Radio frequency energy-transmitting apparatus with location detection function and radio frequency energy-harvesting apparatus and radio frequency energy-transmitting method with location detection function

Abstract

A radio frequency energy-transmitting apparatus includes a harmonic radar unit and a harmonic radar control unit. The harmonic radar unit transmits a radar wave with a fundamental frequency. After a radio frequency energy-harvesting apparatus receives the radar wave, the radio frequency energy-harvesting apparatus generates and transmits a radar reflection harmonic wave. A frequency of the radar reflection harmonic wave is a multiple frequency of the radar wave. After the harmonic radar unit receives the radar reflection harmonic wave, the harmonic radar control unit determines a location of the radio frequency energy-harvesting apparatus. According to the location of the radio frequency energy-harvesting apparatus, the harmonic radar control unit controls the harmonic radar unit, so that a radar wave beam of the radar wave transmitted from the harmonic radar unit is directed toward the location of the radio frequency energy-harvesting apparatus.

What is claimed is: 
     
         1 . A radio frequency energy-transmitting apparatus applied to a radio frequency energy-harvesting apparatus, the radio frequency energy-transmitting apparatus comprising:
 a harmonic radar unit; and   a harmonic radar control circuit electrically connected to the harmonic radar unit,
 wherein the harmonic radar unit transmits a radar wave scanning to a space; after the radio frequency energy-harvesting apparatus receives the radar wave, according to the radar wave, the radio frequency energy-harvesting apparatus generates a radar reflection harmonic wave; a frequency of the radar reflection harmonic wave is different from a frequency of the radar wave; the radio frequency energy-harvesting apparatus transmits the radar reflection harmonic wave; after the harmonic radar unit receives the radar reflection harmonic wave, according to the radar reflection harmonic wave, the harmonic radar control unit determines a location of the radio frequency energy-harvesting apparatus; according to the location of the radio frequency energy-harvesting apparatus, the harmonic radar control unit controls the harmonic radar unit, so that a radar wave beam of the radar wave transmitted from the harmonic radar unit is directed toward the location of the radio frequency energy-harvesting apparatus. 
   
     
     
         2 . The radio frequency energy-transmitting apparatus in  claim 1 , wherein the frequency of the radar reflection harmonic wave is an integral multiple frequency of the radar wave. 
     
     
         3 . The radio frequency energy-transmitting apparatus in  claim 2 , wherein the frequency of the radar reflection harmonic wave is a double frequency of the radar wave. 
     
     
         4 . The radio frequency energy-transmitting apparatus in  claim 3  further applied to a power source, wherein the harmonic radar unit comprises:
 a power divider electrically connected to the power source; 
 a switchable phase delay module electrically connected to the power divider and the harmonic radar control unit; and 
 an antenna array electrically connected to the switchable phase delay module,
 wherein the power source transmits a power to the power divider; the power divider transmits splits the power into some equal parts and transmits the equal power to each individual delay path in the switchable phase delay module; according to the location of the radio frequency energy-harvesting apparatus, the harmonic radar control unit controls the switchable phase delay module to control a phase of the power, so that the radar wave beam of the radar wave transmitted from the antenna array is directed toward the location of the radio frequency energy-harvesting apparatus. 
 
 
     
     
         5 . The radio frequency energy-transmitting apparatus in  claim 4 , wherein the harmonic radar control unit comprises:
 a harmonic radar control circuit electrically connected to the switchable phase delay module; and   a location determination circuit electrically connected to the harmonic radar control circuit,   wherein the harmonic radar unit further comprises:   a harmonic receiving antenna; and   a harmonic power detector electrically connected to the harmonic receiving antenna and the location determination circuit,
 wherein after the location determination circuit receives the radar reflection harmonic wave through the harmonic receiving antenna and the harmonic power detector, according to a comparative result between an intensity of the radar reflection harmonic wave and an intensity of a background harmonic noise, the location determination circuit determines whether the radio frequency energy-harvesting apparatus exists or not, to generate a location signal related with the location of the radio frequency energy-harvesting apparatus; the location determination circuit transmits the location signal to the harmonic radar control circuit. 
   
     
     
         6 . The radio frequency energy-transmitting apparatus in  claim 5 , wherein the harmonic radar control unit controls the switchable phase delay module by an analog modulation control mode. 
     
     
         7 . A radio frequency energy-harvesting apparatus applied to a radio frequency energy-transmitting apparatus with a location detection function, the radio frequency energy-harvesting apparatus comprising:
 a direct current signal receiving-processing unit;   a rectification and harmonic generation unit electrically connected to the direct current signal receiving-processing unit; and   a radar wave receiving-transmitting unit electrically connected to the rectification and harmonic generation unit,
 wherein the radio frequency energy-transmitting apparatus transmits a radar wave scanning to a space; after the radar wave receiving-transmitting unit receives the radar wave, according to the radar wave, the radar wave receiving-transmitting unit generates an alternating current signal; the radar wave receiving-transmitting unit transmits the alternating current signal to the rectification and harmonic generation unit; the rectification and harmonic generation unit generates a radar reflection harmonic wave and a direct current signal; a frequency of the radar reflection harmonic wave is different from a frequency of the radar wave; the rectification and harmonic generation unit transmits the radar reflection harmonic wave to the radio frequency energy-transmitting apparatus through the radar wave receiving-transmitting unit; the rectification and harmonic generation unit transmits the direct current signal to the direct current signal receiving-processing unit. 
   
     
     
         8 . The radio frequency energy-harvesting apparatus in  claim 7 , wherein the frequency of the radar reflection harmonic wave is an integral multiple frequency of the radar wave. 
     
     
         9 . The radio frequency energy-harvesting apparatus in  claim 8 , wherein the frequency of the radar reflection harmonic wave is a double frequency of the radar wave. 
     
     
         10 . The radio frequency energy-harvesting apparatus in  claim 9 , wherein the radar wave receiving-transmitting unit comprises:
 a matching circuit electrically connected to the rectification and harmonic generation unit,   wherein after the radar wave receiving-transmitting unit receives the radar wave, according to the radar wave, the matching circuit processes the radar wave by a matching process to generate the alternating current signal; the matching circuit transmits the alternating current signal to the rectification and harmonic generation unit.   
     
     
         11 . The radio frequency energy-harvesting apparatus in  claim 10 , wherein the radar wave receiving-transmitting unit further comprises:
 a first selection switch electrically connected to the matching circuit; and   a second selection switch electrically connected to the matching circuit and the rectification and harmonic generation unit.   
     
     
         12 . The radio frequency energy-harvesting apparatus in  claim 11 , wherein the matching circuit comprises:
 a harmonic optimization matching sub-circuit electrically connected to the first selection switch and the second selection switch; and   an energy-harvesting optimization matching sub-circuit electrically connected to the first selection switch and the second selection switch,
 wherein if the direct current signal is less than a predetermined value, the first selection switch and the second selection switch are controlled, so that the harmonic optimization matching sub-circuit receives the radar wave; if the direct current signal is greater than or equal to the predetermined value, the first selection switch and the second selection switch are controlled, so that the energy-harvesting optimization matching sub-circuit receives the radar wave. 
   
     
     
         13 . The radio frequency energy-harvesting apparatus in  claim 12 , wherein the radar wave receiving-transmitting unit further comprises:
 a radar wave receiving antenna electrically connected to the first selection switch; and   a harmonic transmitting antenna electrically connected to the second selection switch and the rectification and harmonic generation unit,
 wherein the radar wave receiving antenna receives the radar wave and transmits the radar wave to the matching circuit through the first selection switch; the rectification and harmonic generation unit transmits the radar reflection harmonic wave to the radio frequency energy-transmitting apparatus through the harmonic transmitting antenna. 
   
     
     
         14 . The radio frequency energy-harvesting apparatus in  claim 13 , wherein the rectification and harmonic generation unit is a bridge rectifier. 
     
     
         15 . The radio frequency energy-harvesting apparatus in  claim 14  further comprising:
 a low pass filter electrically connected to the rectification and harmonic generation unit and the direct current signal receiving-processing unit; and 
 a selection switch controller electrically connected to the low pass filter, the first selection switch and the second selection switch, 
 wherein the selection switch controller controls the first selection switch and the second selection switch. 
 
     
     
         16 . The radio frequency energy-harvesting apparatus in  claim 15 , wherein the radar wave receiving antenna and the harmonic transmitting antenna are integrated as a dual-mode antenna. 
     
     
         17 . A radio frequency energy-transmitting method comprising:
 a. transmitting a radar wave scanning to a space;   b. after a radio frequency energy-harvesting apparatus receives the radar wave, according to the radar wave, the radio frequency energy-harvesting apparatus generating a radar reflection harmonic wave, wherein a frequency of the radar reflection harmonic wave is different from a frequency of the radar wave;   c. the radio frequency energy-harvesting apparatus transmitting the radar reflection harmonic wave;   d. after receiving the radar reflection harmonic wave, according to the radar reflection harmonic wave, determining a location of the radio frequency energy-harvesting apparatus; and   e. according to the location of the radio frequency energy-harvesting apparatus, controlling a radar wave beam of the radar wave directing toward the location of the radio frequency energy-harvesting apparatus.   
     
     
         18 . The radio frequency energy-transmitting method in  claim 17 , wherein the frequency of the radar reflection harmonic wave is an integral multiple frequency of the radar wave. 
     
     
         19 . The radio frequency energy-transmitting method in  claim 18 , wherein in the step d further comprises:
 a harmonic radar unit scanning and recording power intensities of a plurality of radar electric waves, and if the power intensity of the radar electric wave is greater than a background harmonic power intensity a power predetermined value, the harmonic radar unit determining that the radar electric wave is the radar reflection harmonic wave.   
     
     
         20 . The radio frequency energy-transmitting method in  claim 19 , wherein in the step d further comprises:
 if the power intensity of the radar electric wave is not greater than the background harmonic power intensity the power predetermined value, the harmonic radar unit determining that the radar electric wave is not the radar reflection harmonic wave, and then the harmonic radar unit eliminating the radar electric wave.