Granted Patent B2

US 11,095,337 · App. 16/894,821 · Granted Aug 17, 2021

Inventor: Shahriar Rokhsaz (Austin, TX)

Assignee: RFMicron, Inc.

H04B1/713H03J3/20H04B5/0062H04B17/318H04W4/80H03J2200/10

Abstract

Claims (147)

1. A communication system comprises:

a passive wireless sensor operable to:

receive a radio frequency (RF) signal, wherein the RF signal includes a carrier frequency signal and a modulated sense request signal;

generate a power supply voltage from the carrier frequency signal;

determine received signal strength (RSSI) of the RF signal based on the power supply voltage;

determine whether the RSSI is at a desired level; and

when the RSSI is at the desired level:

generate a response RF signal, wherein the response RF signal includes the carrier frequency and a coded sense response signal, wherein the coded sense response signal is representative of a sensed environmental condition, wherein the sensed environmental condition affects impedance of a front-end of the passive wireless sensor to produce an affected impedance, and wherein the passive wireless sensor generates the coded sense response signal based on tuning the affected impedance to resonate with the carrier frequency signal; and

a sensor computing device including a transceiver, memory, and a processing module operably coupled to the transceiver and the memory, wherein the processing module is operable to:

transmit the RF signal;

receive the response RF signal; and

generate an environmental condition value based on the coded sense response signal and environmental conversion information.

2. The communication system of claim 1 further comprises:

when the RSSI is not at the desired level, the passive wireless sensor is operable to:

send a RSSI signal to the sensor computing device; and

wherein the sensor computing device is operable to:

determine whether to adjust transmit power of the RF signal based on the RSSI signal; and

when the processing module of the sensor computing device determines to adjust transmit power of the RF signal:

the sensor computing device is operable to:

 adjust the transmit power to produce an adjusted transmit power; and

 resend the RF signal at the adjusted transmit power.

3. The communication system of claim 1 further comprises:

the passive wireless sensor is further operable to:

prior to determining whether the RSSI is at the desired level, send a RSSI signal to the sensor computing device; and

the processing module of the sensor computing device is further operable to:

determine whether to adjust transmit power of the RF signal based on the RSSI signal; and

when processing module of the sensor computing device determines to adjust transmit power of the RF signal:

adjust the transmit power to produce an adjusted transmit power; and

resend the RF signal at the adjusted transmit power.

4. The communication system of claim 1 further comprises:

the processing module of the sensor computing device is further operable to:

receive another response RF signal that includes the carrier frequency and an RSSI signal;

determine a coded value error factor based on the RSSI signal and the desired level;

adjust a coded value of the coded sensed response signal based on the coded value error factor to produce an adjusted coded value; and

generate the environmental condition value based on the adjusted coded value and the environmental conversion information.

5. The communication system of claim 1 further comprises:

the passive wireless sensor is further operable to:

down convert the RF signal to recover the sense request signal;

tune the impedance of the front-end of the passive wireless sensor to resonate with the carrier frequency, wherein the front-end includes a sensing element for sensing an environmental condition and wherein the sensing of the environmental condition by the sensing element alters the impedance of the front-end; and

generate the coded sense response signal as a representation of the tuning of the impedance of the front-end.

6. The communication system of claim 5 , wherein the passive wireless sensor is further operable to generate the environmental condition value by:

determining a type of environmental condition being sensed by the passive wireless sensor;

selecting, as the environmental conversion information, one of a plurality of environmental conversion databases based on the type of environmental condition;

recovering a coded value from the coded sense response signal; and

utilizing the coded value as an operand to the one of the plurality of environmental conversion databases to generate the environmental condition value.

7. The communication system of claim 1 , wherein the transceiver is a software defined transceiver for communicating with the passive wireless sensor.

8. The communication system of claim 1 further comprises:

the processing module of the sensor computing device is further operable to:

initiate a calibration process with the passive wireless sensor, wherein the passive wireless sensor is subjected to a known environmental condition;

receive a response calibration RF signal that includes the carrier frequency signal and a coded calibration signal from the passive wireless sensor, wherein the coded calibration signal is representative of the known environmental condition by the passive wireless sensor;

generate a calibration reference environmental condition value based on the coded calibration signal and the environmental conversion information;

compare the calibration reference environmental condition value with the known environmental condition;

when the calibration reference environmental condition value compares unfavorably with the known environmental condition:

adjust the environmental conversion information based on a difference between the calibration reference environmental condition value and the known environmental condition; or

send a calibration offset to the passive wireless sensor, wherein the passive wireless sensor utilizes the calibration offset when generating the coded sense response signal such that the coded sense response signal is a more accurate representation of the sensed environmental condition.

9. The communication system of claim 1 further comprises:

the processing module of the sensor computing device is further operable to:

transmit the RF signal to the passive wireless sensor using a frequency hopping scheme, wherein the RF signal includes, for a first hop of the frequency hopping scheme, a first carrier frequency signal of a plurality of carrier frequency signals and the modulated sense request signal and includes, for a second hop of the frequency hopping scheme, a second carrier frequency signal of the plurality of carrier frequency signals and the modulated sense request signal;

in response to the modulated sense request signal:

receive a first response RF signal that includes the first carrier frequency signal and a first coded sense response signal from the passive wireless sensor, wherein the first coded sense response signal is a first representative of the sensed environmental condition by the passive wireless sensor;

receive a second response RF signal that includes the second carrier frequency signal and a second coded sense response signal from the passive wireless sensor, wherein the second coded sense response signal is a second representative of the sensed environmental condition by the passive wireless sensor; and

generate the environmental condition value based on the first and second coded sense response signal, the environmental conversion information, the first carrier frequency signal, and the second carrier frequency signal.

10. The communication system of claim 1 , wherein the environmental condition value is a measure of one of:

temperature;

moisture;

pressure;

weight;

humidity;

gas percentages;

location proximity;

light; and

liquid properties.

11. The communication system of claim 1 further comprises:

the processing module of the sensor computing device is further operable to:

initiate a calibration process with the passive wireless sensor, wherein the passive wireless sensor is subjected to a first known environmental condition and to a second known condition;

receive a first response calibration RF signal that includes the carrier frequency signal and a first coded calibration signal from the passive wireless sensor, wherein the first coded calibration signal includes a first coded value corresponding to a measurement of the first known environmental condition by the passive wireless sensor;

receive a second response calibration RF signal that includes the carrier frequency signal and a second coded calibration signal from the passive wireless sensor, wherein the second coded calibration signal includes a second coded value corresponding to a measurement of the second known environmental condition by the passive wireless sensor;

store the first coded value as a first calibrated coded value for the first known condition; and

store the second coded value as a second calibrated coded value for the second known condition.

12. The method of claim 1 further comprises:

prior to determining whether the RSSI is at the desired level, sending, by the passive wireless sensor, a RSSI signal to the sensor computing device;

determining, by the processing module of the sensor computing device, whether to adjust transmit power of the RF signal based on the RSSI signal; and

when the processing module of the sensor computing device determines to adjust transmit power of the RF signal:

adjusting, by the processing module of the sensor computing device, the transmit power to produce an adjusted transmit power; and

resending, by the transceiver of the sensor computing device, the RF signal at the adjusted transmit power.

13. The method of claim 1 , wherein the transceiver of the sensor computing device is a software defined transceiver for communicating with the passive wireless sensor.

14. The method of claim 1 further comprises:

initiating, by the processing module of the sensor computing device, a calibration process with the passive wireless sensor, wherein the passive wireless sensor is subjected to a known environmental condition;

receiving, by the transceiver of the sensor computing device, a response calibration RF signal that includes the carrier frequency signal and a coded calibration signal from the passive wireless sensor, wherein the coded calibration signal is representative of the known environmental condition by the passive wireless sensor;

generating, by the processing module of the sensor computing device, a calibration reference environmental condition value based on the coded calibration signal and the environmental conversion information;

comparing, by the processing module of the sensor computing device, the calibration reference environmental condition value with the known environmental condition; and

when the calibration reference environmental condition value compares unfavorably with the known environmental condition:

adjusting, by the processing module of the sensor computing device, the environmental conversion information based on a difference between the calibration reference environmental condition value and the known environmental condition; or

sending, by the transceiver of the sensor computing device, a calibration offset to the passive wireless sensor, wherein the passive wireless sensor utilizes the calibration offset when generating the coded sense response signal such that the coded sense response signal is a more accurate representation of the sensed environmental condition.

15. A method for execution by a communication system, the method comprises:

transmitting, by a transceiver of a sensor computing device of the communication system, a radio frequency (RF) signal, wherein the RF signal includes a carrier frequency signal and a modulated sense request signal to a passive wireless sensor of the communication system;

generating, by the passive wireless sensor, a power supply voltage from the carrier frequency signal;

determining, by the passive wireless sensor, received signal strength (RSSI) of the RF signal based on the power supply voltage;

determining, by the passive wireless sensor, whether the RSSI is at a desired level; and

when the RSSI is at the desired level:

generating, by the passive wireless sensor, a response RF signal, wherein the response RF signal includes the carrier frequency and a coded sense response signal, wherein the coded sense response signal is representative of a sensed environmental condition, wherein the sensed environmental condition affects impedance of a front-end of the passive wireless sensor to produce an affected impedance, and wherein the passive wireless sensor generates the coded sense response signal based on tuning the affected impedance to resonate with the carrier frequency signal; and

receiving, by the transceiver of the sensor computing device, the response RF signal; and

generating, by a processing module of the sensor computing device, an environmental condition value based on the coded sense response signal and environmental conversion information.

16. The method of claim 15 further comprises:

when the RSSI is not at the desired level:

sending, by the passive wireless sensor, a RSSI signal to the sensor computing device;

receiving, by the transceiver of the sensor computing device, the RSSI signal; and

determining, by the processing module of the sensor computing device, whether to adjust transmit power of the RF signal based on the RSSI signal; and

when processing module of the sensor computing device determines to adjust transmit power of the RF signal:

adjusting, by the processing module of the sensor computing device, the transmit power to produce an adjusted transmit power; and

resending, by the transceiver of the sensor computing device, the RF signal at the adjusted transmit power.

17. The method of claim 15 further comprises:

receiving, by the transceiver of the sensor computing device, another response RF signal that includes the carrier frequency and an RSSI signal;

determining, by the processing module of the sensor computing device, a coded value error factor based on the RSSI signal and the desired level;

adjusting, by the processing module of the sensor computing device, a coded value of the coded sensed response signal based on the coded value error factor to produce an adjusted coded value; and

generating, by the processing module of the sensor computing device, the environmental condition value based on the adjusted coded value and the environmental conversion information.

18. The method of claim 15 further comprises:

down converting, by the passive wireless sensor, the RF signal to recover the sense request signal;

tuning, by the passive wireless sensor, the impedance of the front-end of the passive wireless sensor to resonate with the carrier frequency, wherein the front-end includes a sensing element for sensing an environmental condition and wherein the sensing of the environmental condition by the sensing element alters the impedance of the front-end; and

generating, by the passive wireless sensor, the coded sense response signal as a representation of the tuning of the impedance of the front-end.

19. The method claim 18 , wherein the environmental condition value is generated by:

determining a type of environmental condition being sensed by the passive wireless sensor;

selecting, as the environmental conversion information, one of a plurality of environmental conversion databases based on the type of environmental condition;

recovering a coded value from the coded sense response signal; and

utilizing the coded value as an operand to the one of the plurality of environmental conversion databases to generate the environmental condition value.

20. The method of claim 15 further comprises:

transmitting, by the transceiver of the sensor computing device, the RF signal to the passive wireless sensor using a frequency hopping scheme, wherein the RF signal includes, for a first hop of the frequency hopping scheme, a first carrier frequency signal of a plurality of carrier frequency signals and the modulated sense request signal and includes, for a second hop of the frequency hopping scheme, a second carrier frequency signal of the plurality of carrier frequency signals and the modulated sense request signal;

in response to the modulated sense request signal:

receiving, by the transceiver of the sensor computing device, a first response RF signal that includes the first carrier frequency signal and a first coded sense response signal from the passive wireless sensor, wherein the first coded sense response signal is a first representative of the sensed environmental condition by the passive wireless sensor;

receiving, by the transceiver of the sensor computing device, a second response RF signal that includes the second carrier frequency signal and a second coded sense response signal from the passive wireless sensor, wherein the second coded sense response signal is a second representative of the sensed environmental condition by the passive wireless sensor; and

generating, by the processing module of the sensor computing device, the environmental condition value based on the first and second coded sense response signal, the environmental conversion information, the first carrier frequency signal, and the second carrier frequency signal.

21. The method of claim 15 , wherein the environmental condition value is a measure of one of:

temperature;

moisture;

pressure;

weight;

humidity;

gas percentages;

location proximity;

light; and

liquid properties.

22. The method of claim 15 further comprises:

initiating, by the processing module of the sensor computing device, a calibration process with the passive wireless sensor, wherein the passive wireless sensor is subjected to a first known environmental condition and to a second known condition;

receiving, by the transceiver of the sensor computing device, a first response calibration RF signal that includes the carrier frequency signal and a first coded calibration signal from the passive wireless sensor, wherein the first coded calibration signal includes a first coded value corresponding to a measurement of the first known environmental condition by the passive wireless sensor;

receiving, by the transceiver of the sensor computing device, a second response calibration RF signal that includes the carrier frequency signal and a second coded calibration signal from the passive wireless sensor, wherein the second coded calibration signal includes a second coded value corresponding to a measurement of the second known environmental condition by the passive wireless sensor;

storing, by the memory of the sensor computing device, the first coded value as a first calibrated coded value for the first known condition; and

storing, by the memory of the sensor computing device, the second coded value as a second calibrated coded value for the second known condition.

Assignments (5)

Continuity (28)