The present disclosure relates to the technical field of the communication, and more particularly to a mobile communication terminal.
Currently, the 3G (3rd-Generation)/4G (4th-Generation) FDD (Frequency Division Duplexing) mobile terminals adopt a full duplex design, so that the transmitting path and the receiving path thereof can operate simultaneously. In the conventional FDD radio frequency (RF) architecture, the duplexer is a kind of indispensable device and mainly has following functions:
1) merging the transmitting path and the receiving path into a single path; and
2) filtering the transmitting path and the receiving path.
The duplexers currently available have a large insertion loss (IL), and especially when the duplexers operate in a high frequency band and the transmitting frequency and the receiving frequency are close to each other, the insertion loss is very large. For example, the duplexer used in WCDMA BC2 (Wideband Code Division Multiple Access BC2) has an insertion loss of above 2.5 dB. The main reason lies in that the transmitting frequency band is 1850 MHz˜1910 MHz and the receiving frequency band is 1930 MHz˜1990 MHz, and it is difficult to implement a band-pass filter that has a central frequency of 1950 MHz and a transition bandwidth of only 20 MHz.
Such the great insertion loss leads to the following problems:
1) the problem of great power consumption. In case of the large insertion loss, the output power of the amplifier must be increased to ensure sufficient output power, and this will necessarily increase the power consumption.
2) the problem of heat dissipation. As a result of the increased output power of the power amplifier and the increased power consumption, more heat will necessarily be generated. The heat generation amount of the power amplifiers in the conventional WCDMA terminals is very great, and this has an adverse effect on the battery and on the user experience.
3) the cost problem. Devices with high design specifications will necessarily have an increased cost.
As two signal receiving branches, the GSM980/850 RX SAW module 20 and the DCS/PCS RX SAW module 30 are configured to receive RF signals that are acquired by the receiving antenna 95 and strobed by the duplexer 90. The wireless transceiver 10 acquires RF signals processed by the GSM980/850 RX SAW module 20 via ports 1011 and 1012, and acquires RF signals processed by the DCS/PCS RX SAW module 30 via ports 1013 and 1014.
The GSM HB PA (GSM High Band Power Amplifier) 40 and the HB MN (High Band Match Network) 41 form one GSM signal transmitting branch. GSM high-band signals transmitted by the wireless transceiver 10 via a port 1015 are transmitted to the GSM HB PA 40 and the HB MN 41, and the GSM HB PA 40 and the HB MN 41 perform the power amplification process and the network matching process on the GSM high-band signals respectively. Then, the processed GSM high-band signals are strobed by the duplexer 90 and then transmitted by the antenna 95.
The GSM LB PA (GSM Low Band Power Amplifier) 50 and the LB MN (Low Band Match Network) 51 form another GSM signal transmitting branch. GSM low-band signals transmitted by the wireless transceiver 10 via a port 1016 are transmitted to the GSM LB PA 50 and the LB MN 51, and the GSM LB PA 50 and the LB MN 51 perform the power amplification process and the network matching process on the GSM low-band signals respectively. Then, the processed GSM low-band signals are strobed by the duplexer 90 and then transmitted by the antenna 95.
The WCDMA BC1 PA (WCDMA Band Class 1 Power Amplifier) 60, W MN1 (WCDMA match network) 61, the duplexer 62 and the DPX MN (Duplexer Match Network) 63 form one WCDMA signal transmitting/receiving branch which is configured to transmit or receive WCDMA BC1 signals. Specifically, BC1 signals are transmitted by the wireless transceiver 10 via a port 1021, and the WCDMA BC1 PA 60, the W MN1 61 and the DPX MN 63 perform the power amplification process and the network matching process on the BC1 signals respectively. Then, the processed BC1 signals are strobed by the duplexer 90 and then transmitted by the antenna 95. The duplexer 62 may be used for selecting a path so that the BC 1 signals transmitted by the wireless transceiver 10 via the port 1021 are transmitted to the outside via the antenna 95 or corresponding WCDMA signals are acquired from the antenna 95 via a port 1017.
Likewise, the wireless transceiver 10 generates WCDMA BC2 signals and WCDMA BC5 signals via a port 1022 and a port 1023 respectively, and acquires BC2 signals and BC 5 signals received by the antenna 95 from the outside via a port 1018 and a port 1019 respectively. Therefore, the port 1022 and the port 1023 correspond to two WCDMA signal transmitting branches respectively, and the port 1018 and the port 1019 correspond to two WCDMA signal receiving branches respectively. The WCDMA signal transmitting/receiving branches are completely same with the aforesaid WCDMA signal transmitting/receiving branches corresponding to the BC1 signals and thus, will not be further described herein.
Additionally, an RF connector 92 and an antenna match network (ANT MN) 94 are further disposed between the antenna and the duplexer 90, to couple signals from different signal sources and to perform the antenna matching process on the signals respectively.
In the conventional mobile communication terminal, the duplexer 90 is mainly used to:
1) merge the transmitting path and the receiving path into a single path; and
2) provide the isolation between the transmitting path and the receiving path, i.e., attenuate noises of the RF signals of the transmitting path in the receiving frequency band so as to prevent interfering with the received signal.
The reason of providing the isolation between the transmitting path and the receiving path is as follows: the receiving path is required to have a high sensitivity (the typical value is −110 dBm), and the transmitting path is a high-power path with a strength of up to 28 dBm. Because of the nonlinear nature of the RF system, there will necessarily be strong out-of-band stray signals when the main wave is 28 dBm. If these out-of-band stray signals are not isolated in the receiving frequency band but are directly fed into the receiving end, the strength thereof will exceed that of the useful receive signals and it will affect the receiving performance.
Next, the following will analyze the design of the WCDMA signal receiving system of the mobile communication terminal shown in
The typical receiving sensitivity of a conventional WCDMA terminal is −110 dBm.
The power of DPDCH (Dedicated Physical Data Channel) is −120.3 dBm.
The channel for WCDMA sensitivity testing has a coding rate of 12.2 kbps and a coding gain of 10×log(3.84 MHz/12.2)=25 dB.
The decoding threshold of the QPSK modulation scheme for WCDMA is 5.2 dB and a preset margin of 2 dB is required, so the input signal to noise ratio (SNR) of the demodulation module is required to be 7.2 dB.
Therefore, the noise at the input terminal of the demodulation module shall be lower than:
−120.3+25−7.2=−102.5 dBm/3.84 MHz=−168.343 dBm/Hz
Considering that the noise index of the wireless transceiver 10 is typically 5 dB, the noise at the input terminal of the demodulation module shall be lower than −173.343 dBm/Hz.
The system thermal noise is:
KBT=−200+26.022=−173.977 dBm/Hz=−108.13 dBm/3.84 MHz
where K (Boltzmann constant)=1.38×10−20 mJ/K, B=3.84 MHz (65.843 dB), T=290 K.
The output noise of the typical power amplifier (60, 70, 80) is:
−160 dBm/Hz(output of the wireless transceiver)+28 dB(typical amplification gain of the amplifier in the receiving frequency band)=−132 dBm/Hz=−66.16 dBm/3.84 MHz.
Therefore, an isolation degree of at least 173.343−132=41 dB needs to be provided by the duplexer 90.
Because such the great isolation degree is provided, the conventional duplexer has a relatively large insertion loss.
The conventional methods generally increase the power to decrease the insertion loss, but as the power increases, the power consumption of the system is increased and, correspondingly, the heat generation amount is relatively high.
Accordingly, there is a need to provide an antenna modulation method for a mobile communication terminal, to solve the aforesaid problems.
To solve the aforesaid technical problem, the present disclosure provides a mobile communication terminal to solve the technical problem that the insertion loss of the convention duplexer is relatively large.
To solve the aforesaid technical problem, a technical solution adopted by the present disclosure is to provide a mobile communication terminal. The mobile communication terminal comprises: a first antenna, being configured to receive a high-band radio frequency (RF) signal from the outside; a wireless transceiver, being configured to acquire the high-band RF signal from the first antenna and generate a first base-band signal according to the high-band RF signal; a base-band processor, being configured to acquire the first base-band signal from the wireless transceiver and modulate the first base-band signal, and further generate a second base-band signal and a third base-band signal for transmission to the wireless transceiver; the wireless transceiver being further configured to convert the second base-band signal into a to-be-transmitted high-band RF signal and convert the third base-band signal into a to-be-transmitted low-band RF signal; a second antenna, being configured to acquire from the wireless transceiver and transmit the to-be-transmitted high-band RF signal and the to-be-transmitted low-band RF signal; wherein the second antenna is further configured to receive a low-band RF signal from the outside, the wireless transceiver is configured to acquire the low-band RF signal from the second antenna and generate a fourth base-band signal according to the low-band RF signal, and the base-band processor is configured to acquire the fourth base-band signal from the wireless transceiver and modulate the fourth base-band signal; a high-band RF signal power amplifier, being disposed between the second antenna and the wireless transceiver and configured to amplify the power of the to-be-transmitted high-band RF signal generated by the wireless transceiver; and a low-band RF signal power amplifier, being disposed between the second antenna and the wireless transceiver and configured to amplify the power of the to-be-transmitted low-band RF signal generated by the wireless transceiver.
Preferably, the high-band RF signal comprises a BC1 signal and a BC4 signal, the low-band RF signal comprises a GSM HB signal and a GSM LB signal, the to-be-transmitted high-band RF signal comprises a BC1/BC4 signal and a BC2 signal, and the to-be-transmitted low-band RF signal comprises a to-be-transmitted GSM HB signal, a to-be-transmitted GSM LB signal and a to-be-transmitted BC5/BC8 signal.
Preferably, the mobile communication terminal further comprises: a high-band RF signal reception surface acoustic wave (SAW) filter, being disposed between the first antenna and the wireless transceiver and configured to perform a reception SAW filtering process on the high-band RF signal received by the first antenna; and a low-band RF signal reception SAW filter, being disposed between the second antenna and the wireless transceiver and configured to perform the reception SAW filtering process on the low-band RF signal received by the second antenna.
To solve the aforesaid technical problem, another technical solution adopted by the present disclosure is to provide a mobile communication terminal. The mobile communication terminal comprises: a first antenna, being configured to receive a high-band radio frequency (RF) signal from the outside; a wireless transceiver, being configured to acquire the high-band RF signal from the first antenna and generate a first base-band signal according to the high-band RF signal; a base-band processor, being configured to acquire the first base-band signal from the wireless transceiver and modulate the first base-band signal, and further generate a second base-band signal and a third base-band signal for transmission to the wireless transceiver; the wireless transceiver being further configured to convert the second base-band signal into a to-be-transmitted high-band RF signal and convert the third base-band signal into a to-be-transmitted low-band RF signal; a second antenna, being configured to acquire from the wireless transceiver and transmit the to-be-transmitted high-band RF signal and the to-be-transmitted low-band RF signal; wherein the second antenna is further configured to receive a low-band RF signal from the outside, the wireless transceiver is configured to acquire the low-band RF signal from the second antenna and generate a fourth base-band signal according to the low-band RF signal, and the base-band processor is configured to acquire the fourth base-band signal from the wireless transceiver and modulate the fourth base-band signal.
Preferably, the high-band RF signal comprises a BC1 signal and a BC4 signal, the low-band RF signal comprises a GSM HB signal and a GSM LB signal, the to-be-transmitted high-band RF signal comprises a BC1/BC4 signal and a BC2 signal, and the to-be-transmitted low-band RF signal comprises a to-be-transmitted GSM HB signal, a to-be-transmitted GSM LB signal and a to-be-transmitted BC5/BC8 signal.
Preferably, the mobile communication terminal further comprises: a high-band RF signal reception surface acoustic wave (SAW) filter, being disposed between the first antenna and the wireless transceiver and configured to perform a reception SAW filtering process on the high-band RF signal received by the first antenna; and a low-band RF signal reception SAW filter, being disposed between the second antenna and the wireless transceiver and configured to perform the reception SAW filtering process on the low-band RF signal received by the second antenna.
Preferably, the mobile communication terminal further comprises: a high-band RF signal power amplifier, being disposed between the second antenna and the wireless transceiver and configured to amplify the power of the to-be-transmitted high-band RF signal generated by the wireless transceiver.
Preferably, the mobile communication terminal further comprises: a low-band RF signal power amplifier, being disposed between the second antenna and the wireless transceiver and configured to amplify the power of the to-be-transmitted low-band RF signal generated by the wireless transceiver.
To solve the aforesaid technical problem, yet another technical solution adopted by the present disclosure is to provide a mobile communication terminal. The mobile communication terminal comprises: a first antenna, being configured to receive a high-band radio frequency (RF) signal and a low-band RF signal from the outside; a wireless transceiver, being configured to acquire the high-band RF signal from the first antenna and generate a first base-band signal according to the high-band RF signal, and being configured to acquire the low-band RF signal from the first antenna and generate a second base-band signal according to the low-band RF signal; a base-band processor, being configured to acquire the first base-band signal and the second base-band signal from the wireless transceiver and modulate the first base-band signal and the second base-band signal, and further generate a third base-band signal and a fourth base-band signal for transmission to the wireless transceiver; the wireless transceiver being further configured to convert the third base-band signal into a to-be-transmitted high-band RF signal and convert the fourth base-band signal into a to-be-transmitted low-band RF signal; a second antenna, being configured to acquire from the wireless transceiver and transmit the to-be-transmitted high-band RF signal; wherein the first antenna is further configured to acquire from the wireless transceiver and transmit the to-be-transmitted low-band RF signal.
Preferably, the high-band RF signal comprises a BC1/BC4 signal, the low-band RF signal comprises a GSM 900/850 signal, a GSM DCS signal and a BC5/BC8 signal, the to-be-transmitted high-band RF signal comprises a BC1/BC4 signal and a BC2 signal, and the to-be-transmitted low-band RF signal comprises a to-be-transmitted GSM HB signal, a to-be-transmitted GSM LB signal and a to-be-transmitted BC5/BC8 signal.
Preferably, the mobile communication terminal further comprises: a high-band RF signal reception surface acoustic wave (SAW) filter, being disposed between the first antenna and the wireless transceiver and configured to perform a reception SAW filtering process on the high-band RF signal received by the first antenna; and a low-band RF signal reception SAW filter, being disposed between the first antenna and the wireless transceiver and configured to perform the reception SAW filtering process on the low-band RF signal received by the first antenna.
Preferably, the mobile communication terminal further comprises: a high-band RF signal power amplifier, being disposed between the second antenna and the wireless transceiver and configured to amplify the power of the to-be-transmitted high-band RF signal generated by the wireless transceiver.
Preferably, the mobile communication terminal further comprises: a low-band RF signal power amplifier, being disposed between the first antenna and the wireless transceiver and configured to amplify the power of the to-be-transmitted low-band RF signal generated by the wireless transceiver.
As compared to the prior art, the benefits of the present disclosure are as follows: the technical solution provided by the present disclosure disposes a first antenna and a second antenna, enables the first antenna to receive a high-band RF signal from the outside, enables the second antenna to transmit a to-be-transmitted high-band RF signal and a to-be-transmitted low-band RF signal, and enables the second antenna to receive a low-band RF signal. Accordingly, a high-frequency duplexer is omitted, so the insertion loss problem caused by the high-frequency duplexer is solved and, correspondingly, noises caused in the receiving frequency band by the transmitting path is reduced; and furthermore, the power consumption and the heat generation amount of the system are further decreased. Meanwhile, the radio frequency (RF) architecture is simplified, and a low-cost and more compact space can be obtained. The present disclosure is especially suitable for a platform having a relatively low output power.
Referring to
In a preferred embodiment, the high-band RF signal comprises a BC1 signal and a BC4 signal, the low-band RF signal comprises a GSM HB signal and a GSM LB signal, the to-be-transmitted high-band RF signal comprises a BC1/BC4 signal and a BC2 signal, and the to-be-transmitted low-band RF signal comprises a to-be-transmitted GSM HB signal, a to-be-transmitted GSM LB signal and a to-be-transmitted BC5/BC8 signal.
In a preferred embodiment, the mobile communication terminal 100 further comprises a high-band RF signal reception surface acoustic wave (SAW) filter and a low-band RF signal reception SAW filter. The high-band RF signal reception SAW filter is disposed between the first antenna 101 and the wireless transceiver 102, and configured to perform a reception SAW filtering process on the high-band RF signal received by the first antenna 101. The low-band RF signal reception SAW filter is disposed between the second antenna 104 and the wireless transceiver 102 and configured to perform the reception SAW filtering process on the low-band RF signal received by the second antenna 104.
In a preferred embodiment, the mobile communication terminal 100 further comprises a high-band RF signal power amplifier and a low-band RF signal power amplifier. The high-band RF signal power amplifier is disposed between the second antenna 104 and the wireless transceiver 102 and configured to amplify the power of the to-be-transmitted high-band RF signal generated by the wireless transceiver 102. The low-band RF signal power amplifier is disposed between the second antenna 104 and the wireless transceiver 102 and configured to amplify the power of the to-be-transmitted low-band RF signal generated by the wireless transceiver 102.
Please refer to
Referring to
Likewise, the transceiving principle of the second high-band RF signal is the same as that of the first high-band RF signal, and the architectures of the transceiving paths of the second high-band RF signal and the first high-band RF signal are completely same. Differences lie in that: the wireless transceiver 402 is configured to receive the second high-band RF signal output by a second high-band RF signal reception SAW filter 412 from a port 4024, and output the corresponding second to-be-transmitted high-band RF signal via a port 4027 after the second high-band RF signal is converted by the base-band processor; and a second high-band RF signal transmitting filter 420 and a second high-band RF signal power amplifier 417 filter and amplify the second to-be-transmitted high-band RF signal respectively.
In a preferred embodiment, the second antenna 401 is further configured to receive a low-band RF signal from the outside. The second antenna 401, the second control switch 405, a first low-band RF signal reception SAW filter 410, the wireless transceiver 402 and a first low-band RF signal power amplifier 409 form the transceiving path of the first low-band RF signal which is configured to receive and transmit the first low-band RF signal. In detail, the second antenna 401 is configured to receive a first low-band RF signal from the outside, and transmit the first low-band RF signal to the first low-band RF signal reception SAW filter 410 for filtering after being strobed by the second control switch 405. The transceiver 402 is configured to receive the filtered first low-band RF signal from a port 4021, generate a fourth base-band signal according to the first low-band RF signal and output the fourth base-band signal to the base-band processor (not shown). The base-band processor is configured to acquire the fourth base-band signal output from the wireless transceiver 402 and modulate the fourth base-band signal. The wireless transceiver 402 is further configured to convert the signal modulated by the base-band processor into a first to-be-transmitted low-band RF signal and transmit the first to-be-transmitted low-band RF signal via a port 4030. The first to-be-transmitted low-band RF signal is amplified by the first low-band RF signal power amplifier 409 and then transmitted by the second antenna 401 after being strobed by the second antenna 405.
Likewise, the transceiving principle of the second low-band RF signal is the same as that of the first low-band RF signal, and the architectures of the transceiving paths of the second low-band RF signal and the first low-band RF signal are completely same. Differences lie in that: the wireless transceiver 402 is configured to receive the second low-band RF signal output by a second low-band RF signal reception SAW filter 411 from a port 4023, and output the corresponding second to-be-transmitted low-band RF signal via a port 4029 after the second low-band RF signal is converted by the base-band processor; and then the second to-be-transmitted low-band RF signal is amplified by a second low-band RF signal power amplifier 408.
In a preferred embodiment, the first high-band RF signal and the second high-band RF signal comprise a BC1 signal and a BC4 signal, the first low-band RF signal and the second low-band RF signal comprise a GSM LB signal and a GSM HBG signal, the first to-be-transmitted high-band RF signal and the second to-be-transmitted high-band RF signal comprise a BC1/BC4 signal and a BC2 signal, and the first to-be-transmitted low-band RF signal, the second to-be-transmitted low-band RF signal and the third to-be-transmitted low-band RF signal comprise a GSM HB signal, a to-be-transmitted GSM LB signal and a to-be-transmitted BC5/BC8 signal.
Referring to
In this embodiment, the first antenna 301 is configured to receive a high-band RF signal from the outside. In detail, when a fixed terminal 3054 of the control switch 305 is connected with a port 3051, the wireless transceiver 302 acquires the high-band RF signal received by the first antenna 301 from a port 3025. The wireless transceiver 302 is configured to generate a first base-band signal according to the high-band RF signal and output the first base-band signal from a port 3021 to the base-band processor 303. The base-band processor 303 is configured to acquire the first base-band signal output from the port 3021 via a port 3031 and modulate the first base-band signal, and further generate a third base-band signal so as to transmit the third base-band signal from a port 3034 to the wireless transceiver 302. The wireless transceiver 302 is configured to receive the third base-band signal output from the port 3034 via a port 3024, further convert the third base-band signal into a to-be-transmitted high-band RF signal, and output the to-be-transmitted high-band RF signal to the second antenna 304 via a port 3028. The second antenna 304 is configured to transmit the to-be-transmitted high-band RF signal.
In this embodiment, the first antenna 301 is further configured to receive a low-band RF signal from the outside and transmit a to-be-transmitted low-band RF signal. In detail, when the fixed terminal 3054 of the control switch 305 is connected with a port 3052, the wireless transceiver 302 acquires the low-band RF signal received by the first antenna 301 from a port 3026. The wireless transceiver 302 is configured to generate a second base-band signal according to the low-band RF signal and output the second base-band signal from a port 3022 to the base-band processor 303. The base-band processor 303 is configured to acquire the second base-band signal output from the port 3022 via a port 3032 and modulate the second base-band signal, and further generate a fourth base-band signal so as to transmit the fourth base-band signal from a port 3033 to the wireless transceiver 302. The wireless transceiver 302 is configured to receive the fourth base-band signal output from the port 3033 via a port 3023, further convert the fourth base-band signal into a to-be-transmitted low-band RF signal, and output the to-be-transmitted low-band RF signal to the first antenna 301 via a port 3027 when the fixed terminal 3054 of the control switch 305 is connected with a port 3053. The first antenna 301 is configured to transmit the to-be-transmitted low-band RF signal.
In a preferred embodiment, the high-band RF signal comprises a BC1/BC4 signal, the low-band RF signal comprises a GSM 900/850 signal, a GSM DCS signal and a BC5/BC8 signal, the to-be-transmitted high-band RF signal comprises a BC1/BC4 signal and a BC2 signal, and the to-be-transmitted low-band RF signal comprises a to-be-transmitted GSM HB signal, a to-be-transmitted GSM LB signal and a to-be-transmitted BC5/BC8 signal.
In a preferred embodiment, the mobile communication terminal 300 further comprises a high-band RF signal reception surface acoustic wave (SAW) filter and a low-band RF signal reception SAW filter. The high-band RF signal reception SAW filter is disposed between the first antenna 301 and the wireless transceiver 302 and configured to perform a reception SAW filtering process on the high-band RF signal received by the first antenna 301. The low-band RF signal reception SAW filter is disposed between the first antenna 301 and the wireless transceiver 302 and configured to perform the reception SAW filtering process on the low-band RF signal received by the first antenna 301.
In a preferred embodiment, the mobile communication terminal 300 further comprises a high-band RF signal power amplifier and a low-band RF signal power amplifier. The high-band RF signal power amplifier is disposed between the second antenna 304 and the wireless transceiver 302 and configured to amplify the power of the to-be-transmitted high-band RF signal generated by the wireless transceiver 302. The low-band RF signal power amplifier is disposed between the first antenna 301 and the wireless transceiver 302 and configured to amplify the power of the to-be-transmitted low-band RF signal generated by the wireless transceiver 302.
Please refer to
Referring to
Likewise, the transceiving principle of the second high-band RF signal is the same as that of the first high-band RF signal, and the architectures of the transceiving paths of the second high-band RF signal and the first high-band RF signal are completely the same. Differences lie in that: the wireless transceiver 202 is configured to receive the second high-band RF signal output by a second high-band RF signal reception SAW filter 213 via a port 2025, and output the corresponding second to-be-transmitted high-band RF signal via a port 2026 after the second high-band RF signal is converted by the base-band processor; and the second to-be-transmitted high-band RF signal is filtered and amplified by a second high-band RF signal transmitting filter 219 and a second high-band RF signal power amplifier 216 respectively.
In a preferred embodiment, the first antenna 201 is further configured to acquire from the wireless transceiver 202 and transmit the to-be-transmitted low-band RF signal. The low-band RF signals have three transceiving paths. The first antenna 201, the first control switch 205, a first low-band RF signal reception SAW filter 210, the wireless transceiver 202, and a first low-band RF signal power amplifier 209 form the transceiving path of the first low-band RF signal which is configured to receive and transmit the first low-band RF signal. Specifically, the first antenna 201 is configured to receive a first low-band RF signal from the outside, and transmit the first low-band RF signal to the first low-band RF signal reception SAW filter 210 for filtering after being strobed via the first control switch 205. The transceiver 202 is configured to receive the filtered first low-band RF signal from a port 2021, generate a second base-band signal according to the first low-band RF signal and output the second base-band signal to the base-band processor (not shown). The base-band processor is configured to acquire the second base-band signal output by the wireless transceiver 202 and modulate the second base-band signal, and further generate a fourth base-band signal. The wireless transceiver 202 is further configured to convert the fourth base-band signal into a first to-be-transmitted low-band RF signal, and transmit the first to-be-transmitted low-band RF signal via a port 2030. The first to-be-transmitted low-band RF signal is amplified by the first low-band RF signal power amplifier 209 and then transmitted by the first antenna 201 after being strobed by the first control switch 205.
Likewise, the transceiving principle of the second low-band RF signal is the same as that of the first low-band RF signal, and the architectures of the transceiving paths of the second low-band RF signal and the first low-band RF signal are completely the same. Differences lie in that: the wireless transceiver 202 is configured to receive the second low-band RF signal output by a second low-band RF signal reception SAW filter 211 via a port 2023, and output the corresponding second to-be-transmitted low-band RF signal via a port 2029 after the second low-band RF signal is converted by the base-band processor; and then the second to-be-transmitted low-band RF signal is amplified by a second low-band RF signal power amplifier 208.
In a preferred embodiment, the first antenna 201, the first control switch 205, the wireless transceiver 202, a duplexer 215, and a third low-band RF signal power amplifier 218 form the transceiving path of a third low-band RF signal. The duplexer 215 is configured to select a path so that after strobing of the first control switch 205, the wireless transceiver 202 can receive the third low-band RF signal, which is acquired from the first antenna 201, from the duplexer 215 via a port 2022 and transmit the third low-band RF signal to the base-band processor for modulation. The third low-band RF signal is further converted into a third to-be-transmitted low-band RF signal by the wireless transceiver 202, and transmitted via a port 2028 to the third low-band RF signal power amplifier 218 for amplification. After being strobed by the first control switch 205, the third to-be-transmitted low-band RF signal is transmitted to the first antenna 201 via the duplexer 215, and then transmitted to the outside by the first antenna 201.
In a preferred embodiment, the first high-band RF signal and the second high-band RF signal comprise a BC1/BC4 signal; the first low-band RF signal, the second low-band RF signal and the third low-band RF signal comprise a GSM 900/850 signal, a GSM DCS signal and a BC5/BC8 signal; the first to-be-transmitted high-band RF signal and the second to-be-transmitted high-band RF signal comprise a BC1/BC4 signal and a BC2 signal; and the first to-be-transmitted low-band RF signal, the second to-be-transmitted low-band RF signal, and the third to-be-transmitted low-band RF signal comprise a to-be-transmitted GSM HB signal, a to-be-transmitted GSM LB signal and a to-be-transmitted BC5/BC8 signal.
In the present disclosure, the high-band receiving antenna is used for 3G/4G high-band receiving. Generally, the main antenna is disposed right at the back of the mobile phone. According to the circuit diagram illustrating the operating principle of the RF signal transceiving circuit of the mobile communication terminal as shown in FIG. 1, the 3G/4G high-frequency transmitting antenna must be located at the front of the mobile phone to provide a sufficient isolation degree. However, this would result in excessively high SAR (Specific Absorption Rate) and HAC (Hearing Auxiliary Compatibility).
In
The present disclosure further measures the receiving interference immunity of the mobile communication terminal, and the measurement result is as shown in Table 2:
As can be known from Table 2, if there is a high isolation degree between the transmitting antenna and the receiving antenna, that is, no additive white Gaussian noise (AWGN) is in the channel, the sensitivity of the high-, mid-, and low-channels are −109.5, −110, and −109.5 respectively.
If the isolation degree between the antennas is up to 27 dB, the sensitivity of the high-, mid-, and low-channels are −107.5, −109, and −109 respectively under the noise condition of the power amplifier shown in Table 1.
If the isolation degree between the antennas is up to 27 dB, the sensitivity of the high-, mid-, and low-channels are −105, −107.5, and −107.5 respectively under the noise condition of the power amplifier shown in Table 1. That is, the sensitivity thereof decreases by 4.5 dB, 2.5 dB and 2.5 dB respectively.
In light of the aforesaid experiment, the present disclosure carried out an experiment on the isolation degree between antennas. That is, a first antenna as shown in
Referring to
As can be seen, an improvement in current of 140 mA at most can be obtained by the antenna architecture of the mobile communication terminal proposed by the present disclosure.
According to the above descriptions, the technical solution provided by the present disclosure disposes a first antenna and a second antenna, enables the first antenna to receive a high-band RF signal from the outside, enables the second antenna to transmit a to-be-transmitted high-band RF signal and a to-be-transmitted low-band RF signal, and enables the second antenna to receive the low-band RF signal. Accordingly, use of a high-frequency duplexer is omitted, so the insertion loss problem caused by the high-frequency duplexer is solved and, correspondingly, noises caused in the receiving frequency band by the transmitting path is reduced; and furthermore, the power consumption and the heat generation amount of the system are further decreased. Meanwhile, the radio frequency (RF) architecture is simplified, and a low-cost and more compact space can be obtained. The present disclosure is especially suitable for a platform having relatively low output power.
What described above are only the embodiments of the present disclosure, but are not intended to limit the scope of the present disclosure. Any equivalent structures or equivalent process flow modifications that are made according to the specification and the attached drawings of the present disclosure, or any direct or indirect applications of the present disclosure in other related technical fields shall all be covered within the scope of the present disclosure.
Number | Date | Country | Kind |
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201210134523.6 | May 2012 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2013/072239 | 3/6/2013 | WO | 00 |