# US 10,374,697 B2 · Distributed duplexer configuration for blocking and linearity > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,697 B2 - Document ID: US10374697B2 - Status: Granted - Kind: B2 - Application number: 14/973,042 - Filed: 2015-12-17 - Published: 2016-11-10 - Granted: 2019-08-06 - Earliest claimed: 2015-05-05 - Assignees: Andrew Wireless Systems GmbH - Applicants: Andrew Wireless Systems GmbH - Inventors: Peter Schmid; Alfons Dussmann; Thomas Kummetz - Web page: https://patentgrep.com/patent/US10374697B2 ## CPC - H04B 7/2606: {Arrangements for base station coverage control, e.g. by using relays in tunnels} - H04B 1/50: using different frequencies for the two directions of communication - H04B 7/155: Ground-based stations (H04B7/204 takes precedence) - H04L 5/14: Two-way operation using the same type of signal, i.e. duplex - H04W 84/047: {using dedicated repeater stations} - H04W 88/085: {Access point devices with remote components} - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A telecommunications system may be configured to improve linearity and blocking. In some aspects, the telecommunications system may include a duplexer for coupling a common port to a receive path and a transmit path. A distributed low-noise amplifier having two or more separate active devices (e.g., amplifiers) may be positioned in the receive path. A filtering element (e.g., a band-pass filter) may be positioned between the two or more separate active devices. A signal may be routed by the duplexer through the distributed low-noise amplifier. The filtering element may attenuate transmit signals in the receive path. ## Claims ### Claim 1 A remote unit, comprising: a duplexer couplable between (i) a common port and (ii) a receive path and a transmit path, the common port couplable to an antenna for transmitting downlink signals and receiving uplink signals, wherein the duplexer has relaxed isolation characteristics for transmitted downlink signals in the receive path, wherein the duplexer allows at least some transmitted downlink signals to traverse the receive path; a first band-pass filter between a first amplifier and a second amplifier, the first amplifier and the second amplifier forming a low-noise amplifier in the receive path; and a second band-pass filter in the receive path, wherein the second amplifier is positioned between the first band-pass filter and the second band-pass filter; wherein the first band-pass filter and the second band-pass filter are configured to pass uplink signals in a frequency range of the receive path. ### Claim 2 (depends on 1) The remote unit of claim 1, wherein the first amplifier is positioned between the duplexer and the band-pass filter in the receive path. ### Claim 3 (depends on 1) The remote unit of claim 1, wherein the first band-pass filter is configured to attenuate a transmitted downlink signal in the receive path, wherein the second band-pass filter is configured to attenuate the transmitted downlink signal in the receive path. ### Claim 4 (depends on 1) The remote unit of claim 1, wherein the transmit path includes a power amplifier. ### Claim 5 (depends on 1) The remote unit of claim 1, wherein the first amplifier is a low-noise stage and the second amplifier is an amplification stage. ### Claim 6 (depends on 1) The remote unit of claim 1, wherein the first amplifier includes a lower gain than a gain of the first amplifier and the second amplifier combined. ### Claim 7 A telecommunications system, comprising: a duplexer couplable between (i) a common port and (ii) a receive path and a transmit path, wherein the duplexer has relaxed isolation characteristics for transmitted downlink signals in the receive path, wherein the duplexer allows at least some transmitted downlink signals to traverse the receive path; a distributed low-noise amplifier having two or more separate active devices in the receive path; and at least one filtering element positioned between the two or more separate active devices, wherein the at least one filtering element includes a first band-pass filter and a second band-pass filter; wherein the two or more separate active devices includes a first amplifier positioned between the duplexer and the first band-pass filter and a second amplifier positioned between the first band-pass filter and the second band-pass filter; wherein the first band-pass filter and the second band-pass filter are configured to pass uplink signals in a frequency range of the receive path. ### Claim 8 (depends on 7) The telecommunications system of claim 7, wherein the two or more separate active devices include at least a first amplifier having a low-noise stage and a second amplifier having an amplification stage. ### Claim 9 (depends on 7) The telecommunications system of claim 7, wherein the at least one filtering element includes at least a band-pass filter positioned between the first amplifier and the second amplifier. ### Claim 10 (depends on 7) The telecommunications system of claim 7, wherein the two or more separate active devices are positioned in the receive path of a remote unit, wherein the common port is couplable to an antenna for transmitting downlink signals and receiving uplink signals. ### Claim 11 (depends on 7) The telecommunications system of claim 7, wherein the two or more separate active devices are positioned in a receive path of a head-end unit. ### Claim 12 (depends on 7) The telecommunications system of claim 7, further including a power amplifier positioned in the transmit path, wherein the two or more separate active devices are positioned in the receive path. ### Claim 13 (depends on 12) The telecommunications system of claim 12, further including an additional filtering element positioned in the transmit path, wherein the power amplifier is positioned between the duplexer and the additional filtering element. ### Claim 14 (depends on 7) The telecommunications system of claim 7, wherein the at least one filtering element is positioned in the receive path to attenuate a transmit signal in the receive path. ### Claim 15 A method, comprising: receiving a signal at a common port coupled to a receive path and a transmit path by a duplexer, wherein the duplexer has relaxed isolation characteristics for transmitted downlink signals in the receive path, wherein the duplexer allows at least some transmitted downlink signals to traverse the receive path; routing the signal through a first amplifier and a second amplifier in the receive path, the first amplifier and the second amplifier together forming a low-noise amplifier; and attenuating a transmit signal in the receive path using a first band-pass filter positioned between the first amplifier and the second amplifier, wherein the first amplifier is positioned between the duplexer and the first band-pass filter in the receive path; and attenuating a transmit signal in the receive path using a second band-pass filter in the receive path, wherein the second amplifier is positioned between the first band-pass filter and a second band-pass filter in the receive path; wherein the first band-pass filter and the second band-pass filter are configured to pass uplink signals in a frequency range of the receive path. ### Claim 16 (depends on 15) The method of claim 15, wherein the first amplifier is a low-noise stage and the second amplifier is an amplification stage, wherein the first amplifier, the second amplifier, the first band-pass filter, and the second band-pass filter are positioned in the receive path to improve linearity and blocking performance in a telecommunications system. ### Claim 17 (depends on 15) The method of claim 15, further including routing the transmit signal through a power amplifier in the transmit path, wherein the transmit signal generates intermodulation products in the receive path. ### Claim 18 (depends on 17) The method of claim 17, wherein the power amplifier is positioned between the duplexer and a third band-pass filter in the transmit path.