# US 8,571,161 B2 · Electronic device for generating a fractional frequency > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,571,161 B2 - Document ID: US8571161B2 - Status: Granted - Kind: B2 - Application number: 13/147,527 - Filed: 2010-02-03 - Published: 2011-11-24 - Granted: 2013-10-29 - Earliest claimed: 2009-02-27 - Assignees: Politechnico di Milano - Applicants: Salvatore Levantino; Carlo Samori; Marco Zanuso - Inventors: Salvatore Levantino; Carlo Samori; Marco Zanuso - Web page: https://patentgrep.com/patent/US8571161B2 ## CPC - H03B 27/00: Generation of oscillations providing a plurality of outputs of the same frequency but differing in phase, other than merely two anti-phase outputs - H03D 13/00: Circuits for comparing the phase or frequency of two mutually-independent oscillations {(measuring phase G01R25/00; phase-discriminators with yes/no output G01R25/005)} - H03L 7/081: provided with an additional controlled phase shifter {(H03L7/0998 takes precedence)} - H03L 7/085: concerning mainly the frequency- or phase-detection arrangement including the filtering or amplification of its output signal (H03L7/10 takes precedence; circuits for comparing the phase or frequency of two mutually-independent oscillations H03D13/00) - H03L 7/0996: {Selecting a signal among the plurality of phase-shifted signals produced by the ring oscillator} - H03L 7/18: using a frequency divider or counter in the loop (H03L7/20, H03L7/22 take precedence) - H03B: GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS (generators adapted for electrophonic musical instruments G10H; masers or lasers H01S; generation of oscillations in plasma H05H) - 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) ## Abstract It is described an electronic device for generating a fractional synthesized frequency. The device comprises a multi-phase controlled oscillator configured to generate, from a control signal, a plurality of signals phase-shifted each other and comprises a phase detector configured to receive a selected signal from the plurality of phase-shifted signals, to receive a reference signal and to measure a difference between a phase of the selected signal and a phase of the reference signal. The electronic device further comprises control means for estimating, from the measured phase difference, a phase error affecting the generation of at least one of the plurality of phase-shifted signals, and for generating a corrected measure of the phase difference taking into account the estimated phase error, the corrected measure being used to provide the control signal. ## Claims ### Claim 1 An electronic device for generating a fractional synthesized frequency, the device comprising: a multi-phase controlled oscillator configured to generate, from a control signal, a plurality of signals phase-shifted each other; a difference phase detector configured to receive a selected signal from the plurality of phase-shifted signals, to receive a reference signal and to measure a difference between a phase of the selected signal and a phase of the reference signal; wherein the device further comprises: an estimation and correction module configured to receive the measured phase difference and estimate a phase error affecting the generation of at least one of the plurality of phase-shifted signals, and configured to generate a corrected measure of the phase difference taking into account the estimated phase error; and a filter configured to receive the corrected measure of the phase difference and to generate therefrom the control signal to be provided to the multi-phase controlled oscillator. ### Claim 2 (depends on 1) An electronic device according to claim 1, wherein the difference phase detector and the estimation and correction module are digital, the estimation and correction module further comprising: a plurality of accumulators for providing a plurality of phase error signals indicating the estimation of the phase error affecting the generation of the at least one of the plurality of phase-shifted signals; a first plurality of adders/subtractors for receiving the measured phase difference and the plurality of estimated phase error signals and for providing a plurality of difference signals calculated by subtracting the plurality of estimated phase error signals from the measured phase difference; a plurality of parallel-to-serial selectors for receiving the plurality of difference signals and for providing a plurality of corrected phase difference signals selected from the plurality of difference signals according to a selection signal; a parallel-to-serial phase selector for receiving the plurality of corrected phase difference signals and for providing the corrected measure of the phase difference selected from the plurality of corrected phase difference signals according to the selection signal. ### Claim 3 (depends on 2) An electronic device according to claim 2, wherein the plurality of accumulators have the following transfer function in the Z-transform domain: 1/(z−1). ### Claim 4 (depends on 3) An electronic device according to claim 3, further including a second plurality of adders/subtractors for receiving the plurality of corrected phase difference signals and the corrected measure of the phase difference divided by the number of the plurality of phase-shifted signals and for providing to the input terminals of the first plurality of adders/subtractors a plurality of signals calculated by subtracting the divided corrected measure of the phase difference from the plurality of corrected phase difference signals. ### Claim 5 (depends on 4) An electronic device according to claim 4, wherein the difference phase detector is a time to digital converter. ### Claim 6 (depends on 5) An electronic device according to claim 5, further comprising a parallel-to-serial phase-selector for generating the selected signal by selecting cyclically at least part of the plurality of phase-shifted signals. ### Claim 7 (depends on 6) An electronic device according to claim 6, the multi-phase controlled oscillator comprising: a controlled oscillator configured to generate a synthesized signal having the fractional synthesized frequency, according to the control signal; a generator, from the synthesized signal, of the plurality of phase-shifted signals. ### Claim 8 (depends on 7) An electronic device according to claim 7, further comprising a frequency divider connected between the parallel-to-serial phase selector and the difference phase detector for receiving the selected signal and providing to the difference phase detector a divided signal having a frequency divided by an integer value respect to the frequency of the selected signal. ### Claim 9 (depends on 8) An electronic device according to claim 8, wherein the multi-phase controlled oscillator is configured to generate the synthesized frequency variable according to a voltage control signal or according to a digital control signal. ### Claim 10 (depends on 9) An electronic device according to claim 9, further including a logic circuit for controlling the selection of the selected signal from the plurality of phase-shifted signals and for generating the selection signal. ### Claim 11 A radio transmitter comprising an electronic device, said electronic device comprising: a multi-phase controlled oscillator configured to generate, from a control signal, a plurality of signals phase-shifted each other; a difference phase detector configured to receive a selected signal from the plurality of phase-shifted signals, to receive a reference signal and to measure a difference between a phase of the selected signal and a phase of the reference signal; wherein the electronic device further comprises: an estimation and correction module configured to receive the measured phase difference and estimate a phase error affecting the generation of at least one of the plurality of phase-shifted signals, and configured to generate a corrected measure of the phase difference taking into account the estimated phase error; and a filter configured to receive the corrected measure of the phase difference and to generate therefrom the control signal to be provided to the multi-phase controlled oscillator. ### Claim 12 (depends on 11) A radio transmitter according to claim 11, wherein the difference phase detector and the estimation and correction module are digital, the estimation and correction module including: a plurality of accumulators for providing a plurality of phase error signals indicating the estimation of the phase error affecting the generation of the at least one of the plurality of phase-shifted signals; a first plurality of adders/subtractors for receiving the measured phase difference and the plurality of estimated phase error signals and for providing a plurality of difference signals calculated by subtracting the plurality of estimated phase error signals from the measured phase difference; a plurality of parallel-to-serial selectors for receiving the plurality of difference signals and for providing a plurality of corrected phase difference signals selected from the plurality of difference signals according to a selection signal; a parallel-to-serial phase selector for receiving the plurality of corrected phase difference signals and for providing the corrected measure of the phase difference selected from the plurality of corrected phase difference signals according to the selection signal. ### Claim 13 (depends on 12) A radio transmitter according to claim 12, wherein the plurality of accumulators have the following transfer function in the Z-transform domain: 1/(z−1). ### Claim 14 (depends on 13) A radio transmitter according to claim 13, wherein the electronic device further includes a second plurality of adders/subtractors for receiving the plurality of corrected phase difference signals and the corrected measure of the phase difference divided by the number of the plurality of phase-shifted signals and for providing to the input terminals of the first plurality of adders/subtractors a plurality of signals calculated by subtracting the divided corrected measure of the phase difference from the plurality of corrected phase difference signals. ### Claim 15 A radio receiver comprising an electronic device, said electronic device comprising: a multi-phase controlled oscillator configured to generate, from a control signal, a plurality of signals phase-shifted each other; a difference phase detector configured to receive a selected signal from the plurality of phase-shifted signals, to receive a reference signal and to measure a difference between a phase of the selected signal and a phase of the reference signal; wherein the electronic device further comprises: an estimation and correction module configured to receive the measured phase difference and estimate a phase error affecting the generation of at least one of the plurality of phase-shifted signals, and configured to generate a corrected measure of the phase difference taking into account the estimated phase error; and a filter configured to receive the corrected measure of the phase difference and to generate therefrom the control signal to be provided to the multi-phase controlled oscillator. ### Claim 16 (depends on 15) A radio receiver according to claim 15, wherein the difference phase detector and the estimation and correction module are digital, the estimation and correction module includes: a plurality of accumulators for providing a plurality of phase error signals indicating the estimation of the phase error affecting the generation of the at least one of the plurality of phase-shifted signals; a first plurality of adders/subtractors for receiving the measured phase difference and the plurality of estimated phase error signals and for providing a plurality of difference signals calculated by subtracting the plurality of estimated phase error signals from the measured phase difference; a plurality of parallel-to-serial selectors for receiving the plurality of difference signals and for providing a plurality of corrected phase difference signals selected from the plurality of difference signals according to a selection signal; a parallel-to-serial phase selector for receiving the plurality of corrected phase difference signals and for providing the corrected measure of the phase difference selected from the plurality of corrected phase difference signals according to the selection signal. ### Claim 17 (depends on 16) A radio receiver according to claim 16, wherein the plurality of accumulators have the following transfer function in the Z-transform domain: 1/(z−1). ### Claim 18 (depends on 17) A radio receiver according to claim 17, wherein the electronic device further includes a second plurality of adders/subtractors for receiving the plurality of corrected phase difference signals and the corrected measure of the phase difference divided by the number of the plurality of phase-shifted signals and for providing to the input terminals of the first plurality of adders/subtractors a plurality of signals calculated by subtracting the divided corrected measure of the phase difference from the plurality of corrected phase difference signals.