Filter circuit

Information

  • Patent Grant
  • 10790793
  • Patent Number
    10,790,793
  • Date Filed
    Wednesday, March 20, 2019
    5 years ago
  • Date Issued
    Tuesday, September 29, 2020
    4 years ago
Abstract
A filter circuit includes a pass band filter and a multipath interference mitigation leg. The pass band filter is disposed along a signal path between a provider-side port and a user-side port. The pass band filter is configured to pass a provider bandwidth signal received at the provider-side port and block at least a portion of a home network bandwidth signal received at the user-side port. A frequency spectrum of the home network bandwidth signal is distinct from, and higher than, a frequency spectrum of the provider bandwidth signal. The multipath interference mitigation leg is operatively branched to ground from the signal path. The multipath interference mitigation leg is configured to increase a return loss in the home network bandwidth signal.
Description
FIELD

The present invention relates generally to an electronic filter assembly for use in the cable television (CATV) industry, and more specifically to a circuit assembly that mitigates home data network signals from reflecting within a user's network.


BACKGROUND

In many data distribution networks, electrical signals conveying information propagate along transmission lines across distances and through splitting devices. For example, in a cable television (CATV) network, media content propagates downstream from a head-end facility toward media devices located in various facilities such as homes and businesses. Along the way, the electrical signals conveying the media content propagate along main trunks, through taps, and along multiple branches that ultimately distribute the content to drop cables at respective facilities. The drop cable, which may be a single coaxial cable, typically is connected to a splitting device having two or more outlet ports. Distribution cables connected to the outlet ports route the signals to various rooms, often extending to one or more media devices. The network of distribution cables, splitters, and distribution points is referred to as a drop system.


A typical data distribution network provides many content selections to a user's media devices within the drop system, such as one or more televisions equipped with set top boxes or cable modems. Content selection propagated on a downstream bandwidth of the CATV system may include broadcast television channels, video on demand services, internet data, home security services, and voice over internet (VOIP) services. The content selections are typically propagated in a discrete frequency range, or channel, that is distinct from the frequency ranges of other content selections. Downstream bandwidth includes frequencies typically ranging from 50-1,000 megahertz (MHz).


The typical data distribution network is a two-way communication system. The downstream bandwidth carries signals from the head end to the user and an upstream bandwidth carries upstream signals from the user to the head end. Upstream bandwidth may include data related to video on demand services, such as video requests and billing authorization; internet uploads, such as photo albums or user account information; security monitoring; or other services predicated on signals or data emanating from a subscriber's home. Upstream bandwidth frequencies typically range from 7-49 MHz.


A user data network, or home network, may be coupled to the cable television network via the same coaxial cable delivering the downstream and upstream bandwidth of the CATV system. Often, the user data network is a home entertainment network providing multiple streams of high definition video and entertainment. Examples of home networking technologies include Ethernet, HomePlug, HPNA, and 802.11n. In another example, the user data network may employ technology standards developed by the Multimedia over Coax Alliance (MoCA). The MoCA standards promote networking of personal data utilizing the existing coaxial cable that is already wired throughout the user premises. MoCA technology provides the backbone for personal data networks of multiple wired and wireless products including voice, data, security, home heating/cooling, and video technologies. In such an arrangement, the cable drop from the cable system operator shares the coaxial line or network connection with MoCA-certified devices such as a broadband router or a set top box. The operators use coaxial wiring already existing within the home or business to interconnect the wired and wireless MoCA devices by directly connecting them to the coaxial jacks throughout the premises. MoCA technology delivers broadband-caliber data rates exceeding 130 Mbps, and supports as many as sixteen end points.


A MoCA-certified device such as the broadband router interconnects other MoCA-certified components located within the premises, for example additional set top boxes, routers and gateways, bridges, optical network terminals, computers, gaming systems, display devices, printers, network-attached storage, and home automation such as furnace settings and lighting control. The home network allows distribution and sharing of data or entertainment content among the MoCA-connected devices. For example, a high definition program recorded on a set top box in the living room may be played back by a second set top box located in a bedroom. And, a high definition movie recorded on a camcorder and stored on a user's personal computer may be accessed and displayed through any of the set top boxes within the premises. The home network may also allow high-definition gaming between rooms.


The home network may utilize an open spectrum bandwidth on the coaxial cable to transmit the personal data content, such as entertainment content. For example, a cable system operator may utilize a bandwidth of frequencies up to 1002 MHz, and a satellite system operator may utilize a bandwidth of frequencies from 1550-2450 MHz. The unused range of frequencies in this example, or open spectrum bandwidth, is 1002-1550 MHz. In another example, the open spectrum bandwidth may be higher than 2450 MHz. In one particular example, the Multimedia over Coax Alliance specifies an open spectrum, or home network bandwidth, of 1125-1525 MHz. A home network utilizing the open spectrum bandwidth does not interfere with any of the bandwidth being utilized by the cable television or satellite services provider.


An exemplary filter designed for use in a MoCA network is installed at the point of entry to a premises to allow MoCA transmissions to propagate throughout the home network while preventing the them from interfering with adjacent subscribers in the CATV network. Thus, the MoCA filter passes signals in the provider bandwidth and attenuates signals in the home network bandwidth. One problem noted with existing MoCA filters attenuating the home network spectrum is multipath interference. Multipath interference, or distortion, is a phenomenon in the physics of waves in which a wave from a transmitter travels to a receiver via two or more paths and, under the right conditions, two or more of the wave components interfere. The interference arises due to the wave components having traveled a different path defined by diffraction and the geometric length. The differing speed results in the wave components arriving at the receiver out of phase with each other. Multipath interference is a common cause of “ghosting” in analog television broadcasts, and is exacerbated m a MoCA network because the MoCA standard requires very high transmission energy (e.g., low power loss in the MoCA bandwidth). This high transmission power results in greater reflections at the ports of devices.


SUMMARY

A filter circuit is disclosed. The filter circuit includes a pass band filter and a multipath interference mitigation leg. The pass band filter is disposed along a signal path between a provider-side port and a user-side port. The pass band filter is configured to pass a provider bandwidth signal received at the provider-side port and block at least a portion of a home network bandwidth signal received at the user-side port. A frequency spectrum of the home network bandwidth signal is distinct from, and higher than, a frequency spectrum of the provider bandwidth signal. The multipath interference mitigation leg is operatively branched to ground from the signal path. The multipath interference mitigation leg is configured to increase a return loss in the home network bandwidth signal.


In another embodiment the filter circuit includes a pass band filter and a multipath interference mitigation leg. The pass band filter is configured to block at least a portion of a home network bandwidth signal received at a user-side port. The multipath interference mitigation leg is configured to be operatively branched to ground and increase a return loss in the home network bandwidth signal. A frequency spectrum of the home network bandwidth signal is distinct from, and higher than, a frequency spectrum of a provider bandwidth signal received at a provider-side port.


A pass band filter for mitigating multipath interference is also disclosed. The pass band filter includes a pass portion, an attenuation portion, and an interference mitigation portion. The pass portion is configured to pass a provider signal received at a provider-side port to a user-side port. The provider signal has a provider bandwidth. The attenuating portion is configured to attenuate a home network signal received at the user-side port. The home network signal has a home network bandwidth. The interference mitigation portion is configured to increase a return loss in the home network bandwidth so as to mitigate multipath interference. The home network bandwidth has a home network frequency spectrum that is distinct from, and higher than, a provider frequency spectrum of the provider bandwidth.


A device for mitigating multipath interference is also disclosed. The device includes a pass portion, an attenuating portion, and an interference mitigation portion. The pass portion is configured to pass a provider signal received at a provider-side port to a user-side port. The provider signal has a provider bandwidth. The attenuating portion is configured to attenuate a home network signal received at the user-side port. The home network signal having a home network bandwidth. The interference mitigation portion is configured to increase a return loss in the home network bandwidth so as to mitigate multipath interference. The home network bandwidth has a home network frequency spectrum that is distinct from, and higher than, a provider frequency spectrum of the provider bandwidth.


A pass band filter is also disclosed. The pass band filter includes means for passing a provider signal having a provider bandwidth received at a provider-side port to a user-side port. The provider signal has a provider bandwidth. The pass band filter also includes means for attenuating a home network signal received at the user-side port. The home network signal having a home network bandwidth. The pass band filter also includes means for increasing a return loss in the home network bandwidth so as to mitigate multipath interference. The home network bandwidth has a home network frequency spectrum that is distinct from, and higher than, a provider frequency spectrum of the provider bandwidth.


A filter circuit having a frequency response is also disclosed. The filter circuit includes a signal path extending from an input to an output. The signal path includes a conductive path and a ground. The filter circuit also includes a pass band filter portion disposed along the signal path between the input and the output. The pass band filter portion is configured to pass a first frequency spectrum in a provider bandwidth and attenuate a second frequency spectrum in a home network bandwidth. The frequency response of the filter circuit is characterized by an insertion loss characteristic between the input and the output being less than 3 decibels (dB) in the provider bandwidth and more than 20 dB in the home network bandwidth. The frequency response is further characterized by a return loss characteristic at the output being more than 10 dB in the provider bandwidth and more than 20 dB in the home network bandwidth.


A filter circuit having a frequency response is also disclosed. The filter circuit includes a pass band filter portion configured to pass a first frequency spectrum in a provider bandwidth and attenuate a second frequency spectrum in a home network bandwidth so as to provide the frequency response. The frequency response includes an insertion loss of less than 3 decibels (dB) in the provider bandwidth and more than 20 dB in the home network bandwidth. The frequency response further includes a return loss of more than 10 dB in the provider bandwidth and more than 20 dB in the home network bandwidth.





BRIEF DESCRIPTION OF THE DRAWINGS

For a further understanding of the invention, reference will be made to the following detailed description of the invention which is to be read in connection with the accompanying drawing, wherein:



FIG. 1 schematically illustrates a portion of a home network;



FIG. 2 is a chart showing the insertion lost and input/output loss for a filter circuit within the home network depicted in FIG. 1;



FIG. 3 is a circuit diagram, in schematic form, of one embodiment of a filter in accordance with the present invention



FIG. 4 is a chart showing the insertion loss and input/output return loss for the filter circuit shown in FIG. 3;



FIG. 5 is a circuit diagram, in schematic form, of a second embodiment of a filter in accordance with the present invention; and



FIG. 6 is a chart showing the insertion loss and input/output return loss for the filter circuit shown in FIG. 5.





DETAILED DESCRIPTION

Referring to FIG. 1, a portion of an exemplary home network includes a filter housing 2 located at the point of entry to a premises. In the disclosed embodiment, the filter housing 2 is a standard female f-connector configured to pass a provider bandwidth 4, which may be a CATV system, for example. An exemplary CATV system typically includes a downstream component and an upstream component. The provider bandwidth 4 may propagate a downstream bandwidth in the 50-1,000 MHz range, and also carry an upstream bandwidth in the 7-49 MHz range.


The provider bandwidth 4 passes through a MoCA-enabled splitter 6 having an input port 8 and two distribution ports 10a, 10b respectively. In one example, distribution port 10a is coupled via coaxial cable to a MoCA-enabled device 12 such as a wireless router. Distribution port 10b is coupled to a second MoCA-enabled splitter 14. The second splitter 14 likewise includes an input port 16, a second distribution port 18 connected to a second MoCA-enabled second device 20, such as a set top box, and a third distribution port 22 connected to a third MoCA-enabled third device 24, such as another set top box.


The second splitter 14 is adapted to freely transmit data on a home network bandwidth 26 from any port to any other port. For example, data on the home network bandwidth 26 may be transmitted from the second distribution port 18 to the third distribution port 22. In another example, data may be transmitted in an upstream direction from the first set top box 20 to the second distribution port 18 and through the second input port 16, through the distribution port 10b, then in a downstream direction through distribution port 10a to the wireless router 12. The data may include voice transmission, security, home heating/cooling instructions, and high definition video technologies, for example. The home network bandwidth 26 occupies an open spectrum bandwidth, that is, a frequency range outside the provider bandwidth 4. Referring to the exemplary CATV system above, the home network bandwidth 26 may carry signals in the 1125-1525 MHz range.


In the disclosed embodiment, the filter housing 2 includes internal filter circuitry to secure the home network bandwidth 26 from leaking upstream to other houses on the CATV network, thus protecting the privacy of the home network. One example of the internal filter circuitry, commonly referred to as a point-of-entry or MoCA filter 28, is described in U.S. Pat. No. 8,125,299, entitled “FILTER CIRCUIT”, which is incorporated herein by reference in its entirety.


Two important characteristics which determine the performance of the signals carried by the coaxial device are insertion loss and return loss. Insertion loss refers to the amount of attenuation the signal receives as it passes from the input to the output. Return loss refers to a measure of the reflected energy from the transmitted signal. The loss value is a negative logarithmic number expressed in decibels (dB) however, as used herein, the negative sign is dropped. Thus, a filter circuit initially having a loss characteristic of 1 dB that is improved to 20 dB improves (or decreases) the reflected signal level from about 80% to about 1%. As a rule of thumb, a 3 dB loss reduces power to one half, 10 dB to one tenth, 20 dB to one hundredth, and 30 dB to one thousandth. Therefore, the larger the insertion loss characteristic, the less energy that is lost passing through the circuit. The larger the return loss characteristic, the less energy that is reflected. Multipath return losses can be generated from splitters, coaxial cable, or point-of-entry filters, for example.


Referring to FIG. 2, a frequency response 30 of the exemplary MoCA filter 28 includes an insertion loss 32 between the connector input and the connector output. The insertion loss 32 trace can be interpreted to mean that signals in the provider bandwidth 4 (5 MHz-1002 MHZ) are permitted to pass through the connector, while the signals in the home network bandwidth 26 (1125 MHz-1525 MHz) are attenuated or blocked. The frequency response 30 further includes an input return loss 34 or reflection at the connector input port, and an output return loss 36 or reflection at the connector output port. The return losses 34, 36 are greater than about 20 dB in the pass band, or provider bandwidth 4, but are approximately 1 dB in the stop band, or home network bandwidth 26.


Although the return losses 34, 36 may be adequate in the provider bandwidth 4, very high reflections may be experienced in the home network bandwidth 26. Multipath distortions may be generated from the poor return loss produced from the filters stop band. Referring now back to FIG. 1, a primary transmission path 38 may be defined by data (such as high definition programming) propagating on the home network bandwidth 26 from the first set top box 20 in an upstream direction to the second distribution port 18 on the MoCA-enabled splitter 14, then in a downstream direction through the third distribution port 22 where it is received by the second set top box 24. In this example, data would also propagate from the second distribution port 18 through the second input port 16, through the distribution port 10b, and would be attenuated at the MoCA filter 28 in the filter housing 2. However, because the output return loss 36 is approximately 1 dB within the home network bandwidth 26, almost all the power is reflected and a secondary transmission path 40 sets up for the reflected signal. The data propagating along the secondary transmission path 40 arrives at the receiver (e.g., set top box 24) out of synch with the data in the primary transmission path 38, and multipath interference results.


Referring to FIG. 3 of the drawings, wherein like numerals indicate like elements from FIGS. 1 and 2, one possible topology for an embodiment of an improved filter circuit 142 is provided that reduces the multipath interference experienced with prior MoCA filters. The filter circuit 142 includes a signal path 144 extending from an input 146 to an output 148. In one example, the input 146 is connected to the input port of the filter housing, which may be, in turn, in electrical communication with a supplier-side port such as a tap port (not shown). The output 148 may be adapted to receive signals comprising the provider bandwidth 104, the home network bandwidth 126, noise, and any other signals present on the coaxial cable. Conversely, the input 146 may be connected to the user-side port and the output 148 may be connected to the supplier-side port.


The signal path 144 includes a conductive path 150, such as the center conductor in a coaxial cable, to carry the upstream bandwidth, the downstream bandwidth, and the home network bandwidth. The signal path 144 further includes a ground 152, such as the outer sheath of the coaxial cable that provides a path to ground with various cable connector device.


The filter circuit 142 further includes a pass band filter portion 154 disposed along the signal path 144 between the input 146 and the output 148. The pass band filter portion 154 is configured to pass a first frequency spectrum in the provider bandwidth 104 and attenuate a second frequency spectrum in the home network bandwidth 126. In one embodiment, the pass band filter portion 154 is a hybrid parallel inductor/capacitor (LC) arrangement in which inductors L4 and L5, along with capacitor C8, increase the isolation of the low pass filter. Resonator or tank elements 156a-156c defined by L1/C1, L2/C2, and L3/C3 and capacitive shunts C4, C5, C6, and C7 collectively form an elliptic filter. Other filter designs, such as Butterworth, are equally operable but may require additional components to implement.


The filter circuit 142 further includes a multipath interference mitigation leg 158 operatively branched to ground from the signal path 144. The multipath interference mitigation leg 158 is configured to increase the return loss in the home network bandwidth. In the embodiment shown in FIG. 3, the multipath interference mitigation leg 158 is an absorptive Chebyshev filter circuit that increases the return loss at the output port of the connector without affecting the frequency response of the remaining circuit. The absorptive circuit includes a first lumped element comprising capacitors C9 and C10 in series, with an inductor/capacitor (LC) series connection of L6/C13 shunted to ground at a node between C9 and C10. The absorptive circuit further includes a second lumped element comprising capacitors C10 and C11 in series, with an inductor/capacitor (LC) series connection of L7/C14 shunted to ground at a node between C10 and C11. The absorptive circuit further includes a third lumped element comprising capacitors C11 and C12 in series, with an inductor/capacitor (LC) series connection of L8/C15 shunted to ground at a node between C11 and C12. A termination resistor 160 may be configured to match the impedance of the line load so as to prevent reflections due to impedance mismatch. In the illustrated example, the line load is 75 ohms, and the termination resistor 160 is likewise 75 ohms.



FIG. 4 plots the frequency response 162 of the filter circuit 142 shown in FIG. 3. The insertion loss 132 between the connector input and the connector output is essentially zero in the provider bandwidth 104, and greater than 50 dB in the home network bandwidth 126. Thus, the filter circuit 142 will pass the signals in the provider bandwidth 104 and attenuate the signals in the home network bandwidth 126. The input return loss 134 is essentially unchanged in that the loss of greater than 20 dB in the provider bandwidth 104 will reduce reflections from the input port of the connector. One noted improvement of the filter circuit 142 is that the output return loss 136 of the circuit is improved to greater than 20 dB in both the provider bandwidth 104 and the home network bandwidth 126. In this manner, reflections at the output port are reduced and the strength of the secondary transmission path (described in FIG. 1) will be reduced by as much as 99%. Although a return loss value of more than 20 dB is disclosed, the inventors have discovered that the return loss at the output may be more than 10 dB in the provider bandwidth and home network bandwidth, and the filter circuit of the present invention will still perform adequately.


Referring now to FIG. 5 of the drawings, wherein like numerals indicate like elements from FIGS. 1 and 2, another topology of an improved filter circuit 242 is provided that reduces the multipath interference experienced with prior MoCA filters. The filter circuit 242 includes a signal path 244 extending from an input 246 to an output 248. In one example, the input 246 is connected to the input port of the coaxial cable connector, which may be, in turn, in electrical communication with a supplier-side port such as a tap port (not shown). The output 248 may be adapted to receive signals comprising the provider bandwidth 204, the home network bandwidth 226, noise, and any other signals present on the coaxial cable. Conversely, the input 246 may be connected to the user-side port and the output 248 may be connected to the supplier-side port. Further, the filter circuit 242 may be adapted to filter signals in both directions (e.g., bi-directional), so the physical location of the input 246 and output 248 may be arbitrary.


The signal path 244 includes a conductive path, such as the center conductor in a coaxial cable, to carry the upstream bandwidth, the downstream bandwidth, and the home network bandwidth. The signal path 244 further includes a ground 252, such as the outer sheath of the coaxial cable that provides a path to ground with various cable connector devices.


The filter circuit 242 further includes a pass band filter portion 254 disposed along the signal path 244 between the input 246 and the output 248. The pass band filter portion includes capacitors C1-C9 and inductors L1-L6. The pass band filter portion 254 is configured to pass a first frequency spectrum in the provider bandwidth 204 and attenuate a second frequency spectrum in the home network bandwidth 226. In this manner, the pass band filter portion 254 is a low pass filter. In one embodiment, the pass band filter portion 254 is a parallel inductor/capacitor (LC) arrangement in which inductors L1 and L6 increase the isolation of the low pass filter. Resonator or tank elements 256a-256d defined by L2/C2, L3/C3, L4/C4, and L5/C5 and capacitive shunts C1, C6, C7, C8, and C9 collectively form an elliptic filter. Other filter designs, such as Butterworth, are equally operable but may require additional components to implement.


The filter circuit 242 further includes a multipath interference mitigation leg 258 operatively branched to ground from the signal path 244. The multipath interference mitigation leg 258 includes capacitors C10-C15 and inductors L7 and L8. The multipath interference mitigation leg 258 is configured to increase the return loss in the home network bandwidth. In the embodiment shown in FIG. 5, the multipath interference mitigation leg 258 is an attenuator circuit that increases the return loss at the output port of the connector without affecting the frequency response of the remaining circuit. The attenuator circuit includes a high pass filter portion 264a, 264b and an attenuator portion 266. The high pass filter portions 264a, 264b are Tee-type circuits in one example, but may comprise other types. In the disclosed embodiment, the attenuator portion 266 is a Tee-type resistive attenuator comprising three resistors R1, R2, and R3. However, other arrangements are contemplated, such as a Pi attenuator.



FIG. 6 plots the frequency response 268 of the filter circuit 242 shown in FIG. 5. The insertion loss 232 between the connector input and the connector output is essentially zero in the provider bandwidth 204, and greater than 40 dB in the home network bandwidth 226. Thus, the filter circuit 242 will pass the signals in the provider bandwidth 204 and attenuate the signals in the home network bandwidth 226. The input return loss 234 and output return loss 236 are essentially identical due to the symmetry of the circuit, and comprise a value of greater than 20 dB in both the provider bandwidth 204 and the home network bandwidth 226. In this manner, reflections at the input port and output port are reduced, and the strength of the secondary transmission path (described in FIG. 1) will be reduced by as much as 99%.


One advantage provided by the present invention is that home network multipath distortions at the filter port connections are minimized or even eliminated, thereby enhancing signal quality. Prior art filters designed for the MoCA standard, for example, generated significant multipath distortions from the poor return loss (typically less than 1 dB) produced from the filter's stop band.


Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. For example, although the embodiments disclosed herein comprise analog circuits, the inventors contemplate digital circuitry could be utilized without departing from the scope of the invention. Further, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims
  • 1. A filter circuit, comprising: a pass band filter disposed along a signal path between a provider-side port and a user-side port, wherein the pass band filter is configured to pass a provider bandwidth signal received at the provider-side port and block at least a portion of a home network bandwidth signal received at the user-side port, and wherein a frequency spectrum of the home network bandwidth signal is distinct from, and higher than, a frequency spectrum of the provider bandwidth signal; anda multipath interference mitigation leg operatively branched to ground from the signal path, wherein the multipath interference mitigation leg is configured to increase a return loss in the home network bandwidth signal.
  • 2. The filter circuit of claim 1, wherein the multipath interference mitigation leg comprises an absorptive filter.
  • 3. The filter circuit of claim 2, wherein the absorptive filter increases the return loss at the user-side port without affecting a frequency response of any other component of the filter circuit.
  • 4. The filter circuit of claim 2, wherein the absorptive filter comprises a termination resistor that is configured to substantially match an impedance of a line load of the signal path to prevent reflections due to an impedance mismatch.
  • 5. The filter circuit of claim 1, wherein the multipath interference mitigation leg comprises an attenuator filter.
  • 6. The filter circuit of claim 5, wherein the attenuator filter increases the return loss at the user-side port without affecting a frequency response of any other component of the filter circuit.
  • 7. The filter circuit of claim 5, wherein the attenuator filter comprises: a high-pass filter portion comprising a Tee-type circuit; andan attenuator portion comprising a Tee-type resistive attenuator comprising a plurality of resistors.
  • 8. A filter circuit, comprising: a pass band filter configured to block at least a portion of a home network bandwidth signal received at a user-side port; anda multipath interference mitigation leg configured to be operatively branched to ground and increase a return loss in the home network bandwidth signal,wherein a frequency spectrum of the home network bandwidth signal is distinct from, and higher than, a frequency spectrum of a provider bandwidth signal received at a provider-side port.
  • 9. The filter circuit of claim 8, wherein the pass band filter is positioned in a signal path, and wherein the signal path extends between the provider-side port and the user-side port.
  • 10. The filter circuit of claim 9, wherein the multipath interference mitigation leg is operatively branched to ground from the signal path.
  • 11. The filter circuit of claim 9, wherein the multipath interference mitigation leg comprises an absorptive filter.
  • 12. The filter circuit of claim 11, wherein the absorptive filter increases the return loss at the user-side port without affecting a frequency response of any other component of the filter circuit.
  • 13. The filter circuit of claim 11, wherein the absorptive filter comprises a termination resistor that is configured to substantially match an impedance of a line load of the signal path to prevent reflections due to an impedance mismatch.
  • 14. The filter circuit of claim 8, wherein the multipath interference mitigation leg comprises an attenuator filter.
  • 15. The filter circuit of claim 14, wherein the attenuator filter increases the return loss at the user-side port without affecting a frequency response of any other component of the filter circuit.
  • 16. The filter circuit of claim 14, wherein the attenuator filter comprises a high-pass filter portion and an attenuator portion.
  • 17. A pass band filter for mitigating multipath interference, the pass band filter comprising: a pass portion configured to pass a provider signal received at a provider-side port to a user-side port, the provider signal having a provider bandwidth;an attenuating portion configured to attenuate a home network signal received at the user-side port, the home network signal having a home network bandwidth; andan interference mitigation portion configured to increase a return loss in the home network bandwidth so as to mitigate multipath interference,wherein the home network bandwidth has a home network frequency spectrum that is distinct from, and higher than, a provider frequency spectrum of the provider bandwidth.
  • 18. The pass band filter of claim 17, wherein the pass portion is configured to be disposed along a signal path between the provider-side port and the user-side port.
  • 19. The pass band filter of claim 17, wherein the interference mitigation portion is configured to be operatively branched to ground from a signal path between the provider side port and the user side port.
  • 20. The pass band filter of claim 17, wherein the interference mitigation portion comprises a multipath interference mitigation leg that is configured to be operatively branch to ground from a signal path between the provider-side port and the user-side port.
  • 21. A device for mitigating multipath interference, the device comprising: a pass portion configured to pass a provider signal received at a provider-side port to a user-side port, the provider signal having a provider bandwidth;an attenuating portion configured to attenuate a home network signal received at the user-side port, the home network signal having a home network bandwidth; andan interference mitigation portion configured to increase a return loss in the home network bandwidth so as to mitigate multipath interference,wherein the home network bandwidth has a home network frequency spectrum that is distinct from, and higher than, a provider frequency spectrum of the provider bandwidth.
  • 22. The device of claim 21, wherein the pass portion is configured to be disposed along a signal path between the provider-side port and the user-side port.
  • 23. The device of claim 21, wherein the interference mitigation portion is configured to be operatively branched to ground from a signal path between the provider side port and the user side port.
  • 24. The device of claim 21, wherein the interference mitigation portion comprises a multipath interference mitigation leg that is configured to be operatively branch to ground from a signal path between the provider-side port and the user-side port.
  • 25. A pass band filter, comprising: means for passing a provider signal having a provider bandwidth received at a provider-side port to a user-side port, the provider signal having a provider bandwidth;means for attenuating a home network signal received at the user-side port, the home network signal having a home network bandwidth; andmeans for increasing a return loss in the home network bandwidth so as to mitigate multipath interference,wherein the home network bandwidth has a home network frequency spectrum that is distinct from, and higher than, a provider frequency spectrum of the provider bandwidth.
  • 26. The pass band filter of claim 25, wherein the means for passing is configured to be disposed along a signal path between the provider-side port and the user-side port.
  • 27. The pass band filter of claim 25, wherein the means for increasing is configured to be operatively branched to ground from a signal path between the provider-side port and the user-side port.
  • 28. The pass band filter of claim 25, wherein the means for increasing comprises an interference mitigation portion that is configured to be operatively branched to ground from a signal path between the provider-side port and the user-side port.
  • 29. The pass band filter of claim 28, wherein the interference mitigation portion comprises a multipath interference mitigation leg that is configured to be operatively branched to the ground from the signal path between the provider-side port and the user-side port.
  • 30. A filter circuit having a frequency response, the filter circuit comprising: a signal path extending from an input to an output, the signal path comprising a conductive path and a ground; anda pass band filter portion disposed along the signal path between the input and the output, the pass band filter portion configured to pass a first frequency spectrum in a provider bandwidth and attenuate a second frequency spectrum in a home network bandwidth, wherein the second frequency spectrum is distinct from, and higher than the first frequency spectrum; andwherein the frequency response of the filter circuit is characterized by an insertion loss characteristic between the input and the output being less than 3 decibels (dB) in the provider bandwidth and more than 20 dB in the home network bandwidth, the frequency response further characterized by a return loss characteristic at the output being more than 10 dB in the provider bandwidth and more than 20 dB in the home network bandwidth.
  • 31. The filter circuit of claim 30, wherein the pass band filter portion comprises a hybrid parallel inductor/capacitor arrangement having tank elements and isolation inductors.
  • 32. The filter circuit of claim 30, further comprising a multipath interference mitigation leg configured to be operatively branched from the signal path so as to decrease multipath distortions by improving a return loss characteristic of the home network bandwidth.
  • 33. The filter circuit of claim 30, wherein the second frequency spectrum comprises a Multimedia over Coax Alliance (MoCA) spectrum.
  • 34. The filter circuit of claim 30, wherein the second frequency spectrum is from about 1002 MHz to about 1550 MHz, greater than about 2450 MHz, or both.
  • 35. The filter circuit of claim 30, wherein the second frequency spectrum is from about 1125 MHz to about 1525 MHz.
  • 36. The filter circuit of claim 30, wherein the second frequency spectrum is from about 1125 MHz to about 1675 MHz.
  • 37. A filter circuit having a frequency response, the filter circuit comprising: a pass band filter portion configured to pass a first frequency spectrum in a provider bandwidth and attenuate a second frequency spectrum in a home network bandwidth so as to provide the frequency response, wherein the second frequency spectrum is distinct from, and higher than the first frequency spectrum, wherein the frequency response includes an insertion loss of less than 3 decibels (dB) in the provider bandwidth and more than 20 dB in the home network bandwidth, and wherein the frequency response further includes a return loss of more than 10 dB in the provider bandwidth and more than 20 dB in the home network bandwidth.
  • 38. The filter circuit of claim 37, wherein the pass band filter portion comprises a hybrid parallel inductor/capacitor arrangement having tank elements and isolation inductors.
  • 39. The filter circuit of claim 37, further comprising a signal path extending from an input to an output.
  • 40. The filter circuit of claim 39, further comprising a multipath interference mitigation leg configured to be operatively branched from the signal path so as to decrease multipath distortions by improving a return loss characteristic of the home network bandwidth.
  • 41. The filter circuit of claim 39, wherein the pass band filter portion is disposed in the signal path between the input and the output.
  • 42. The filter circuit of claim 41, wherein the insertion loss is between the input and the output and the return loss is at the output.
  • 43. The filter circuit of claim 37, wherein the second frequency spectrum comprises a Multimedia over Coax Alliance (MoCA) spectrum.
  • 44. The filter circuit of claim 37, wherein the second frequency spectrum is from about 1002 MHz to about 1550 MHz, greater than about 2450 MHz, or both.
  • 45. The filter circuit of claim 37, wherein the second frequency spectrum is from about 1125 MHz to about 1525 MHz.
  • 46. The filter circuit of claim 37, wherein the second frequency spectrum is from about 1125 MHz to about 1675 MHz.
CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 15/937,239, filed Mar. 27, 2018, now U.S. Pat. No. 10,284,162, issued May 7, 2019, which is a continuation of U.S. patent application Ser. No. 15/049,805, filed Feb. 22, 2016, now U.S. Pat. No. 9,979,373, issued May 22, 2018, which is a divisional of U.S. patent application Ser. No. 13/918,639, filed Jun. 14, 2013, now U.S. Pat. No. 9,306,530, issued Apr. 5, 2016, which is a continuation of U.S. patent application Ser. No. 12/697,589, filed Feb. 1, 2010, now U.S. Pat. No. 8,487,717, issued Jul. 16, 2013, by Erdogan Akan and Raymond W. Palinkas and entitled “Multipath Mitigation Circuit for Home Network”, which is incorporated entirely herein by reference.

US Referenced Citations (174)
Number Name Date Kind
2260494 Dante Oct 1941 A
2662217 Roberts Dec 1953 A
3790909 LeFevre Feb 1974 A
3939431 Cohlman Feb 1976 A
4003005 Mukherjee et al. Jan 1977 A
4027219 Van Alphen et al. May 1977 A
4306403 Hubbard et al. Dec 1981 A
4344499 Van der Lely et al. Aug 1982 A
4512033 Schrock Apr 1985 A
4520508 Reichert, Jr. May 1985 A
4648123 Schrock Mar 1987 A
4677390 Wagner Jun 1987 A
4715012 Mueller, Jr. Dec 1987 A
4961218 Kiko Oct 1990 A
4982440 Dufresne et al. Jan 1991 A
5010399 Goodman et al. Apr 1991 A
5126686 Tam Jun 1992 A
5126840 Dufresne et al. Jun 1992 A
5214505 Rabowsky et al. May 1993 A
5231660 West, Jr. Jul 1993 A
5245300 Sasaki et al. Sep 1993 A
5369642 Shioka et al. Nov 1994 A
5485630 Lee et al. Jan 1996 A
5548255 Spielman Aug 1996 A
5557319 Gurusami et al. Sep 1996 A
5557510 McIntyre et al. Sep 1996 A
5604528 Edwards et al. Feb 1997 A
5719792 Bush Feb 1998 A
5740044 Ehrenhardt et al. Apr 1998 A
5745836 Williams Apr 1998 A
5745838 Tresness et al. Apr 1998 A
5815794 Williams Sep 1998 A
5839052 Dean et al. Nov 1998 A
5893024 Sanders et al. Apr 1999 A
5937330 Vince et al. Aug 1999 A
5950111 Georger et al. Sep 1999 A
5970053 Schick et al. Oct 1999 A
6012271 Wilkens et al. Jan 2000 A
6014547 Caporizzo et al. Jan 2000 A
6031432 Schreuders Feb 2000 A
6049693 Baran et al. Apr 2000 A
6069960 Mizukami et al. May 2000 A
6094211 Baran et al. Jul 2000 A
6101932 Wilkens Aug 2000 A
6128040 Shinbori et al. Oct 2000 A
6129187 Bellanger et al. Oct 2000 A
6173225 Stelzle et al. Jan 2001 B1
6185432 Vembu Feb 2001 B1
6205138 Nihal et al. Mar 2001 B1
6229375 Koen May 2001 B1
6321384 Eldering Nov 2001 B1
6348837 Ibelings Feb 2002 B1
6348955 Tait Feb 2002 B1
6373349 Gilbert Apr 2002 B2
6377316 Mycynek et al. Apr 2002 B1
6388539 Rice May 2002 B1
6425132 Chappell Jul 2002 B1
6430904 Coers et al. Aug 2002 B1
6495998 Terreault Dec 2002 B1
6498925 Tauchi Dec 2002 B1
6510152 Gerszberg et al. Jan 2003 B1
6546705 Scarlett et al. Apr 2003 B2
6550063 Matsuura Apr 2003 B1
6560778 Hasegawa May 2003 B1
6570928 Shibata May 2003 B1
6587012 Farmer et al. Jul 2003 B1
6622304 Carhart Sep 2003 B1
6640338 Shibata Oct 2003 B1
6678893 Jung Jan 2004 B1
6683513 Shamsaifar et al. Jan 2004 B2
6725462 Kaplan Apr 2004 B1
6728968 Abe et al. Apr 2004 B1
6737935 Shafer May 2004 B1
6757910 Bianu Jun 2004 B1
6758292 Shoemaker Jul 2004 B2
6804828 Shibata Oct 2004 B1
6843044 Clauss Jan 2005 B2
6845232 Darabi Jan 2005 B2
6920614 Schindler et al. Jan 2005 B1
6868552 Masuda et al. Mar 2005 B1
6877166 Roeck et al. Apr 2005 B1
6928175 Bader et al. Aug 2005 B1
6942595 Hrazdera Sep 2005 B2
7003275 Petrovic Feb 2006 B1
7029293 Shapson et al. Apr 2006 B2
7039432 Stater et al. May 2006 B2
7048106 Hou May 2006 B2
7127734 Amit Oct 2006 B1
7162731 Reidhead et al. Jan 2007 B2
7254827 Terreault Aug 2007 B1
7283479 Ljungdahl et al. Oct 2007 B2
7399255 Johnson et al. Jul 2008 B1
7404355 Viaud et al. Jul 2008 B2
7416068 Ray et al. Aug 2008 B2
7454252 El-Sayed Nov 2008 B2
7464526 Coenen Dec 2008 B2
7505819 El-Sayed Mar 2009 B2
7508284 Shafer Mar 2009 B2
7530091 Vaughan May 2009 B2
7592883 Shafer Sep 2009 B2
7675381 Lin Jun 2010 B2
7742777 Strater et al. Jun 2010 B2
7783195 Riggsby Aug 2010 B2
7952451 Beerwerth May 2011 B2
8179814 Shafer et al. May 2012 B2
8487717 Alkan Jul 2013 B2
9306530 Alkan et al. Apr 2016 B2
9979373 Alkan May 2018 B2
20010016950 Matsuura Aug 2001 A1
20020084871 Fallahi Jul 2002 A1
20020141347 Harp et al. Oct 2002 A1
20020144292 Uemura et al. Oct 2002 A1
20020166124 Gurantz et al. Nov 2002 A1
20020174423 Fifield et al. Nov 2002 A1
20030084458 Ljungdahl et al. May 2003 A1
20040147273 Morphy Jul 2004 A1
20040172659 Ljungdahl et al. Sep 2004 A1
20040229561 Cowley et al. Nov 2004 A1
20050034168 Beveridge Feb 2005 A1
20050047051 Marland Mar 2005 A1
20050144649 Bertonis Jun 2005 A1
20050183130 Sadja et al. Aug 2005 A1
20050210977 Yan Sep 2005 A1
20050283815 Brooks et al. Dec 2005 A1
20050289632 Brooks et al. Dec 2005 A1
20060015921 Vaughan Jan 2006 A1
20060041918 Currivan et al. Feb 2006 A9
20060191359 Tarasinski et al. Aug 2006 A1
20060205442 Phillips et al. Sep 2006 A1
20060241838 Mongiardo et al. Oct 2006 A1
20060282871 Yo Dec 2006 A1
20070024393 Forse et al. Feb 2007 A1
20070288981 Mitsuse et al. Dec 2007 A1
20070288982 Donahue Dec 2007 A1
20080001645 Kuroki Jan 2008 A1
20080022344 Riggsby Jan 2008 A1
20080040764 Weinstein et al. Feb 2008 A1
20080120667 Zaltsman May 2008 A1
20080127287 Alkan et al. May 2008 A1
20080157898 Palinkas et al. Jul 2008 A1
20080168518 Hsue et al. Jul 2008 A1
20080247401 Bhal et al. Oct 2008 A1
20080247541 Cholas et al. Oct 2008 A1
20080271094 Kliger et al. Oct 2008 A1
20080313691 Cholas et al. Dec 2008 A1
20090031391 Urbanek Jan 2009 A1
20090047917 Philips et al. Feb 2009 A1
20090047919 Phillips et al. Feb 2009 A1
20090077608 Romerein et al. Mar 2009 A1
20090153263 Lin Jun 2009 A1
20090165070 McMullin et al. Jun 2009 A1
20090180782 Bernard et al. Jul 2009 A1
20090217325 Kliger et al. Aug 2009 A1
20090320086 Rijssemus et al. Dec 2009 A1
20100017842 Wells Jan 2010 A1
20100095344 Newby Apr 2010 A1
20100100918 Egan Apr 2010 A1
20100125877 Wells May 2010 A1
20100146564 Halik Jun 2010 A1
20100162340 Riggsby Jun 2010 A1
20100194489 Kearns et al. Aug 2010 A1
20100225813 Hirono et al. Sep 2010 A1
20110010749 Alkan Jan 2011 A1
20110051014 Wang et al. Mar 2011 A1
20110069740 Cowley et al. Mar 2011 A1
20110072472 Wells Mar 2011 A1
20110181371 Alkan Jul 2011 A1
20110258677 Shafer Oct 2011 A1
20120054805 Shafer Mar 2012 A1
20120054819 Alkan Mar 2012 A1
20120081190 Rijssemus Apr 2012 A1
20120159556 Alkan Jun 2012 A1
20120331501 Shafer Dec 2012 A1
20130081096 Wells et al. Mar 2013 A1
Foreign Referenced Citations (19)
Number Date Country
55-80989 Jun 1980 JP
55-132126 Oct 1980 JP
58-99913 Dec 1981 JP
57-091055 Jun 1982 JP
58-101582 Jun 1983 JP
59026709 Aug 1984 JP
S1-157035 Jul 1986 JP
05-191416 Jul 1993 JP
07-038580 Feb 1995 JP
11-069334 Mar 1999 JP
2001-177580 Jun 2001 JP
2004-080483 Mar 2004 JP
2005-005875 Jan 2005 JP
2007-166109 Jun 2007 JP
2007-166110 Jun 2007 JP
0024124 Apr 2000 WO
0172005 Sep 2001 WO
0233969 Apr 2002 WO
02091676 Nov 2002 WO
Non-Patent Literature Citations (6)
Entry
Coil craft article, “Inductors as RF Chokes”, document 945-2 Revised Apr. 13, 2011 (Year: 2011).
Author Unknown, International Search Report dated May 31, 2011, PCT Application No. PCT/US2010/049568, filed Sep. 21, 2010.
Wells, “Cable Television Entry Adapter”, U.S. Appl. No. 13/245,510, filed Sep. 26, 2011.
Author Unknown, Office Action Summary dated Mar. 6, 2012, U.S. Appl. No. 12/563,719, filed Sep. 21, 2009.
Author Unknown, Office Action Summary dated Jan. 23, 2012, U.S. Appl. No. 12/250,229, filed Oct. 13, 2008.
Author Unknown, Office Action Summary dated Nov. 11, 2011, U.S. Appl. No. 12/255,008, filed Oct. 21, 2008.
Related Publications (1)
Number Date Country
20190222190 A1 Jul 2019 US
Divisions (1)
Number Date Country
Parent 13918639 Jun 2013 US
Child 15049805 US
Continuations (3)
Number Date Country
Parent 15937239 Mar 2018 US
Child 16359335 US
Parent 15049805 Feb 2016 US
Child 15937239 US
Parent 12697589 Feb 2010 US
Child 13918639 US