# US 9,385,688 B2 · Filter auto-calibration using multi-clock generator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,385,688 B2 - Document ID: US9385688B2 - Status: Granted - Kind: B2 - Application number: 14/304,066 - Filed: 2014-06-13 - Published: 2014-10-02 - Granted: 2016-07-05 - Earliest claimed: 2010-10-22 - Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.; Global Unichip Corporation - Applicants: Taiwan Semiconductor Manufacturing Company, Ltd.; Global Unichip Corp. - Inventors: Feng Wei Kuo; Mei-Show Chen; Chewn-Pu Jou; Ying-Ta Lu; Jia-Liang Chen - Web page: https://patentgrep.com/patent/US9385688B2 ## CPC - H03H 21/0067: {Means or methods for compensation of undesirable effects} - H03D 3/007: {by converting the oscillations into two quadrature related signals (H03D3/245 takes precedence)} - H03L 7/07: using several loops, e.g. for redundant clock signal generation - H03L 7/0816: {the controlled phase shifter and the frequency- or phase-detection arrangement being connected to a common input} - H03L 7/087: using at least two phase detectors or a frequency and phase detector in the loop - H03L 7/193: the frequency divider/counter comprising a commutable pre-divider, e.g. a two modulus divider - H03L 7/1976: {using a phase accumulator for controlling the counter or frequency divider} - H03H 2021/0081: {Details} - H03H 2210/04: Filter calibration method - H03J 2200/08: Calibration of receivers, in particular of a band pass filter - H04B 1/30: for homodyne or synchrodyne receivers (demodulator circuits H03D1/22) - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) - H03D: DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER (masers, lasers H01S; circuits capable of acting both as modulator and demodulator H03C; details applicable to both modulators and frequency-changers H03C; demodulating pulses H03K9/00; transforming types of pulse modulation H03K11/00; coding, decoding or code conversion, in general H03M; repeater stations H04B7/14; demodulators adapted for AC systems of digital information transmission H04L27/00; synchronous demodulators adapted for colour television H04N9/66) - H03L: AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES (generation of oscillations H03B) - H03J: TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS - H04B: TRANSMISSION ## Abstract A filter auto-calibration system comprises a multi-clock module that includes a multi-clock generator configured to generate a first variable frequency signal based on a channel setting, the multi-clock generator comprising a quadrature signal generator configured to generate an in-phase component and a quadrature component of the first variable frequency signal; and a mixer configured to generate an in-phase component and a quadrature component of a quadrature signal from a received signal other than the first variable frequency signal. The system also comprises at least one filter to be calibrated, and an auto-calibration control module coupled to the multi-clock module and the at least one filter, the auto-calibration control module configured to receive the in-phase component and quadrature component of the first variable frequency signal from the multi-clock module, and configured to control calibration of the at least one filter based on the channel setting. ## Claims ### Claim 1 A filter auto-calibration system, comprising: a multi-clock module, including: a multi-clock generator configured to generate a first variable frequency signal based on a channel setting, the multi-clock generator comprising a quadrature signal generator configured to generate an in-phase component and a quadrature component of the first variable frequency signal; and a mixer configured to generate an in-phase component and a quadrature component of a quadrature signal from a received signal other than the first variable frequency signal; at least one filter to be calibrated, wherein the at least one filter is further configured to filter the in-phase and quadrature components of the quadrature signal generated by the mixer; and an auto-calibration control module coupled to the multi-clock module and the at least one filter, the auto-calibration control module configured to receive the in-phase component and quadrature component of the first variable frequency signal from the multi-clock module, and configured to control calibration of the at least one filter based on the channel setting. ### Claim 2 (depends on 1) The filter auto-calibration system of claim 1, wherein the multi-clock module further includes a frequency synthesizer that supplies a second variable frequency signal to the multi-clock generator based on the channel setting. ### Claim 3 (depends on 2) The filter auto-calibration system of claim 2, wherein the frequency synthesizer is a Sigma-Delta (ΣΔ) fractional-N frequency synthesizer. ### Claim 4 (depends on 2) The filter auto-calibration system of claim 2, wherein the frequency synthesizer comprises a multi-modulus divider that is configured to divide an input signal frequency by a number that is controlled by the channel setting. ### Claim 5 (depends on 4) The filter auto-calibration system of claim 4, wherein the multi-modulus divider comprises a plurality of D flip-flops. ### Claim 6 (depends on 4) The filter auto-calibration system of claim 4, wherein the multi-modulus divider is arranged to supply the second variable frequency signal. ### Claim 7 (depends on 1) The filter auto-calibration system of claim 1, wherein the multi-clock generator comprises a multi-module divider and a quadrature signal generator. ### Claim 8 (depends on 7) The filter auto-calibration system of claim 7, wherein the multi-modulus divider comprises a plurality of D flip-flops and the multi-modulus divider is configured to divide an input signal frequency by a number that is controlled by the channel setting. ### Claim 9 (depends on 7) The filter auto-calibration system of claim 7, wherein the quadrature signal generator comprises two divider-by-2s. ### Claim 10 (depends on 7) The filter auto-calibration system of claim 7, wherein the quadrature signal generator comprises one divider-by-4. ### Claim 11 A method for auto-calibrating a filter, comprising: determining a channel setting; generating a first variable frequency signal utilizing a multi-clock generator based on the channel setting; generating an in-phase component and a quadrature component of the first variable frequency signal using a quadrature signal generator; generating an in-phase component and a quadrature component of a quadrature signal from a received signal other than the first variable frequency signal using a mixer; and executing auto-calibration of the filter by an auto-calibration control module coupled to the multi-clock generator, the multi-clock generator configured to supply the in-phase component and quadrature component of the first variable frequency signal to the auto-calibration control module and the filter, wherein the filter is further configured to filter the in-phase and quadrature components of the quadrature signal generated by the mixer. ### Claim 12 (depends on 11) The method of claim 11, further comprising repeating adjusting the channel setting, generating the first variable frequency signal, and executing auto-calibration, if the desired filter bandwidth is not achieved. ### Claim 13 (depends on 11) The method of claim 11, further comprising replacing the channel setting if the channel setting is different from a previous value of the channel setting. ### Claim 14 (depends on 11) The method of claim 11, further comprising controlling a division number of a multi-modulus divider in the multi-clock generator based on the channel setting. ### Claim 15 (depends on 11) The method of claim 11, further comprising the multi-clock generator receiving a second variable frequency signal from a frequency synthesizer. ### Claim 16 (depends on 15) The method of claim 15, further comprising the frequency synthesizer receiving a reference frequency signal from a local oscillator coupled to a crystal. ### Claim 17 (depends on 15) The method of claim 15, wherein the multi-clock generator receives the second variable frequency signal from a multi-modulus divider in the frequency synthesizer. ### Claim 18 (depends on 17) The method of claim 17, further comprising controlling a division number of the multi-modulus divider in the frequency synthesizer based on the channel setting. ### Claim 19 An integrated circuit including a filter auto-calibration system, the filter auto-calibration system comprising: a multi-clock module including a multi-clock generator and a frequency synthesizer, wherein the frequency synthesizer is configured to supply a first variable frequency signal to the multi-clock generator based on a channel setting, the multi-clock generator is configured to generate a second variable frequency signal based on the channel setting, and the multi-clock generator comprises a multi-modulus divider and a quadrature signal generator configured to generate an in-phase component and a quadrature component of the second variable frequency signal; a mixer configured to generate an in-phase component and a quadrature component of a quadrature signal from a received signal other than the first and second variable frequency signals; at least one filter to be calibrated, wherein the at least one filter is further configured to filter the in-phase and quadrature components of the quadrature signal generated by the mixer; and an auto-calibration control module that is configured to control calibration of the at least one filter based on the channel setting. ### Claim 20 (depends on 19) The integrated circuit of claim 19, wherein the multi-modulus divider comprises a plurality of D flip-flops that is configured to divide the first variable frequency signal from the frequency synthesizer by a number that is controlled by the channel setting.