# US 2013/0154735 A1 · Rf power amplifier and operating method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0154735 A1 - Document ID: US20130154735A1 - Status: Published application - Kind: A1 - Application number: 13/705,328 - Filed: 2012-12-05 - Published: 2013-06-20 - Earliest claimed: 2011-12-20 - Assignees: Renesas Electronics Corporation - Inventors: Masatoshi HASE - Web page: https://patentgrep.com/patent/US20130154735A1 ## CPC - H03F 3/193: with field-effect devices (H03F3/195 takes precedence) - H03F 1/00: Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements - H03F 3/191: Tuned amplifiers (H03F3/193, H03F3/195 take precedence) - H03F 3/24: of transmitter output stages - H03F 3/245: {with semiconductor devices only} - H03F 3/60: Amplifiers in which coupling networks have distributed constants, e.g. with waveguide resonators (H03F3/54 takes precedence) - H03F 3/66: Amplifiers simultaneously generating oscillations of one frequency and amplifying signals of another frequency - H03F 2200/111: the amplifier being a dual or triple band amplifier, e.g. 900 and 1800 MHz, e.g. switched or not switched, simultaneously or not - H03F 2200/204: A hybrid coupler being used at the output of an amplifier circuit - H03F 2200/387: A circuit being added at the output of an amplifier to adapt the output impedance of the amplifier - H03F 2200/451: the amplifier being a radio frequency amplifier - H03F 2200/465: Power sensing - H04B 2001/0408: {with power amplifiers} - H03F: AMPLIFIERS - H04B: TRANSMISSION ## Abstract The present invention reduces the size of a power detection circuit. An RF power amplifier includes an RF amplifier circuit and a power detection circuit. The RF amplifier circuit subjects an RF input signal having a predetermined frequency band to power amplification and generates an RF amplifier output signal. The input terminal of the power detection circuit is coupled to the output of the RF amplifier circuit. The power detection circuit detects a harmonic component having a harmonic frequency that is a whole number multiple of the frequency of a fundamental wave component of the RF amplifier output signal, and generates at an output terminal a detected signal indicative of the signal level of the fundamental wave component of the RF amplifier output signal. The power detection circuit includes an input circuit, which detects the harmonic component, and an output circuit, which generates the detected signal at the output. ## Claims ### Claim 1 An RF power amplifier comprising: an RF amplifier circuit; and a power detection circuit, wherein, when an RF input signal having a predetermined frequency band is supplied to an input terminal of the RF amplifier circuit, the RF amplifier circuit subjects the RF input signal to power amplification and generates an RF amplifier output signal having the predetermined frequency band from an output terminal of the RF amplifier circuit, wherein an input terminal of the power detection circuit is coupled to the output terminal of the RF amplifier circuit, and wherein the power detection circuit detects a harmonic component having a harmonic frequency that is a whole number multiple of the frequency of a fundamental wave component of the RF amplifier output signal, and in accordance with the detected harmonic component, generates at an output terminal a detected signal indicative of the signal level of the fundamental wave component of the RF amplifier output signal. ### Claim 2 (depends on 1) The RF power amplifier according to claim 1, wherein the power detection circuit includes an input circuit, which detects the harmonic component, and an output circuit, which generates the detected signal at the output terminal, and wherein the input circuit also functions as a harmonic termination circuit that is formed by series-coupling a first inductor to a first capacitor, which is coupled between a ground potential and the output terminal of the RF amplifier circuit. ### Claim 3 (depends on 2) The RF power amplifier according to claim 2, wherein the output circuit includes a second inductor, and wherein, when the second inductor is electromagnetically coupled to the first inductor of the input circuit, the output circuit operates so that the detected signal generated by the second inductor due to the electromagnetic coupling is generated at the output terminal of the power detection circuit. ### Claim 4 (depends on 3) The RF power amplifier according to claim 3, wherein the harmonic termination circuit, which is formed by the series-coupling, is included in an output matching circuit coupled to the output terminal of the RF amplifier circuit. ### Claim 5 (depends on 4) The RF power amplifier according to claim 4, wherein the harmonic termination circuit, which is formed by the series-coupling, is coupled between the ground potential and the input or output terminal of the output matching circuit or an intermediate tap between the input and output terminals. ### Claim 6 (depends on 4) The RF power amplifier according to claim 4, wherein one end of the second inductor of the output circuit is coupled to the ground potential through a terminating resistor so that the detected signal is generated from the other end of the second inductor. ### Claim 7 (depends on 4) The RF power amplifier according to claim 4, wherein the output terminal of the output matching circuit can be coupled to a duplexer that provides frequency-division duplex transmission and reception. ### Claim 8 (depends on 4) The RF power amplifier according to claim 4, wherein the predetermined frequency band of the RF input signal has RF frequencies of approximately 700 MHz. ### Claim 9 (depends on 8) The RF power amplifier according to claim 8, wherein the RF frequencies of approximately 700 MHz are the frequencies of LTE band 12, 13, 14, or 17. ### Claim 10 (depends on 9) The RF power amplifier according to claim 9, wherein the RF power amplifier acts as a low-frequency band RF power amplifier in a situation where an RF power amplifier device that provides the transmission of a plurality of frequency bands, such as a high band and a low band, and includes a high-frequency band RF power amplifier, which provides the transmission of the high band, and the low-frequency band RF power amplifier, which provides the transmission of the low band. ### Claim 11 A method of operating an RF power amplifier that includes an RF amplifier circuit and a power detection circuit, the method comprising the steps of: when an RF input signal having a predetermined frequency band is supplied to an input terminal of the RF amplifier circuit, causing the RF amplifier circuit to subject the RF input signal to power amplification and generate an RF amplifier output signal having the predetermined frequency band from an output terminal of the RF amplifier circuit; allowing an input terminal of the power detection circuit to be coupled to the output terminal of the RF amplifier circuit; permitting the power detection circuit to detect a harmonic component having a harmonic frequency that is a whole number multiple of the frequency of a fundamental wave component of the RF amplifier output signal; and in accordance with the detected harmonic component, causing the power detection circuit to generate at an output terminal a detected signal indicative of the signal level of the fundamental wave component of the RF amplifier output signal. ### Claim 12 (depends on 11) The method according to claim 11, wherein the power detection circuit includes an input circuit, which detects the harmonic component, and an output circuit, which generates the detected signal at the output terminal, and wherein the input circuit also functions as a harmonic termination circuit that is formed by series-coupling a first inductor to a first capacitor, which is coupled between a ground potential and the output terminal of the RF amplifier circuit. ### Claim 13 (depends on 12) The method according to claim 12, wherein the output circuit includes a second inductor, and wherein, when the second inductor is electromagnetically coupled to the first inductor of the input circuit, the output circuit operates so that the detected signal generated by the second inductor due to the electromagnetic coupling is generated at the output terminal of the power detection circuit. ### Claim 14 (depends on 13) The method according to claim 13, wherein the harmonic termination circuit, which is formed by the series-coupling, is included in an output matching circuit coupled to the output terminal of the RF amplifier circuit. ### Claim 15 (depends on 14) The method according to claim 14, wherein the harmonic termination circuit, which is formed by the series-coupling, is coupled between the ground potential and the input or output terminal of the output matching circuit or an intermediate tap between the input and output terminals. ### Claim 16 (depends on 14) The method according to claim 14, wherein one end of the second inductor of the output circuit is coupled to the ground potential through a terminating resistor so that the detected signal is generated from the other end of the second inductor. ### Claim 17 (depends on 14) The method according to claim 14, wherein the output terminal of the output matching circuit can be coupled to a duplexer that provides frequency-division duplex transmission and reception. ### Claim 18 (depends on 14) The method according to claim 14, wherein the predetermined frequency band of the RF input signal has RF frequencies of approximately 700 MHz. ### Claim 19 (depends on 18) The method according to claim 18, wherein the RF frequencies of approximately 700 MHz are the frequencies of LTE band 12, 13, 14, or 17. ### Claim 20 (depends on 19) The method according to claim 19, wherein the RF power amplifier acts as a low-frequency band RF power amplifier in a situation where an RF power amplifier device that provides the transmission of a plurality of frequency bands, such as a high band and a low band, and includes a high-frequency band RF power amplifier, which provides the transmission of the high band, and the low-frequency band RF power amplifier, which provides the transmission of the low band.