1. An audio playing subsystem of a mobile electronic device, comprising:
a first audio player and a second audio player for playing a left channel audio and a right channel audio respectively;
a first audio receiver and a second audio receiver for receiving a first echo of the left channel audio and a second echo of the right channel audio in real time respectively; and
a control unit for compensating the left channel audio and the right channel audio according to the first echo and the second echo which are received, and controlling the first audio player and the second audio player to play a compensated left channel audio and a compensated right channel audio respectively, wherein the compensated left channel audio and the compensated right channel audio are able to offset the first echo and the second echo respectively.
2. The audio playing subsystem according to claim 1, wherein the control unit comprises a first filter and a second filter, the first filter takes an audio signal with the same frequency as the left channel audio and a smaller amplitude than the left channel audio as the first echo, the second filter takes an audio signal with the same frequency as the right channel audio and a smaller amplitude than the right channel audio as the second echo.
3. The audio playing subsystem according to claim 1, wherein the control unit comprises a first inverter, a first synthesizer, a second inverter and a second synthesizer, the first inverter receives the first echo and generates a first antiphase signal of the first echo, the first synthesizer synthesizes the first anti phase signal and the left channel audio into the compensated left channel audio, the second inverter receives the second echo and generates a second antiphase signal of the second echo, and the second synthesizer synthesizes the second antiphase signal and the right channel audio into the compensated right channel audio.
4. The audio playing subsystem according to claim 3, wherein the control unit further comprises an amplifier for amplifying the first echo and the second echo before the first echo and the second echo are received by the first inverter and the second inverter.
5. The audio playing subsystem according to claim 4, wherein the control unit further comprises a phase adjusting means for adjusting phases of the first echo and the second echo output by the amplifier.
6. The audio playing subsystem according to claim 3, wherein the first inverter comprises a first AD converter, a first digital signal processor and a first DA converter, the first AD converter is used for converting the first echo into a digital signal, the first digital signal processor is used for generating an antiphase signal of the first echo converted into the digital signal, and the first DA converter is used for converting the antiphase signal in the form of the digital signal into an analogue signal to generate the first antiphase signal.
7. The audio playing subsystem according to claim 3, wherein the second inverter comprises a second AD converter, a second digital signal processor and a second DA converter, the second AD converter is used for converting the second echo into a digital signal, the second digital signal processor is used for generating an antiphase signal of the second echo converted into the digital signal, and the second DA converter is used for converting the antiphase signal in the form of the digital signal into an analog signal to generate the second antiphase signal.
8. The audio playing subsystem according to claim 3, wherein the control unit further comprises a first post filter and a second post filter, the first post filter is used for smoothing the first antiphase signal output by the first inverter and sending it to the first synthesizer, and the second post filter is used for smoothing the second antiphase signal output by the second inverter and sending it to the second synthesizer.
9. The audio playing subsystem according to claim 1, wherein the first audio receiver and the second audio receiver also receive a noise with a fixed frequency, and the control unit compensates the left channel audio and the right channel audio according to the noise.
10. The audio playing subsystem according to claim 1, wherein the first audio receiver and the second audio receiver are microphones.
11. A mobile electronic device, comprising an audio playing subsystem, the audio playing subsystem including:
a first audio player and a second audio player disposed at the mobile electronic device symmetrically for playing a left channel audio and a right channel audio respectively;
a first audio receiver and a second audio receiver disposed at the mobile electronic device symmetrically for receiving a first echo of the left channel audio and a second echo of the right channel audio in real time respectively; and
a control unit for compensating the left channel audio and the right channel audio according to the first echo and the second echo which are received, and controlling the first audio player and the second audio player to play a compensated left channel audio and a compensated right channel audio respectively, wherein the compensated left channel audio and the compensated right channel audio are able to offset the first echo and the second echo respectively.
12. The mobile electronic device according to claim 11, wherein the control unit comprises a first filter and a second filter, the first filter takes an audio signal with the same frequency as the left channel audio and a smaller amplitude than the left channel audio as the first echo, and the second filter takes an audio signal with the same frequency as the right channel audio and a smaller amplitude than the right channel audio as the second echo.
13. The mobile electronic device according to claim 11, wherein the control unit comprises a first inverter, a first synthesizer, a second inverter and a second synthesizer, the first inverter receives the first echo and generates a first antiphase signal of the first echo, the first synthesizer synthesizes the first antiphase signal and the left channel audio into the compensated left channel audio, the second inverter receives the second echo and generates a second antiphase signal of the second echo, and the second synthesizer synthesizes the second antiphase signal and the right channel audio into the compensated right channel audio.
14. The mobile electronic device according to claim 13, wherein the control unit further comprises an amplifier for amplifying the first echo and the second echo before the first echo and the second echo are received by the first inverter and the second inverter.
15. The mobile electronic device according to claim 14, wherein the control unit further comprises a phase adjusting means for adjusting phases of the first echo and the second echo output by the amplifier.
16. The mobile electronic device according to claim 13, wherein the first inverter comprises a first AD converter, a first digital signal processor and a first DA converter, the first AD converter is used for converting the first echo into a digital signal, the first digital signal processor is used for generating an antiphase signal of the first echo converted into the digital signal, and the first DA converter is used for converting the antiphase signal in the form of the digital signal into an antilog signal to generate the first antiphase signal.
17. The mobile electronic device according to claim 13, wherein the second inverter comprises a second AD converter, a second digital signal processor and a second DA converter, the second AD converter is used for converting the second echo into a digital signal, the second digital signal processor is used for generating an antiphase signal of the second echo converted into the digital signal, and the second DA converter is used for converting the antiphase signal in the form of the digital signal into an analog signal to generate the second antiphase signal.
18. The mobile electronic device according to claim 13, wherein the control unit further comprises a first post filter and a second post filter, the first post filter is used for smoothing the first antiphase signal output by the first inverter and sending it to the first synthesizer, and the second post filter is used for smoothing the second antiphase signal output by the second inverter and sending it to the second synthesizer.
19. The mobile electronic device according to claim 11, wherein the first audio receiver and the second audio receiver further receive a noise with a fixed frequency, and the control unit compensates the left channel audio and the right channel audio according to the noise.
20. The mobile electronic device according to claim 11, wherein the first audio player and the second audio player are disposed symmetrically at a top and a bottom of the mobile electronic device respectively, and the first audio receiver and the second audio receiver are disposed symmetrically at the top and the bottom of the mobile electronic device.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An electromagnetic radiation-absorbing particle comprising:
(a) a core; and
(b) at least one shell,
wherein the shell encapsulates the core; and
wherein either the core or the shell comprises a conductive material, said material having a negative real part of the dielectric constant in a predetermined spectral band; and
wherein either
(i) the core comprises a first conductive material and the shell comprises a second conductive material different from the first conductive material; or
(ii) either the core or the shell comprises a refracting material.