 626 (e.g., pins) that engage and electrically connect to contact points located on the amplifier circuit board 651. The snap fit 634 thus secures the duplexer 600 in the socket 662 of the housing 660 while also providing an electrical connection to the housing 660 for grounding. The duplexer 600 can be easily removed from the housing 660 without disconnecting the EMI shield and the EMI shield 630 remains integral with the duplexer 600 .

[0066] Therefore, the RF component with an integrated EMI shield according to an embodiment of the present invention improves the EMI shielding effect of the RF component (eg, a duplexer) located in an RF amplifier without requiring a separate EMI shield located on top of and covering the RF component.

[0067] Although the principles of the present invention have been described herein, it should be understood by those skilled in the art that the description is exemplary only and is not intended to limit the scope of the present invention. In addition to the exemplary embodiments shown and described herein, other embodiments are contemplated within the scope of the present invention. Changes and modifications made by those skilled in the art are considered to be within the scope of the present invention.

Claims

1. An RF amplifier, characterized in that: Include: an amplifier housing; an amplifier circuit supported by the amplifier housing and coupled to an RF signal path, wherein the amplifier circuit includes at least one RF element for receiving at least one RF signal carried on the RF signal path, the at least one RF element including: a component housing made of a dielectric material; an RF component circuit at least partially disposed in the component housing; and An EMI shielding component includes a shielding portion located in the component housing and separated from the RF component circuit and a plurality of snap-fit ​​components extending from the shielding portion inside the component housing to the outside of the component housing, wherein the plurality of snap-fit ​​components contact the amplifier housing to fasten the RF component to the amplifier housing and ground the EMI shielding component to the amplifier housing.

2. The RF amplifier according to claim 1, wherein: The RF component includes a duplexer.

3. The RF amplifier according to claim 1, wherein: The RF component includes an RF filter component.

4. The RF amplifier according to claim 1, wherein: It further comprises an amplifier housing, wherein the amplifier housing and the amplifier circuit are located in the amplifier housing.

5. The RF amplifier according to claim 1, wherein: It further includes a first port for receiving a forward RF signal and for outputting a reverse RF signal and a second port for outputting the forward RF signal and for receiving the reverse RF signal, wherein the RF element receives at least one of the forward RF signal and the reverse RF signal.

6. The RF amplifier according to claim 5, characterized in that The amplifier circuit is used to amplify multiple forward RF signals with a frequency up to 1.8 GHz and to amplify multiple reverse RF signals with a frequency up to 600 MHz.

7. The RF amplifier according to claim 1, wherein: The amplifier circuit further includes at least one gain stage for amplifying the at least one RF signal.

8. The RF amplifier according to claim 1, wherein: The shielding portion abuts against a top end of the component housing.

9. The RF amplifier according to claim 1, wherein: The shielding part and the plurality of engaging parts are formed into a single element by a conductive material.

10. The RF amplifier according to claim 9, characterized in that The plurality of engaging members have a leaf spring configuration for biasing the plurality of engaging members toward the amplifier housing.

11. The RF amplifier according to claim 1, wherein: The component housing includes a body portion defining a plurality of openings, wherein the shielding portion is located in an interior of the body portion and a plurality of the engaging members extend through the plurality of the openings.

12. The RF amplifier according to claim 11, wherein: The component housing further includes a gripping portion located at a top end of the body portion for gripping the RF component to remove and insert the RF component.

13. The RF amplifier according to claim 11, wherein: The shielding portion is located inside the body portion and near the top end of the body portion, and wherein the RF circuit is at least partially located inside the body portion and near a bottom end of the body portion.

14. An EMI shielded duplexer, characterized in that: Include: a housing made of a dielectric material; a duplexer circuit at least partially disposed in the housing; and An EMI shielding component includes a shielding portion located in the shell and separated from the duplexer circuit and a plurality of snap-fit ​​components extending from the shielding portion inside the shell to the outside of the shell, wherein the plurality of snap-fit ​​components are used to contact a casing that receives the duplexer to fasten the duplexer to the casing and ground the EMI shielding component to the casing.

15. The duplexer according to claim 14, wherein: The duplexer circuit is coupled to an RF signal path carrying both a forward RF signal and a reverse RF signal and is used to separate the forward RF signal from the reverse RF signal.

16. The duplexer according to claim 15, wherein: The duplexer circuit is used to receive and separate multiple forward RF signals with frequencies up to 1.8 GHz and multiple reverse RF signals with frequencies up to 600 MHz.

17. The duplexer according to claim 14, wherein: The shielding portion abuts against a top end of the shell.

18. The duplexer according to claim 14, wherein: The shielding part and the plurality of engaging parts are formed into a single element by a conductive material.

19. The duplexer according to claim 18, wherein: The plurality of engaging members have a leaf spring configuration for biasing the plurality of engaging members toward the housing.

20. The duplexer according to claim 14, wherein: The shell includes a body portion defining a plurality of openings, wherein the shielding portion is located inside the body portion and a plurality of the engaging members extend through the plurality of the openings.

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