# US 2014/0153461 A1 · Envelope Tracker Driven Transmit Beamforming > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0153461 A1 - Document ID: US20140153461A1 - Status: Published application - Kind: A1 - Application number: 13/930,202 - Filed: 2013-06-28 - Published: 2014-06-05 - Earliest claimed: 2012-12-03 - Assignees: Broadcom Corporation - Applicants: Broadcom Corporation - Inventors: Robert Gustav Lorenz; Sriraman Dakshinamurthy - Web page: https://patentgrep.com/patent/US20140153461A1 ## CPC - H04W 52/0245: {according to signal strength} - Y02D 30/70: in wireless communication networks - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract A method and telecommunication device in which the telecommunication device is provided with multiple antennas and power amplifiers to provide a beamformed transmit stage. An envelope tracking circuit helps achieve significant power savings in the power amplifier and can be used to provide the power supply for the multiple power amplifiers. A single envelope tracking power supply may be used to produce the supply voltage to the individual power amplifiers that operate on the transmit signal and its phase shifted variant. Accordingly, the user equipment experiences the benefits of both reduced power consumption using the envelope tracker and beam formed transmission. ## Claims ### Claim 1 A method comprising: in a wireless communication device comprising a receiver, a transmitter, a plurality of power amplifiers coupled to a plurality of antennas and at least one envelope tracking power supply, simultaneously transmitting from two or more power amplifiers of the plurality of power amplifiers, the two or more power amplifiers powered by a common envelope tracking power supply. ### Claim 2 (depends on 1) The method of claim 1 wherein simultaneously transmitting comprises: transmitting from a first power amplifier a first signal; and transmitting from a second power amplifier a second signal, wherein the second signal is shifted in phase relative to the first signal. ### Claim 3 A method comprising: at a telecommunication device, generating a transmit signal; modifying characteristics of the generated transmit signal in at least one signal path of the telecommunication device to produce one or more modified signals; amplifying the generated transmit signal and the one or more modified signals in a plurality of respective power amplifiers for transmission from a plurality of respective antennas; in response to an envelope of the generated transmit signal, in a single envelope tracking power supply, generating a switched power amplifier voltage supply signal; and applying the switched power amplifier voltage supply signal to the respective power amplifiers of the plurality of respective power amplifiers. ### Claim 4 (depends on 3) The method of claim 3 wherein modifying characteristics of the generated transmit signal comprises producing two or more signals which are phase shifted relative to one another so as to be received coherently at an intended receiver. ### Claim 5 (depends on 4) The method of claim 4 wherein producing two or more signals which are phase shifted comprises applying a constant phase shift to the two or more signals over a transmit band of frequencies. ### Claim 6 (depends on 3) The method of claim 3 wherein a ratio of a first envelope of a first amplified transmit signal from a first respective power amplifier to a second envelope of a second amplified transmit signal from a second respective power amplifier is constant over a transmission from the telecommunication device. ### Claim 7 (depends on 3) The method of claim 3 further comprising operating the telecommunication device to receive signals from a remote radio and transmit output signals including the amplified transmit signal in a time division duplexing mode of operation. ### Claim 8 (depends on 7) The method of claim 7 further comprising: estimating a phase difference of signals received from the remote radio at a plurality of antennas of the telecommunication device; and transmitting as the output signals two signals that are shifted in phase relative to one another in response to the estimated phase difference. ### Claim 9 (depends on 7) The method of claim 7 further comprising: receiving a signal from a remote radio; detecting a phase shift message in the received signal; and transmitting as the output signals two signals that are shifted in phase relative to one another using a phase difference communicated by the phase shift message. ### Claim 10 (depends on 7) The method of claim 7 further comprising: determining a receive path phase difference of a plurality of receive paths of the telecommunication device; determining a transmit path phase difference of a plurality of transmit paths of the telecommunication device; and calibrating at least one of the receive path phase difference and the transmit path phase difference. ### Claim 11 (depends on 10) The method of claim 10 further comprising: transmitting as the output signals two signals that are shifted in phase relative to one another using a phase difference determined using the calibration. ### Claim 12 (depends on 10) The method of claim 10 wherein transmitting the two signals comprises: transmitting a first signal and a second signal with the respective power amplifiers of the telecommunication device, the second signal shifted relative to the first signal by the transmit path phase difference or the receive path phase difference. ### Claim 13 (depends on 10) The method of claim 10 wherein transmitting the two signals comprises: transmitting a first signal and a second signal with the respective power amplifiers of the telecommunication device, the second signal shifted relative to the first signal by a difference between the transmit path phase difference and the receive path phase difference. ### Claim 14 (depends on 7) The method of claim 7 further comprising: determining a first phase difference between a receive path and a transmit path of the telecommunication device on a first antenna; determining a second phase difference between a receive path and a transmit path of the telecommunication device on a second antenna; determining a difference between the first phase difference and the second phase difference; using the difference, adjusting phase of at least one of the transmit path on the first antenna and the transmit path on the second antenna. ### Claim 15 A method comprising: at a telecommunication device, transmitting two respective transmitted signals from two respective power amplifiers of the telecommunication device, wherein each respective power amplifier is driven by a respective envelope tracking switching power supply, each respective envelope tracking switching power supply being driven by a common envelope tracking reference signal, the two respective transmitted signals being phase shifted relative to one another so as to be received coherently at an intended receiver. ### Claim 16 (depends on 15) The method of claim 15 wherein the respective envelope tracking switching power supplies are driven by one or more envelope tracking reference signals. ### Claim 17 (depends on 15) The method of claim 15 further comprising: converting a common digital envelope tracking signal to respective envelope tracking reference signals for driving the each respective envelope tracking switching power supply. ### Claim 18 (depends on 15) The method of claim 15 wherein the respective envelope tracking switching power supplies are driven a common envelope tracking reference signal. ### Claim 19 A telecommunication device comprising: a first transmit circuit including a first power amplifier driving a first antenna, wherein the first transmit circuit is operative to transmit a first signal to a remote radio; a second transmit circuit including a second power amplifier driving a second antenna, wherein the second transmit circuit is operative to transmit a second signal to the remote radio; and an envelope tracking circuit including one or more envelope tracking power supplies producing a switched power amplifier voltage supply signal, the switched power amplifier voltage supply signal being provided to the first power amplifier to power the first power amplifier and being provided to the second power amplifier to power the second power amplifier. ### Claim 20 (depends on 19) The telecommunication device of claim 19 wherein the telecommunication device further comprises: a calibration generator operative to determine a phase difference between the first transmit circuit and the second transmit circuit and determine a constant phase difference to be maintained between the first signal and the second signal to ensure coherent reception of the first signal and the second signal at the remote radio. ### Claim 21 (depends on 19) The telecommunication device of claim 19 wherein a ratio of a first envelope of the first signal to a second envelope of the second signal is substantially constant over a transmission from the telecommunication device.