TWI825577B - Radio frequency radar device and method for detecting vital information and humidity - Google Patents

Abstract

The disclosure provides a method for detecting vital information and humidity using a radio frequency radar device. An incident radar signal is emitted to a field to detect the reflected radar signal reflected by an object to be measured and the reflected radar signal reflected by a humidity sensor tag. So that, the life information of the object and the humidity information detected by the humidity sensor tag can be obtained.

Description

Radio frequency radar device and method for detecting vital information and humidity

The present invention relates to a radar signal processing technology, in particular to a radio frequency radar device and a detection method of life information and humidity.

Although there are physiological information detection radars used to detect breathing and heartbeat, however, in applications such as patient care, long-term care of the elderly, and infant care, it is impossible to detect patients, the elderly, and infants who need to wear diapers at the same time. Measuring the moisture content of his diapers still showed insufficient results.

According to some embodiments, the method of detecting vital information and humidity includes: transmitting an incident radar signal to a field and receiving a reflected radar signal corresponding to the field; processing the reflected radar signal to obtain the body reflection signal and humidity sensing of the object to be measured The tag's tag reflects the signal; life information is obtained based on the phase information of the body's reflected signal; and humidity information is obtained based on the energy intensity of the tag's reflected signal.

According to some embodiments, a radio frequency radar device includes: a transmitting unit, a receiving unit, a demodulation unit and a processing unit. The transmitting unit is configured to transmit incident radar signals to the field. The receiving unit is configured to receive reflected radar signals corresponding to the field. The demodulation unit is coupled to the transmitting unit and the receiving unit, and is configured to process the reflected radar signal to obtain the body reflection signal of the object to be measured and the label reflection signal of the humidity sensing tag. The processing unit is coupled to the transmitting unit, the receiving unit and the demodulation unit, and is configured to obtain life information based on the phase information of the body reflected signal, and obtain humidity information based on the energy intensity of the tag reflected signal.

According to some embodiments, a radio frequency radar device includes a transmitting unit, a receiving unit, a first demodulation circuit, a second demodulation circuit and a processing unit. The transmitting unit is configured to transmit two incident radar signals of different frequencies to the field. The receiving unit is configured to receive reflected radar signals corresponding to the field. The first demodulation circuit is coupled to the transmitting unit and the receiving unit, receives the incident radar signal at the first frequency, and is configured to demodulate the reflected radar signal corresponding to the first frequency to obtain the body reflection signal. The second demodulation circuit is coupled to the transmitting unit and the receiving unit, receives the incident radar signal at the second frequency, and is configured to demodulate the reflected radar signal corresponding to the second frequency to obtain the tag reflection signal. The processing unit is coupled to the transmitting unit and the receiving unit, the first demodulation circuit and the second demodulation circuit, and is configured to obtain life information based on the phase information of the body reflected signal, and obtain humidity information based on the energy intensity of the tag reflected signal.

In summary, the radio frequency radar device and the method for detecting vital information and humidity according to some embodiments can measure vital information and humidity at the same time, saving device space and hardware costs.

As used herein, the term "coupled" means that two or more elements are in direct physical or electrical contact with each other, or are in indirect physical or electrical contact with each other.

Referring to FIG. 1 , which is a schematic diagram of a usage state of a radio frequency radar device 100 according to some embodiments. The radio frequency radar device 100 emits a radar signal (hereinafter referred to as "incident radar signal FH"). The incident radar signal FH is transmitted to the field and is reflected back to the radio frequency radar device 100 by the object to be measured 900, the humidity sensing tag 200, the environment, etc. The radar signal reflected by the object to be measured 900 is hereinafter referred to as the “reflected radar signal FN”, and the radar signal reflected by the humidity sensing tag 200 is referred to as the “reflected radar signal FN’”.

In some embodiments, the radio frequency radar device 100 is a continuous wave (Continuous Wave, CW) radar.

Referring to FIG. 2 and FIG. 3 together, FIG. 2 is a schematic structural diagram of a radio frequency radar device 100 according to some embodiments, and FIG. 3 is a flow chart of a method for detecting life information and humidity according to some embodiments. The radio frequency radar device 100 includes a transceiver 110, a demodulation unit 120 and a processing unit 130. The transceiver 110 includes a transmitting unit 111 and a receiving unit 112. The transmitting unit 111 is configured to transmit the incident radar signal FH (step S31). The transmitting unit 111 includes a transmitting antenna and an oscillation circuit (not shown). The oscillator circuit can generate a radio frequency signal, which is emitted through the transmitting antenna. Therefore, the transmitting antenna must be designed to work effectively within the transmitting frequency range. Here, the transmitting antenna may be a patch antenna (Patch Antenna), but the present disclosure is not limited thereto.

The receiving unit 112 is configured to receive the reflected radar signals FN, FN' (step S32). The receiving unit 112 includes a receiving antenna, and the working frequency range of the receiving antenna must cover the frequencies of the reflected radar signals FN and FN’. Optionally, when the working frequency range of a receiving antenna can cover the frequencies of reflected radar signals FN and FN’, only one receiving antenna is required. On the contrary, two receiving antennas can be used, each operating in a different frequency range, to cover the frequencies of reflected radar signals FN and FN’ respectively. It can be understood that if only the reflected radar signals FN and FN' of the same frequency are received, there may be only one receiving antenna.

The demodulation unit 120 is coupled to the transmitting unit 111 and the receiving unit 112 and is configured to process the reflected radar signals FN and FN' to obtain a body reflection signal Sb of the object to be measured 900 (step S33) and a label reflection of the humidity sensing tag 200 Signal St (step S35). The processing unit 130 is coupled to the transmitting unit 111, the receiving unit 112 and the demodulating unit 120 to control these units, and is configured to obtain a life information based on the phase information of the body reflection signal Sb (step S34), and based on the tag reflection signal St energy intensity to obtain humidity information (step S36). In this way, vital information and humidity information can be simultaneously obtained through the radio frequency radar device 100 . For example, when used in baby care applications, the baby's vital response and diaper status can be known at the same time. However, the invention is not limited to this application.

Before describing the operation principles of the demodulation unit 120 and the processing unit 130 in detail, the structure of the humidity sensing tag 200 is first described. Referring to FIG. 4 , which is a schematic structural diagram of the humidity sensing tag 200 according to the first embodiment. The humidity sensing tag 200 includes an input antenna 210, a frequency multiplication circuit 220, an RF-DC converter 230, an oscillator 240, an output antenna 250 and a humidity sensor 260.

The input antenna 210 is used to receive the incident radar signal FH transmitted from the radio frequency radar device 100 . Here, the input antenna 210 may be a double dipole patch antenna, but the disclosure is not limited thereto. The input antenna 210 is coupled to the frequency multiplication circuit 220 and the RF-DC converter 230 . The frequency multiplier circuit 220 receives the incident radar signal FH received by the input antenna 210 and multiplies the frequency of the incident radar signal FH, that is, a signal with a frequency of 2f0 is generated based on the incident radar signal FH with a frequency of f0 (or fundamental frequency signal) ( Or called frequency doubled signal). The RF-DC converter 230 is an energy collector that collects the incident radar signal FH energy received by the input antenna 210. A part of the radio frequency signal energy is collected by the RF-DC converter 230 and boosted to the operating voltage of other circuits. to provide the humidity sensing tag 200 operating voltage. Therefore, the humidity sensing tag 200 does not need to be equipped with an additional battery. However, in some embodiments, a battery may be used instead of the RF-DC converter 230 to provide the circuit operating voltage. The RF-DC converter 230 can be mainly implemented by a voltage multiplier composed of multiple diodes and multiple capacitors. The RF-DC converter 230 is also coupled to the oscillator 240 to provide operating voltage to the oscillator 240 . The oscillator 240 is coupled to the bias terminal of the frequency multiplier circuit 220 to generate a specific frequency signal to modulate the signal of the frequency multiplier circuit 220 . This specific frequency signal can be identified as a tag. Figure 4 illustrates the composition of the oscillator 240, which can be implemented by inverters G1, G2, resistors R1, R2, capacitor C1 and other components, but the disclosure is not limited thereto.

FIG. 4 also illustrates the composition of the frequency multiplication circuit 220, but does not limit the present disclosure. The frequency doubling circuit 220 is composed of a diode D1, a plurality of microstrip lines Sp1 to Sp6, a resistor R _bias , and a capacitor C2. The input end of the diode D1 is coupled to the microstrip lines Sp1 and Sp3, the resistor R _bias , the capacitor C2 and other components. The capacitor C2 is used as a bypass capacitor to filter out the frequency multiplied signal (2f0). The output of the frequency multiplier circuit 220 can start or stop oscillating by adjusting the bias voltage of the diode D1. The resistor R _bias serves as a bias resistor and is coupled to the oscillator 240 to control the modulation multiplication circuit 220 . The output end of the diode D1 is coupled to the microstrip lines Sp2, Sp4, Sp5, and Sp6, which form a high-pass filter to filter out the fundamental frequency signal (f0). Here, the length of the microstrip line Sp3 is a quarter wavelength of the fundamental frequency signal, and the lengths of the microstrip lines Sp4, Sp5, and Sp6 are a quarter wavelength of the doubled frequency signal.

The output antenna 250 is coupled to the frequency doubling circuit 220 to emit the modulated and frequency multiplied radio frequency signal, that is, the output is coupled to the frequency multiplied signal (2f0) as a specific frequency signal identified by the tag. The output antenna 250 is coupled to the humidity sensor 260 to form a humidity detection antenna. Humidity sensor 260 is a variable capacitor. Changes in the medium caused by humidity will affect the dielectric coefficient of the capacitor, thereby affecting the resonant frequency of the output antenna 250, causing the energy intensity of the frequency doubled signal (2f0) to change. Therefore, the radio frequency radar device 100 can learn the humidity change by detecting the signal intensity change of (2f0) of the frequency doubled signal. The humidity sensor 260 may be an interdigital capacitor or a parallel plate capacitor.

Refer to FIG. 5 , which is a schematic structural diagram of a humidity detection antenna according to an embodiment. The endpoint 258 is the signal feed end of the output antenna 250 and receives the signal of the frequency multiplier circuit 220 . The output antenna 250 is a patch antenna here, with a length L of 37.5 cm, a width W of 51 cm, and a feed section length L _inset of 9.5 cm. The humidity sensor 260 is an interdigital capacitor with 18 interdigitated electrodes interlaced with each other. Each electrode is 5 cm long, 0.6 cm wide, and 0.3 cm apart. The above specifications are only examples, and this disclosure is not limited thereto.

Refer to FIG. 6 , which is a schematic structural diagram of a humidity sensor 260 according to an embodiment. Here, the humidity sensor 260 is a parallel plate capacitor having two parallel plates 261 and 262 spaced up and down.

Refer to FIG. 7 , which is a schematic structural diagram of a humidity sensor 260 according to another embodiment. Here, the humidity sensor 260 is an annular interdigital capacitor, including an upper ring 263 and a lower ring 264 arranged at staggered annular intervals.

Referring to FIG. 8 , which is a schematic structural diagram of a radio frequency radar device 100 according to the first embodiment. It should be noted here that the demodulation unit 120 includes a first demodulation circuit 123 and a second demodulation circuit 124. The first demodulation circuit 123 is configured to demodulate the reflected radar signal FN reflected by the object to be measured 900 , so the frequency of the reflected radar signal FN is the same as the incident radar signal FH, which is f0. The second demodulation circuit 124 is configured to demodulate the reflected radar signal FN' that is backscattered by the humidity sensing tag 200. As explained above, the frequency of the reflected radar signal FN' is 2f0. Since the first demodulation circuits 123 are each responsible for demodulating signals of different frequencies, mutual influence of the body reflection signal Sb and the tag reflection signal St can be avoided.

The first demodulation circuit 123 is coupled to the transmitting unit 111 and the receiving unit 112 to receive the incident radar signal FH from the transmitting unit 111 and demodulate the reflected radar signal with the same frequency f0 according to the frequency (f0) corresponding to the incident radar signal FH. FN to obtain the body reflection signal Sb. The body reflection signal Sb can reflect the phase information resulting from the phase changes caused by the body movements of breathing and heartbeat.

The second demodulation circuit 124 is coupled to the transmitting unit 111 and the receiving unit 112, receives the frequency-multiplied incident radar signal FH (2f0) from the transmitting unit 111, and is configured to operate according to the doubled frequency (2f0) corresponding to the incident radar signal FH. Demodulate the reflected radar signal FN' to obtain the tag reflected signal St. Here, the transmitting unit 111 includes a frequency multiplier to generate the frequency multiplied signal 2f0.

The processing unit 130 includes a control circuit 135, an analog-to-digital converter 136 and an arithmetic circuit 137. The control circuit 135 is coupled to the transmitting unit 111, the receiving unit 112, the first demodulation circuit 123, the second demodulation circuit 124 and the arithmetic circuit 137, and is configured to control the operation of these components. The two analog-to-digital converters 136 are respectively coupled to the first demodulation circuit 123 and the second demodulation circuit 124 to convert the body reflection signal Sb and the tag reflection signal St into digital signals. The computing circuit 137 is coupled to the analog-to-digital converter 136 to perform digital signal processing on the digital signal, such as removing noise, removing high-frequency signals, and removing inappropriate respiratory harmonics, so as to calculate breathing and heartbeat from the body reflected signal Sb. information. Specifically, life information such as breathing and heartbeat can be obtained based on the oscillation frequency of the phase information of the body reflection signal Sb, and each information type can be distinguished based on its usual frequency range. On the other hand, the computing circuit 137 can determine the energy intensity of the tag reflection signal St, and thereby identify the humidity information of the humidity sensor 260 .

Referring to FIG. 9 , a frequency response diagram of the humidity detection antenna shown in FIG. 5 under different humidity environments is shown. The suitable resonant frequency when designed to be dry is the working frequency of the tag. It can be seen that when dry, the intensity of the reflected radar signal FN’ is strong because the antenna circuit of the humidity detection antenna is well coordinated. When it is wet, the intensity of the reflected radar signal FN’ becomes weaker due to the poor coordination of the antenna circuit of the humidity detection antenna. In this way, the energy intensity of the reflected radar signal FN’ can be detected to determine the humidity. In addition, when the humidity reaches a certain level, the reflected radar signal FN' signal is too weak, making it impossible for the radio frequency radar device 100 to read the specific frequency mentioned above as a tag identification, which can also be used as a condition for judging humidity.

Referring to FIG. 10 , it is a schematic diagram of the signal strength of the tag reflection signal St of the humidity detection antenna shown in FIG. 5 under different humidity environments. It can be seen that under different resonant frequencies, as the humidity increases, the signal intensity may gradually increase or decrease. For example, it is gradually decreasing at 868MHz and gradually increasing at 840MHz. Therefore, the humidity information can be determined based on the energy intensity of the tag reflection signal St compared to a threshold, for example, higher than a certain threshold or lower than a certain threshold. This threshold can also be determined in advance by experimentally measuring changes in the desired operating frequency under different humidity conditions.

In some embodiments, since the radio frequency radar device 100 and the humidity sensing tag 200 also change energy intensity, humidity determination may be affected. Therefore, when the diaper is still dry at the beginning, the energy intensity during drying can be recorded first, and then the humidity information can be determined based on the change in energy intensity compared with a threshold. Alternatively, when the radio frequency radar device 100 initially operates, the energy intensity of the reflected radar signal FN' can be recorded first. When the change in energy intensity exceeds the threshold, it can be determined that the diaper is wet.

In some embodiments, the frequency f0 of the first embodiment is 865-868 MHz, but the present disclosure is not limited thereto.

Please refer to Figure 11 and Figure 12 together. FIG. 11 is a schematic structural diagram of a radio frequency radar device 100 according to the second embodiment. FIG. 12 is a schematic structural diagram of a humidity sensing tag 200 according to the second embodiment. The difference from the first embodiment mentioned above is that the humidity sensing tag 200 of this embodiment does not have the frequency multiplier circuit 220 but is replaced by a mixer 270. Therefore, the frequency of the reflected radar signal FN' is the same as the frequency of the reflected radar signal FN' and the incident frequency of the reflected radar signal FN'. The radar signals FH are the same, both at frequency f0. Therefore, the demodulation unit 120 of this embodiment is not divided into a first demodulation circuit 123 and a second demodulation circuit 124, but is only a demodulation circuit for demodulating according to the frequency (f0) of the incident radar signal FH. signal to obtain the body reflection signal Sb and the tag reflection signal St. This can save hardware costs. In order to avoid the mutual influence between the reflected radar signals FN and FN’, the oscillation frequency of the oscillator 240 should avoid the frequencies of breathing and heartbeat. Therefore, the body reflection signal Sb and the tag reflection signal St can be distinguished based on the phase oscillation frequency of the reflected radar signals FN and FN' (that is, the changing frequency of the phase information).

Figure 13 is a flow chart of a method for detecting vital information and humidity according to the third embodiment. The radio frequency radar device 100 of the first embodiment receives two frequency signals, respectively f0 and 2f0. The radio frequency radar device 100 of the second embodiment receives a frequency signal of f0. The radio frequency radar device 100 of the third embodiment also receives signals of two different frequencies, but the relationship is not twice the same. In some embodiments, a frequency band commonly used by radar for measuring vital information, such as 2.4 GHz or 5 GHz, can be used as the frequency of the incident radar signal FH for measuring the body reflection signal Sb. In this way, the detection sensitivity can be improved. On the other hand, the 865-868MHz frequency band suitable for tag use is used as the frequency of the incident radar signal FH for measuring the tag reflected signal St. Here, the antenna of the transmitting unit 111 includes a millimeter wave antenna (such as an Antipodal Vivaldi antenna) and an ultra-high frequency (UHF) band antenna.

Referring to FIG. 13 , in step S41 , two incident radar signals FH of different frequencies are transmitted to the field. Next, in step S42, the reflected radar signals FN and FN' corresponding to the field are received. Next, the reflected radar signal FN is demodulated based on the frequency of one of the incident radar signals FH, thereby obtaining the body reflected signal Sb (step S43), and life information is obtained based on the phase information of the body reflected signal Sb (step S44). On the other hand, the reflected radar signal FN' is demodulated based on the frequency of another incident radar signal FH to obtain the tag reflected signal St (step S45), and the humidity information is obtained based on the energy intensity of the tag reflected signal St (step S46).

Refer to FIG. 14 , which is a schematic diagram of time-division multiplexing according to some embodiments. The incident radar signal FH of the second embodiment of the third embodiment can be transmitted in a time-division duplex manner. In the first mode, the incident radar signal FH used to measure the body reflection signal Sb is emitted, and in the second mode, the incident radar signal FH used to measure the tag reflection signal St is emitted.

In some embodiments, the control circuit 135, the analog-to-digital converter 136 and the arithmetic circuit 137 can be independent or integrated together, and can be components such as a processor, a microprocessor, and a system chip.

In summary, the radio frequency radar device and the method for detecting vital information and humidity according to some embodiments can measure vital information and humidity at the same time, saving device space and hardware costs.

100: Radio frequency radar device 110: Transceiver 111: Transmitting unit 112: Receiving unit 120: Demodulation unit 123: First demodulation circuit 124: Second demodulation circuit 130: Processing unit 135: Control circuit 136: Analog-to-digital converter 137: Arithmetic circuit 200: Humidity sensing tag 210: Input antenna 220: Frequency multiplier circuit 230: RF-DC converter 240: Oscillator 250: Output antenna 258: Endpoint 260: Humidity sensor 261, 262: Parallel plate 263: Upper ring 264: Lower ring 270: Mixer 900: Object to be measured FH: Incident radar signal FN, FN': Reflected radar signal Sb: Body reflected signal St: Tag reflected signal Sp1~Sp6: Microstrip line S31~S36 : Steps S41~S46: Steps R1, R2, R _bias : Resistors C1, C2: Capacitor D1: Diode G1, G2: Inverter L, L _inset : Length W: Width

[Fig. 1] is a schematic diagram of the usage state of a radio frequency radar device according to some embodiments. [Fig. 2] is an architectural schematic diagram of a radio frequency radar device according to some embodiments. [Figure 3] is a flow chart of a method for detecting vital information and humidity according to some embodiments. [Fig. 4] is a schematic structural diagram of a humidity sensing tag according to the first embodiment. [Fig. 5] is a schematic structural diagram of a humidity detection antenna according to an embodiment. [Fig. 6] is a schematic structural diagram of a humidity sensor according to an embodiment. [Fig. 7] is a schematic structural diagram of a humidity sensor according to another embodiment. [Fig. 8] is a schematic structural diagram of a radio frequency radar device according to the first embodiment. [Figure 9] is a frequency response diagram of the humidity detection antenna shown in Figure 5 under different humidity environments. [Figure 10] is a schematic diagram of the signal strength of the tag reflected signal from the humidity detection antenna shown in Figure 5 in different humidity environments. [Fig. 11] is a schematic structural diagram of a radio frequency radar device according to the second embodiment. [Fig. 12] is a schematic structural diagram of a humidity sensing tag according to the second embodiment. [Fig. 13] is a flow chart of a method for detecting vital information and humidity according to the third embodiment. [Figure 14] is a schematic diagram of time-sharing multiplexing according to some embodiments.

100: Radio frequency radar device

200: Humidity sensing tag

900:Object to be tested

FH: incident radar signal

FN, FN’: reflected radar signal

Claims (18)

A method for detecting life information and humidity, suitable for a radio frequency radar device. The radio frequency radar device includes a transmitting unit, a receiving unit, a demodulation unit and a processing unit. The method for detecting life information and humidity includes: An incident radar signal is transmitted to a field area through the transmitting unit, and a reflected radar signal corresponding to the field field is received through the receiving unit; the reflected radar signal is demodulated at two different frequencies through the demodulation unit, or demodulated The reflected radar signal is distinguished by different phase oscillation frequencies to obtain a body reflection signal of an object to be measured and a tag reflection signal of a humidity sensing tag respectively; through the processing unit, based on a phase information of the body reflection signal, Obtain a life information; and obtain a humidity information through the processing unit according to an energy intensity of the signal reflected by the tag. The method for detecting vital information and humidity as described in claim 1, wherein the body reflection signal is obtained by demodulating the reflection radar signal based on the frequency corresponding to the incident radar signal, and the tag reflection signal is obtained based on the frequency corresponding to the incident radar signal. The radar signal is obtained by demodulating the reflected radar signal at twice the frequency. The method for detecting vital information and humidity as described in claim 1, wherein the body reflection signal and the tag reflection signal are obtained by demodulating the reflection radar signal based on the frequency corresponding to the incident radar signal. The method for detecting life information and humidity as described in claim 1, wherein the humidity information is determined based on the energy intensity of the signal reflected by the tag compared to a threshold. The method for detecting life information and humidity as described in claim 1, wherein the humidity information is determined based on the change in the energy intensity of the tag's reflected signal compared with a threshold. The method for detecting life information and humidity as described in claim 1 further includes: distinguishing the type of the obtained life information based on the oscillation frequency of the phase information. The method for detecting life information and humidity as described in claim 1 further includes: transmitting the incident radar signal of another different frequency to the field. The method for detecting vital information and humidity as described in claim 7, wherein the body reflection signal is obtained by demodulating the reflection radar signal based on the frequency corresponding to one of the two incident radar signals, and the tag reflection signal is Obtained by demodulating the reflected radar signal based on a frequency corresponding to the other of the two incident radar signals. The method for detecting life information and humidity as described in claim 7, wherein the two incident radar signals are transmitted in a time division duplex mode. A radio frequency radar device includes: a transmitting unit configured to transmit an incident radar signal to a field area; a receiving unit configured to receive a reflected radar signal corresponding to the field area; a demodulation unit coupled to the transmitting unit and The receiving unit is configured to demodulate the reflected radar signal at two different frequencies, or to oscillate frequencies with different phases when demodulating the reflected radar signal. rate differentiation to respectively obtain a body reflection signal of an object to be measured and a label reflection signal of a humidity sensing tag; and a processing unit coupled to the transmitting unit, the receiving unit and the demodulation unit, configured as A phase information of the signal reflected by the body is used to obtain life information, and a humidity information is obtained based on an energy intensity of the signal reflected by the tag. The radio frequency radar device according to claim 10, wherein the demodulation unit includes: a first demodulation circuit coupled to the transmitting unit and the receiving unit, receiving the incident radar signal from the transmitting unit and configured to correspond to Demodulating the reflected radar signal at the frequency of the incident radar signal to obtain the body reflected signal; and a second demodulation circuit, coupled to the transmitting unit and the receiving unit, receiving the frequency multiplied incident signal from the transmitting unit a radar signal, and is configured to demodulate the reflected radar signal based on twice the frequency corresponding to the incident radar signal to obtain the tag reflected signal. The radio frequency radar device of claim 10, wherein the demodulation unit is a demodulation circuit that receives the incident radar signal from the transmitting unit and is configured to demodulate the reflected radar signal according to a frequency corresponding to the incident radar signal. . The radio frequency radar device of claim 10, wherein the processing unit determines the humidity information based on a result of comparing the energy intensity of the tag's reflected signal with a threshold. The radio frequency radar device of claim 10, wherein the processing unit determines the humidity information based on the change in the energy intensity of the tag's reflected signal compared with a threshold. The radio frequency radar device as claimed in claim 10, wherein the processing unit distinguishes the type of the obtained life information based on the oscillation frequency of the phase information. A radio frequency radar device includes: a transmitting unit configured to transmit two incident radar signals of different frequencies to a field; a receiving unit configured to receive a reflected radar signal corresponding to the field; a first demodulation circuit, coupled Connect the transmitting unit and the receiving unit, receive the incident radar signal at a first frequency, and be configured to demodulate the reflected radar signal corresponding to the first frequency to obtain a body reflection signal; a second demodulation A circuit coupled to the transmitting unit and the receiving unit, receives the incident radar signal at a second frequency, and is configured to demodulate the reflected radar signal corresponding to the second frequency to obtain a tag reflected signal; and a A processing unit, coupled to the transmitting unit and the receiving unit, the first demodulation circuit and the second demodulation circuit, is configured to obtain a life information based on a phase information of the body reflection signal, and to obtain a life information based on the tag reflection signal An energy intensity, obtain a humidity information. The radio frequency radar device according to claim 16, wherein the antenna of the transmitting unit includes a millimeter wave antenna and an ultra-high frequency band antenna. The radio frequency radar device as claimed in claim 16, wherein the processing unit is configured to control the two incident radar signals to be transmitted staggered in a time division duplex manner.

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