# US 2013/0157598 A1 · Systems and Methods for Power Sensing and Antenna Tuning > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0157598 A1 - Document ID: US20130157598A1 - Status: Published application - Kind: A1 - Application number: 13/328,518 - Filed: 2011-12-16 - Published: 2013-06-20 - Earliest claimed: 2011-12-16 - Assignees: Broadcom Corporation - Inventors: Dmitriy ROZENBLIT; Masoud Kahrizi - Web page: https://patentgrep.com/patent/US20130157598A1 ## CPC - H04W 52/52: using AGC [Automatic Gain Control] circuits or amplifiers - H04B 17/101: {for measurement of specific parameters of the transmitter or components thereof} - H04B 17/102: {Power radiated at antenna} - H04B 17/103: {Reflected power, e.g. return loss} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04B: TRANSMISSION ## Abstract Systems and methods are provided for detecting forward power sent to an antenna and reflected power reflected back from the antenna. Embodiments of the present invention provide systems and methods for measuring forward and reflected power and controlling the amount of power supplied to the antenna responsive to these measurements. Embodiments of the present invention enable the power sent to the antenna to be dynamically altered when antenna impendence changes (e.g., when the antenna gets too close to another object). ## Claims ### Claim 1 A power control system for an antenna, the system comprising: a directional coupler coupled to an output of a power amplifier; a first detector coupled to an output of a first port of the directional coupler, wherein the first detector is configured to detect forward power output from the power amplifier and to generate a forward power signal; a first capacitor coupled to an output of a second port of the directional coupler, wherein the first capacitor is configured to pass a reflected power signal representative of power reflected from the antenna; and a power control module coupled to an input of the power amplifier configured to determine an amount of power supplied to the power amplifier based on the forward power signal and the reflected power signal. ### Claim 2 (depends on 1) The power control system of claim 1, wherein a third port of the directional coupler is coupled to an output of the power amplifier, wherein the first port of the directional coupler is configured to output a predefined portion of the power supplied to the third port, and wherein the first detector is configured to detect the forward power by detecting the predefined portion of the power supplied to the third port. ### Claim 3 (depends on 1) The power control system of claim 1, wherein a fourth port of the directional coupler is coupled to an input of the antenna, wherein the second port is coupled to ground, and wherein the reflected power signal received by the first capacitor is caused by power reflected from the antenna to the fourth port. ### Claim 4 (depends on 3) The power control system of claim 3, wherein antenna impedance causes power to be reflected from the antenna to the fourth port. ### Claim 5 (depends on 1) The power control system of claim 1, wherein the first detector is configured to output a low frequency signal as the forward power signal, and wherein the first capacitor is configured to output a high frequency signal as the reflected power signal. ### Claim 6 (depends on 1) The power control system of claim 1, wherein the first detector and the first capacitor output the forward power signal and the reflected power signal over a shared transmission line. ### Claim 7 (depends on 1) The power control system of claim 1, further comprising a multiplexer coupled to the power control module, wherein the multiplexer is configured to pass the forward power signal to the power controller responsive to receiving a control signal indicating that forward power is to be measured. ### Claim 8 (depends on 7) The power control system of claim 7, further comprising an analog to digital converter (ADC) configured to convert the forward power signal into a digital signal before the forward power signal is passed to the power control module. ### Claim 9 (depends on 1) The power control system of claim 1, further comprising: a second capacitor configured to receive the reflected power signal; and a multiplexer coupled to an output of the second capacitor, wherein the multiplexer is configured to pass the reflected power signal to a second detector responsive to receiving a control signal indicating that reflected power is to be measured, and wherein the second detector is configured to send a low frequency reflected power signal to the power control module. ### Claim 10 A system, comprising: a power amplifier module coupled to an antenna, wherein the power amplifier module includes: a power amplifier coupled to a directional coupler, a first detector coupled to a first port of the directional coupler, wherein the first detector is configured to output a forward power signal to a transmission line, and a first capacitor coupled to a second port of the power amplifier, wherein the first capacitor is configured to output a reflected power signal to the transmission line; a transceiver module coupled to the transmission line; and a power control module coupled to the transceiver module, wherein the power control module is configured to alter an amount of power supplied to the power amplifier module based on the forward power signal and the reflected power signal. ### Claim 11 (depends on 10) The system of claim 10, further comprising: a front end module coupled to the antenna, wherein the front end module includes circuitry for multiplexing multiple transmitters and receivers onto the antenna. ### Claim 12 (depends on 10) The system of claim 10, wherein the power control module is further configured to: detect an input impedance of the antenna based on the reflected power signal, and generate a tuning signal for the antenna based on the detected amount of impedance. ### Claim 13 (depends on 10) The system of claim 10, wherein the transceiver module includes: a second detector configured to generate a low frequency reflected power signal; a first multiplexer coupled to power control module, wherein the first multiplexer is configured to: couple the power control module to the transmission line, and couple the power control module to the second detector. ### Claim 14 (depends on 13) The system of claim 13, wherein the transceiver module further includes: a second capacitor coupled to the transmission line; and a second multiplexer coupled to the second detector, wherein the second multiplexer is configured to: couple the second capacitor to the second detector; and couple the power control module to the second detector. ### Claim 15 (depends on 14) The system of claim 14, wherein the power control module is configured to generate a first control signal instructing the first multiplexer to couple the power control module to the transmission line to pass the forward power signal to the power control module. ### Claim 16 (depends on 15) The system of claim 15, wherein the power control module is configured to generate a second control signal instructing the first multiplexer to couple the couple the power control module to the second detector and instructing the second multiplexer to couple the couple the second capacitor to the second detector to pass the low frequency reflected power signal to the power control module. ### Claim 17 (depends on 16) The system of claim 16, wherein the power control module is configured to continuously generate the first control signal and the second control signal to continuously determine forward power and reflected power. ### Claim 18 (depends on 16) The system of claim 16, wherein the power control module is configured to generate a third control signal instructing the second multiplexer to couple the power control module to the second detector to supply power to the power amplifier module. ### Claim 19 A method for controlling power supplied to an antenna, the method comprising: generating a low frequency signal representative of an amount of forward power supplied to the antenna; generating a high frequency signal representative of an amount of reflected power from the antenna; transmitting the low frequency signal and the high frequency signal over a shared transmission line; separating the low frequency signal from the high frequency signal; and determining an amount of power to supply to the antenna based on the low frequency signal and the high frequency signal. ### Claim 20 (depends on 19) The method of claim 19, wherein the low frequency signal is generated by a detector that detects forward power supplied to the antenna, and wherein the high frequency signal is output from a capacitor coupled to the antenna, wherein the capacitor receives power reflected by the antenna and passes high frequencies of the power reflected by the antenna to the shared transmission line.