# US 2023/0412201 A1 · Transmitter and related gain control method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0412201 A1 - Document ID: US20230412201A1 - Status: Published application - Kind: A1 - Application number: 18/318,450 - Filed: 2023-05-16 - Published: 2023-12-21 - Earliest claimed: 2022-06-15 - Assignees: Realtek Semiconductor Corp. - Applicants: Realtek Semiconductor Corporation - Inventors: CHIEN-I CHOU - Web page: https://patentgrep.com/patent/US20230412201A1 ## CPC - H04B 1/0483: {Transmitters with multiple parallel paths} - H03F 1/0222: {by using a signal derived from the input signal} - H03F 1/52: Circuit arrangements for protecting such amplifiers {(monitoring arrangements G01R31/28; increasing reliability in communication systems, e.g. using redundancy H04B1/74)} - H03F 3/195: in integrated circuits - H03F 3/245: {with semiconductor devices only} - H03G 3/3042: {in modulators, frequency-changers, transmitters or power amplifiers} - H03F 2200/447: the amplifier being protected to temperature influence - H03F 2200/468: the temperature being sensed - H04B 2001/0416: {having gain or transmission power control} - H04B: TRANSMISSION - H03F: AMPLIFIERS - H03G: CONTROL OF AMPLIFICATION ## Abstract A transmitter includes an analog transmission circuit, a power amplifier, a voltage detector, a comparator, and a control circuit. The analog transmission circuit is configured to provide a first gain to a first analog signal, so as to generate a second analog signal. The power amplifier is configured to provide a second gain to the second analog signal, so as to generate an output signal to an antenna. The voltage detector is configured to detect a voltage level of the second analog signal. The comparator is configured to generate an indication signal according to the voltage level and a reference level. The control circuit is configured to adjust the first gain of the analog transmission circuit according to the indication signal. ## Claims ### Claim 1 A transmitter, comprising: an analog transmission circuit, configured to provide a first gain to a first analog signal so as to generate a second analog signal; a power amplifier, configured to generate an output signal to an antenna according to the second analog signal; a voltage detector, configured to detect a voltage level of the second analog signal; a comparator, configured to generate an indication signal according to the voltage level and a reference level; and a control circuit, configured to adjust the first gain of the analog transmission circuit according to the indication signal. ### Claim 2 (depends on 1) The transmitter of claim 1, wherein when the voltage level is greater than the reference level, the indication signal has a first level, configured to indicate the control circuit to decrease the first gain. ### Claim 3 (depends on 1) The transmitter of claim 1, further comprising: a power detector, configured to detect a power of the output signal, wherein the control circuit is further configured to adjust the first gain according to the power and the indication signal. ### Claim 4 (depends on 3) The transmitter of claim 3, wherein when the power is not greater than a threshold power, and the voltage level is not greater than the reference level, the indication signal has a second level, configured to indicate the control circuit to increase the first gain. ### Claim 5 (depends on 1) The transmitter of claim 1, further comprising: a heat sensor, configured to detect a temperature of the transmitter, wherein the control circuit is further configured to adjust the first gain according to the temperature. ### Claim 6 (depends on 1) The transmitter of claim 1, wherein the control circuit is further configured to adjust the first gain according to a modulation method of the output signal. ### Claim 7 (depends on 6) The transmitter of claim 6, wherein the power amplifier is configured to provide a second gain to the second analog signal so as to generate the output signal, wherein the control circuit is further configured to adjust the second gain according to the indication signal. ### Claim 8 A gain control method, configured to control a first gain of an analog transmission circuit and a second gain of a power amplifier in a transmitter, wherein the analog transmission circuit provides the first gain to a first analog signal so as to generate a second analog signal, and the power amplifier provides the second gain to the second analog signal so as to generate an output signal, the gain control method comprising: adjusting the first gain and the second gain according to a voltage level of the second analog signal, a power of the output signal and a temperature of the transmitter, comprising: generating an indication signal according to the voltage level and a reference level; and adjusting the first gain according to the indication signal, wherein the output signal is outputted through an antenna of the transmitter. ### Claim 9 (depends on 8) The gain control method of claim 8, wherein the step of adjusting the first gain and the second gain according to the voltage level of the second analog signal, the power of the output signal and the temperature of the transmitter further comprises: detecting the voltage level of the second analog signal; and detecting the power of the output signal. ### Claim 10 (depends on 9) The gain control method of claim 9, wherein the step of adjusting the first gain and the second gain according to the voltage level of the second analog signal, the power of the output signal and the temperature of the transmitter further comprises: detecting the temperature of the transmitter. ### Claim 11 (depends on 10) The gain control method of claim 10, wherein the step of adjusting the first gain according to the indication signal comprises: determining an initial value of a pre-determined power upper limit of the first analog signal; obtaining a peak power of the first analog signal; determining whether to update the initial value of the pre-determined power upper limit according to the indication signal; and adjusting the first gain according to the pre-determined power upper limit, the power and the temperature. ### Claim 12 (depends on 11) The gain control method of claim 11, wherein when the voltage level is greater than the reference level, the indication signal has a first level, and when the voltage level is not greater than the reference level, the indication signal has a second level. ### Claim 13 (depends on 12) The gain control method of claim 12, wherein the step of determining whether to update the pre-determined power upper limit according to the indication signal comprises: determining to update the initial value of the pre-determined power upper limit to be the peak power when the indication signal has the first level; and determining not to update the initial value of the pre-determined power upper limit when the indication signal has the second level. ### Claim 14 (depends on 12) The gain control method of claim 12, wherein the step of adjusting the first gain according to the pre-determined power upper limit, the power and the temperature comprises: when the power is not greater than a threshold power, and the indication signal has the second level, increasing the first gain. ### Claim 15 (depends on 14) The gain control method of claim 14, wherein when the power is not greater than the threshold power, and the indication signal has the second level, the gain control method further comprises: increasing the second gain. ### Claim 16 (depends on 11) The gain control method of claim 11, wherein the step of adjusting the first gain according to the indication signal further comprises: resetting the initial value of the pre-determined power upper limit when a change of the temperature is greater than a pre-determined range. ### Claim 17 (depends on 11) The gain control method of claim 11, wherein in the step of adjusting the first gain according to the pre-determined power upper limit, the power and the temperature, decreasing the first gain when the power is greater than a threshold power. ### Claim 18 (depends on 17) The gain control method of claim 17, wherein when the power is greater than the threshold power, the gain control method further comprises: decreasing the second gain. ### Claim 19 (depends on 17) The gain control method of claim 17, wherein the first gain is decreased by about 7 dB. ### Claim 20 (depends on 8) The gain control method of claim 8, wherein in the step of adjusting the first gain and the second gain according to the voltage level of the second analog signal, the power of the output signal and the temperature of the transmitter, the first gain and the second gain are adjusted further according to a modulation method of the output signal.