The invention discloses a radio frequency front-end based on the high-intermediate frequency superheterodyne and zero intermediate frequency structure, which includes a transmitting module and a receiving module, wherein, the receiving module includes the following devices connected in turn with each other: a transceiving antenna, a low-pass filter, a superheterodyne unit, an IF band-pass filter, a zero-IF unit, a analog-to-digital converter and a digital baseband module of which the output is communicated with the transmitting module. The zero-IF unit includes the following devices which are also connected in turn with each other: a zero-IF mixer, an active low-pass filter and a variable gain operational amplifier of which the output is communicated with the input of the ADC; the inputs of the zero-IF mixer are communicated with the output of the IF band-pass filter and the second LO respectively. The present invention avoids the image interference, improves the system integration and decreases the system consumption.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A radio frequency (RF) front-end based on a high-intermediate frequency superheterodyne and zero intermediate frequency (zero-IF) structure comprising a transmitting module and a receiving module, said receiving module comprising: a transceiving antenna ( 1 ), a low-pass filter ( 3 ) connected to said transceiving antenner, a superheterodyne unit ( 4 ) connected to said low-pass filter, an IF band-pass filter ( 5 ) connected to said superheterodyne unit, a zero-IF unit ( 6 ) connected to said IF band-pass filter, a analog-to-digital converter (ADC) ( 7 ) connected to said zero-IF unit and a digital baseband (DBB) module ( 8 ) connected to said analog-to-digital converter at one end and connected to said transmitting module ( 9 ) at another end, wherein said superheterodyne unit having a first local oscillator ( 43 ) and said transmitting module having a third local oscillator ( 94 ).
2. The radio frequency front-end according to the claim 1 , wherein the transceiving antenna ( 1 ) communicates with the low-pass filter ( 3 ) by wireless switch ( 2 ).
3. The radio frequency front-end according to the claim 1 , wherein the superheterodyne unit ( 4 ) comprises a superheterodyne mixer ( 42 ), the inputs of which are communicated with a low noise amplifier (LNA) ( 41 ) and the first local oscillator (LO) ( 43 ) respectively; and the output of the superheterodyne mixer ( 42 ) is communicated with the input of the IF band-pass filter ( 5 ); wherein, the input of the LNA ( 41 ) is communicated with the output of the low-pass filter ( 3 ).
4. The radio frequency front-end according to the claim 3 , wherein the tuning range of the first LO ( 43 ) ranges from 1.25 GHz to 2.35 GHz.
5. The radio frequency front-end according to the claim 1 , wherein the zero-IF unit ( 6 ) comprises the following devices which are connected with each other in turn: a zero-IF mixer ( 61 ), an active low-pass filter ( 63 ) and a variable gain operational amplifier ( 64 ) of which an output is communicated with the input of the ADC ( 7 ); the inputs of the zero-IF mixer ( 61 ) are communicated with the output of the IF band-pass filter ( 5 ) and a second LO ( 62 ).
6. The radio frequency front-end according to the claim 1 , wherein the transmitting module ( 9 ) comprises the follows which are connected with each other in turn: a modulation mixer ( 91 ), a power amplifier (PA) driving circuit ( 92 ) and a power amplifier ( 93 ); the inputs of the modulation mixer ( 91 ) are communicated with the output of the DBB module ( 8 ) and the third LO ( 94 ); and the output of the power amplifier ( 93 ) is communicated with the wireless switch ( 2 ) of the transceiving antenna ( 1 ).
7. The radio frequency front-end according to the claim 1 , wherein the output of the superheterodyne unit ( 4 ) has a fixed-frequency of 2.45 GHz.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
September 12, 2012
February 23, 2016
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