# US 2019/0173694 A1 · Signal transmitter device, detection circuit, and signal detection method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0173694 A1 - Document ID: US20190173694A1 - Status: Published application - Kind: A1 - Application number: 16/103,193 - Filed: 2018-08-14 - Published: 2019-06-06 - Earliest claimed: 2017-12-06 - Assignees: Realtek Semiconductor Corp. - Applicants: Realtek Semiconductor Corporation - Inventors: Yuan-Shuo Chang - Web page: https://patentgrep.com/patent/US20190173694A1 ## CPC - H04L 25/0228: {with direct estimation from sounding signals} - H04L 25/0222: {Estimation of channel variability, e.g. coherence bandwidth, coherence time, fading frequency} - H04L 27/367: {using predistortion} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A signal transmitter device includes a transmitter and a detection circuit. The transmitter is configured to transmit an output signal based on a first baseband signal and a second baseband signal, in which the first baseband signal and the second baseband signal have a baseband frequency. The detection circuit is configured to perform twice signal modulations according to the output signal to detect a signal component, which has the baseband frequency, of the output signal, in order to control a compensation circuit to correct a channel mismatch of the transmitter. ## Claims ### Claim 1 A signal transmitter device, comprising: a transmitter configured to transmit an output signal based on a first baseband signal and a second baseband signal, wherein the first baseband signal and the second baseband signal have a baseband frequency; and a detection circuit configured to perform twice signal modulations according to the output signal to detect a signal component, which has the baseband frequency, of the output signal, in order to control a compensation circuit to correct a channel mismatch of the transmitter. ### Claim 2 (depends on 1) The signal transmitter device of claim 1, wherein the detection circuit comprises: a first mixer configured to modulate the output signal according to the output signal, in order to generate a first processed signal; a first filter configured to perform a first filtering operation according to the first processed signal, in order to generate a second processed signal; and a second mixer configured to modulate the second processed signal according to the second processed signal, in order to generate a third processed signal. ### Claim 3 (depends on 2) The signal transmitter device of claim 2, wherein the twice signal modulations are twice square operations, the first mixer performs a first square operation of the twice square operations, and the second mixer performs a second square operation of the twice square operations. ### Claim 4 (depends on 2) The signal transmitter device of claim 2, wherein the detection circuit further comprises: a second filter configured to perform a second filtering operation according to the third processed signal, in order to generate a fourth processed signal; an analog-to-digital converter configured to generate a digital signal according to the fourth processed signal; and a power analyzer circuit configured to analyze the digital signal to generate a detection signal for controlling the compensation circuit. ### Claim 5 (depends on 4) The signal transmitter device of claim 4, wherein the first filter is a high-pass filter, and the second filter is a low-pass filter. ### Claim 6 (depends on 4) The signal transmitter device of claim 4, wherein a bandwidth of the analog-to-digital converter is lower than a double of the baseband frequency. ### Claim 7 (depends on 4) The signal transmitter device of claim 4, wherein the detection circuit further comprises: an amplifier configured amplify the fourth processed signal, wherein the analog-to-digital converter is further configured to generate the digital signal according to the amplified fourth processed signal. ### Claim 8 (depends on 7) The signal transmitter device of claim 7, wherein the amplifier is a variable gain amplifier. ### Claim 9 A detection circuit configured to detect an output signal of a transmitter, the detection circuit comprising: a first mixer configured to perform a first square operation according to the output signal, in order to generate a first processed signal; a first filter configured to perform a first filtering operation according to the first processed signal, in order to generate a second processed signal; and a second mixer configured to perform a second square operation according to the second processed signal, in order to generate a third processed signal, wherein the third processed signal is further processed by a compensation circuit, in order to correct a channel mismatch of the transmitter. ### Claim 10 (depends on 9) The detection circuit of claim 9, further comprising: a second filter configured to perform a second filtering operation according to the third processed signal, in order to generate a fourth processed signal; an analog-to-digital converter configured to generate a digital signal according to the fourth processed signal; and a power analyzer circuit configured to analyze the digital signal, in order to generate a detection signal for controlling the compensation circuit. ### Claim 11 (depends on 10) The detection circuit of claim 10, wherein the output signal comprises a signal component having a baseband frequency, and a bandwidth of the analog-to-digital converter is lower than a double of the baseband frequency. ### Claim 12 (depends on 10) The detection circuit of claim 10, further comprising: an amplifier configured amplify the fourth processed signal, wherein the analog-to-digital converter is further configured to generate the digital signal according to the amplified fourth processed signal. ### Claim 13 (depends on 12) The detection circuit of claim 12, wherein the amplifier is a variable gain amplifier. ### Claim 14 (depends on 10) The detection circuit of claim 10, wherein the first filter is a high-pass filter, and the second filter is a low-pass filter. ### Claim 15 A signal detection method, comprising: performing, by a first mixer, a first signal modulation according to an output signal of a transmitter, in order to generate a first processed signal; performing, by a first filter, a first filtering operation according to a first processed signal, in order to generate a second processed signal; and performing, by a second mixer, a second signal modulation according to the second processed signal, in order to generate a third processed signal, wherein the third processed signal is processed by a compensation circuit, in order to correct a channel mismatch of the transmitter. ### Claim 16 (depends on 15) The signal detection method of claim 15, wherein the first filter is a high-pass filter. ### Claim 17 (depends on 15) The signal detection method of claim 15, further comprising: performing, by a second filter, a second filtering operation according to the third processed signal, to generate a fourth processed signal; generating, by an analog-to-digital converter, a digital signal according to the fourth processed signal; and analyzing, by a power analyzer circuit, the digital signal, in order to generate a detection signal for controlling the compensation circuit. ### Claim 18 (depends on 17) The signal detection method of claim 17, further comprising: amplifying, by an amplifier, the fourth processed signal, wherein the analog-to-digital converter is further configured to generate the digital signal according to the amplified fourth processed signal. ### Claim 19 (depends on 17) The signal detection method of claim 17, wherein the output signal comprises a signal component having a baseband frequency, and a bandwidth of the analog-to-digital converter is lower than a double of the baseband frequency. ### Claim 20 (depends on 17) The signal detection method of claim 17, wherein the second filter is a low-pass filter.