Wireless electronic device with calibrated reflectometer
First Claim
1. An electronic device, comprising:
- radio-frequency transceiver circuitry;
an antenna;
a transmission line path that couples the antenna to the radio-frequency transceiver circuitry;
a reflectometer coupled in the transmission line path between the antenna and the radio-frequency transceiver circuitry; and
a calibration circuit coupled between the reflectometer and the antenna, wherein the reflectometer comprises;
a feedback receiver;
first and second terminations of identical impedance that are coupled to ground;
a directional coupler with first and second ports;
a first switch that couples the first port to the first termination in a first configuration and couples the first port to the feedback receiver in a second configuration; and
a second switch that couples the second port to the second termination in a first configuration and couples the second port to and the feedback receiver in a second configuration.
2 Assignments
0 Petitions
Accused Products
Abstract
An electronic device may have control circuitry that uses a reflectometer to measure antenna impedance during operation. The reflectometer may have a directional coupler that is coupled between radio-frequency transceiver circuitry and an antenna. A calibration circuit may be coupled between the directional coupler and the antenna. The calibration circuit may have a first port coupled to the antenna, a second port coupled to the directional coupler, and a third port that is coupled to a calibration resistance. The reflectometer may have terminations of identical impedance that are coupled to ground. Switching circuitry in the reflectometer may be used to route signals from the directional coupler to a feedback receiver for measurement by the control circuitry or to ground through the terminations. Calibrated antenna reflection coefficient measurements may be used in dynamically adjusting the antenna.
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Citations
22 Claims
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1. An electronic device, comprising:
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radio-frequency transceiver circuitry; an antenna; a transmission line path that couples the antenna to the radio-frequency transceiver circuitry; a reflectometer coupled in the transmission line path between the antenna and the radio-frequency transceiver circuitry; and a calibration circuit coupled between the reflectometer and the antenna, wherein the reflectometer comprises; a feedback receiver; first and second terminations of identical impedance that are coupled to ground; a directional coupler with first and second ports; a first switch that couples the first port to the first termination in a first configuration and couples the first port to the feedback receiver in a second configuration; and a second switch that couples the second port to the second termination in a first configuration and couples the second port to and the feedback receiver in a second configuration. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 19, 20, 21)
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10. A method of operating an electronic device having radio-frequency transceiver circuitry coupled to an antenna with a transmission line path, wherein the antenna includes adjustable circuitry, the method comprising:
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with control circuitry in the electronic device, controlling a reflectometer interposed in the transmission line path to gather a calibrated reflection coefficient measurement for the antenna; and adjusting the adjustable circuitry of the antenna based on the calibrated reflection coefficient measurement for the antenna. - View Dependent Claims (11, 12, 13, 14, 22)
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15. An electronic device, comprising:
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a housing; control circuitry in the housing; radio-frequency transceiver circuitry; an antenna; a transmission line path that couples the antenna to the radio-frequency transceiver circuitry; a reflectometer coupled in the transmission line path between the antenna and the radio-frequency transceiver circuitry, wherein the reflectometer is controlled by the control circuitry; and a calibration circuit coupled between the reflectometer and the antenna, wherein the calibration circuit comprises; a calibration resistor; and a switch having a first port coupled to the antenna, a second port coupled to the reflectometer, and a third port coupled to the calibration resistor. - View Dependent Claims (16, 17, 18)
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Specification