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CN-122001393-A - Receiver circuit

CN122001393ACN 122001393 ACN122001393 ACN 122001393ACN-122001393-A

Abstract

A wireless receiver circuit includes a terminal for coupling to an antenna and an impedance tuning circuit coupled between the terminal and a receiver path. The impedance tuning circuit is controllable to provide at least two impedance levels. A measurement circuit is coupled to the impedance tuning circuit and configured to measure, for each of the at least two impedance levels, a voltage or current indicative of a signal received by the antenna. The timing circuit includes one or more delay lines, wherein the one or more delay lines are configured to receive an initialization signal from the measurement circuit or the impedance tuning circuit. The timing circuit is configured to provide one or more delay signals to control one or both of the measurement circuit and the impedance tuning circuit to measure the voltage or current at each of the two impedance levels.

Inventors

  • Lucas Zoeshel
  • Slavomil Raphael Malinowski
  • Jacobs Demurmeister
  • FINA THOMAS

Assignees

  • 恩智浦有限公司

Dates

Publication Date
20260508
Application Date
20251105
Priority Date
20241108

Claims (10)

  1. 1. A wireless receiver circuit, comprising: a terminal for coupling to an antenna; An impedance tuning circuit coupled between the terminal and the receiver path, wherein the impedance tuning circuit is controllable to provide at least two impedance levels; A measurement circuit coupled to the impedance tuning circuit and configured to measure, for each of the at least two impedance levels, a voltage or current indicative of a signal received by the antenna, and A timing circuit comprising one or more delay lines, wherein the one or more delay lines are configured to receive an initialization signal from the measurement circuit or the impedance tuning circuit and to provide one or more delay signals to control one or both of the measurement circuit and the impedance tuning circuit to measure the voltage at each of the two impedance levels.
  2. 2. The wireless receiver circuit of claim 1, wherein said controlling one or both of said measurement circuit and said impedance tuning circuit to measure said voltage for each of said two impedance levels comprises: The impedance tuning circuit is configured to receive at least one of the one or more delayed signals to sequentially select one of the at least two impedance levels.
  3. 3. The wireless receiver circuit of claim 1 or claim 2, wherein the controlling one or both of the measurement circuit and the impedance tuning circuit to measure the voltage for each of the two impedance levels comprises the measurement circuit configured to receive at least one of the one or more delay signals to: sampling and holding a first voltage for a first of the at least two impedance levels; Sampling and holding a second voltage for a second of the at least two impedance levels, and The first voltage and the second voltage are compared for determining which of the first and second impedance levels of the at least two impedance levels to select to receive future further signals.
  4. 4. The wireless receiver circuit of any preceding claim, wherein said controlling one or both of said measurement circuit and said impedance tuning circuit to measure said voltage for each of said at least two impedance levels comprises: One of the at least two impedance levels is selected based on which impedance level provides the highest voltage or current measured by the measurement circuit.
  5. 5. The wireless receiver circuit of any preceding claim, wherein, The wireless receiver circuit includes a control circuit including one or more logic gates configured to provide the control to one or both of the measurement circuit and the impedance tuning circuit, and wherein the one or more delay signals are configured to control the one or more logic gates.
  6. 6. The wireless receiver circuit of claim 5, wherein, The wireless receiver circuit includes an envelope detector coupled between the impedance tuning circuit and the measurement circuit, the envelope detector configured to output an envelope voltage indicative of an envelope of the signal received by the antenna, wherein the envelope voltage includes the voltage indicative of the signal received by the antenna.
  7. 7. The wireless receiver circuit of claim 6, wherein the antenna is configured to receive the antenna signal, The measurement circuit additionally includes a comparator configured to compare: indicating the envelope voltage of the signal received by the antenna for a first one of the at least two impedance levels, and Indicating the envelope voltage of the signal received by the antenna for a second of the at least two impedance levels, and An output is provided indicating which of the envelope voltages is highest for setting the impedance tuning circuit to an impedance level of the at least two impedance levels that produces the highest envelope voltage.
  8. 8. The wireless receiver circuit of any of claims 6-7, wherein, The control circuit is configured to receive the output of the comparator and output the initialization signal to the timing circuit based on the output of the comparator, wherein Each of the one or more delay lines of the timing circuit is configured to output a respective one of the one or more delay signals.
  9. 9. A method of operating a wireless receiver circuit, the wireless receiver circuit comprising: A terminal for coupling to an antenna; an impedance tuning circuit coupled between the terminal and a receiver path, a measurement circuit coupled to the impedance tuning circuit, and a timing circuit including one or more delay lines, the method comprising: Providing an initialization signal to the timing circuit based on a signal received by the antenna; Receiving one or more delay signals from the one or more delay lines; The one or more delay signals are provided to control one or both of the impedance tuning circuit and the measurement circuit for measuring, for each of at least two impedance levels provided by the impedance tuning circuit, a voltage or current indicative of a signal received by the antenna.
  10. 10. An RFID tag comprising a wireless receiver circuit according to any one of claims 1 to 8.

Description

Receiver circuit Technical Field The present disclosure relates to a receiver circuit, and in particular, to a wireless receiver circuit. The present disclosure also relates to a method for controlling the wireless receiver circuit, and also to an electronic device comprising the wireless receiver circuit. Background Impedance matching between circuit components is critical to ensure good coupling between wirelessly coupled devices, such as Radio Frequency ID (RFID) tags. The coupling between devices may be improved by tuning the impedance of the wireless receiver circuit. Obtaining a good impedance match between components in a wireless receiver circuit is challenging and typically consumes additional power, resulting in overall performance degradation. Disclosure of Invention According to a first aspect of the present disclosure, there is provided a wireless receiver circuit comprising: a terminal for coupling to an antenna; An impedance tuning circuit coupled between the terminal and the receiver path, wherein the impedance tuning circuit is controllable to provide at least two impedance levels; A measurement circuit coupled to the impedance tuning circuit and configured to measure, for each of the at least two impedance levels, a voltage or current indicative of a signal received by the antenna, and A timing circuit comprising one or more delay lines, wherein the one or more delay lines are configured to receive an initialization signal from the measurement circuit or the impedance tuning circuit and to provide one or more delay signals to control one or both of the measurement circuit and the impedance tuning circuit to measure the voltage at each of the two impedance levels. In one or more examples, the initialization signal is based on a signal received from the antenna via the terminal. In one or more examples, the initialization signal may be provided from a control circuit to the timing circuit or the one or more delay lines. In one or more embodiments, said controlling one or both of said measuring circuit and said impedance tuning circuit to measure said voltage at each of said two impedance levels comprises: The impedance tuning circuit is configured to receive at least one of the one or more delayed signals to sequentially select one of the at least two impedance levels. In one or more embodiments, the controlling one or both of the measurement circuit and the impedance tuning circuit to measure the voltage at each of the two impedance levels includes the measurement circuit being configured to receive at least one of the one or more delay signals to: sampling and holding a first voltage for a first of the at least two impedance levels; Sampling and holding a second voltage for a second of the at least two impedance levels, and The first voltage and the second voltage are compared for determining which of the first and second impedance levels of the at least two impedance levels to select to receive future further signals. In one or more embodiments, said controlling one or both of said measuring circuit and said impedance tuning circuit to measure said voltage of each of said at least two impedance levels comprises: One of the at least two impedance levels is selected based on which impedance level provides the highest voltage or current measured by the measurement circuit. In one or more embodiments, the wireless receiver circuit includes a control circuit including one or more logic gates configured to provide the control to one or both of the measurement circuit and the impedance tuning circuit, and wherein the one or more delay signals are configured to control the one or more logic gates. In one or more embodiments, the wireless receiver circuit includes an envelope detector coupled between the impedance tuning circuit and the measurement circuit, the envelope detector configured to output an envelope voltage indicative of an envelope of the signal received by the antenna, wherein the envelope voltage includes the voltage indicative of the signal received by the antenna. In one or more embodiments, the measurement circuit additionally includes a comparator configured to compare: indicating the envelope voltage of the signal received by the antenna for a first one of the at least two impedance levels, and Indicating the envelope voltage of the signal received by the antenna for a second of the at least two impedance levels, and An output is provided indicating which of the envelope voltages is highest for setting the impedance tuning circuit to an impedance level of the at least two impedance levels that produces the highest envelope voltage. In one or more embodiments, the control circuit is configured to receive the output of the comparator and output the initialization signal to the timing circuit based on the output of the comparator, wherein Each of the one or more delay lines of the timing circuit is configured to output a respective one of the one or more delay signals. In one or m