WO2012100455A1

WO2012100455A1 - Method and apparatus for implementing frequency modulation antenna, and mobile terminal

Info

Publication number: WO2012100455A1
Application number: PCT/CN2011/072047
Authority: WO
Inventors: 何文卿; 何经纬
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-01-27
Filing date: 2011-03-22
Publication date: 2012-08-02
Also published as: CN102098069A

Abstract

Provided is an apparatus for implementing frequency modulation (FM) antenna. The apparatus comprises a communication main antenna, an antenna multiplexer connected with the communication main antenna and an FM reception chip connected with the antenna multiplexer. Wherein the communication main antenna is set to receive mobile network signals or FM signals; the antenna multiplexer is set to control the communication main antenna switching to receive mobile network signals or FM signals and to filter the received FM signals when the communication main antenna receives the FM signals; the FM reception chip is set to receive the filtered FM signals output from the antenna multiplexer and send the FM signals to the audio output unit for playing. The present invention discloses a method for implementing FM antenna and a mobile terminal. The present invention avoids the problem that in the case of dual-antenna design, the antenna performances of some antennas are deteriorated due to lack of fairly good circumstances.

Description

FM antenna implementation method, device and mobile terminal

The present invention relates to the field of mobile communications, and in particular, to a method, an apparatus, and a mobile terminal for implementing a frequency modulation antenna.

BACKGROUND OF THE INVENTION It is common to implement a Frequency Modulation (FM) function in a mobile terminal. In the prior art, FM signals are typically received by way of headphones acting as FM receive antennas. In addition, the prior art also has an FM signal received by designing a separate FM antenna. The above two schemes are currently the most common solution for designing FM-enabled mobile terminals. However, the above-mentioned way of acting as an FM receiving antenna through the earphone cannot realize the FM external discharging function. In the above manner, by designing an independent FM antenna to receive an FM signal, the mobile terminal must have a main antenna and an FM antenna to ensure normal application of the basic wireless call function and normal reception of the FM function. Figure 1 shows the implementation of the more common mobile phone FM internal antenna. The FM receiving chip is used on the mobile phone to process the FM signal after receiving, and the FM receiving chip is connected to the front end of the built-in antenna for FM receiving through the transmission line. In this way, two antennas will be included in the whole system. Due to the low frequency of FM, such antennas are generally large, which is more demanding on the space of the mobile terminal and the environment of the internal antenna. This is one of the shortcomings of current mobile phones with FM external functions. Another disadvantage is that two antennas are implemented on one mobile terminal, which is not only complicated in design, but also has crosstalk between the two antennas, so that the receiving sensitivities of the two antennas of the mobile terminal are reduced to different degrees. In addition, with the miniaturization of mobile terminals, there are fewer and fewer environments suitable for antenna design on mobile terminals. The two antenna design environments of mobile terminals cannot ensure that the performance of each antenna is theoretically guaranteed. Therefore, the constraints of the antenna design environment must also be faced at design time.

SUMMARY OF THE INVENTION The technical problem to be solved by the present invention is to provide a method, a device, and a mobile terminal for implementing a frequency modulation antenna. At the end, avoid the problem of the prior art that only plug-in headphones can listen to FM or need to design an FM antenna separately to listen to FM. In order to solve the above technical problem, the present invention provides a frequency modulation antenna implementing apparatus, the apparatus comprising: a communication main antenna, an antenna multiplexing device connected to the communication main antenna, and an FM receiving chip connected to the antenna multiplexing device, wherein: The communication main antenna is configured to: receive a mobile network signal or a frequency modulation signal; the antenna multiplexing device is configured to: control the communication main antenna to switch to receive a mobile network signal or a frequency modulation signal, and when the communication main antenna receives the frequency modulation signal, The received FM signal is filtered; the FM receiving chip is configured to: receive the filtered FM signal output by the antenna multiplexing device, and send the FM signal to an audio output unit for playing. The antenna multiplexing device includes a signal switching unit and a matching circuit, where: the signal switching unit is configured to: be connected to the communication main antenna, and output a mobile network signal or a frequency modulation signal;

The matching circuit is connected to the signal switching unit, and the matching circuit is configured to: filter the FM signal output by the signal switching unit, and output the filtered FM signal to the FM receiving chip. among them:

The signal switching unit is an antenna switch, and the signal switching unit is configured to output a mobile network signal or a frequency modulation signal according to the following manner: controlling reception of the communication main antenna according to current transmission and reception conditions of the mobile network signal, and outputting a mobile network signal or FM signal. Wherein: the terminal of the signal switching unit outputting the mobile network signal comprises an output terminal of the first signal and an output terminal of the second signal; an input of the matching circuit is multiplexed with the first signal, an output terminal, or The second signal is multiplexed with one output terminal. among them:

The input of the matching circuit independently occupies one output terminal of the antenna switch. Wherein: the signal switching unit is a duplexer.

Wherein: an input of the matching circuit and an output terminal of the duplexer are multiplexed with the mobile network signal. among them:

The matching circuit includes an inductor L1, one end of the L1 is connected to an output of the signal switching unit, and the other end is connected to an input of the FM chip, and the value range of the L1 is

[100nH, 1000nH]. among them:

The value of L1 is 200nH. among them:

The matching circuit includes: a first inductor L1 and a second inductor L2, one end of the L1 is connected to an output of the signal switching unit, and the other end is connected to an input of the FM chip, and one end of the L2 is L1 is connected to one end connected to the FM chip, and the other end is grounded; the value range of L1 is [ΙΟΟηΗ, ΙΟΟΟηΗ], and the range of L2 is [47ηΗ, 270ηΗ]. among them:

The value of L1 is 200ηΗ, and the value of L2 is 68ηΗ. among them:

The audio output unit is a speaker. Wherein: the signal switching unit is configured to control reception of the communication main antenna according to a current transmission and reception condition of the mobile network signal in the following manner: When it is required to transmit or receive a mobile network signal, the signal switching unit controls the communication main antenna to receive a mobile network signal; when the signal switching unit is in a non-receiving or non-transmitting mobile network signal state, and needs to receive a frequency modulated signal, The signal switching unit controls the communication main antenna to receive a frequency modulation signal. In order to solve the above technical problem, the present invention further provides a mobile terminal, where the terminal includes: the above-mentioned FM antenna implementing device. In order to solve the above technical problem, the present invention further provides a method for implementing a frequency modulation antenna, the method comprising: after the frequency modulation function is turned on, if it is determined that the mobile terminal is communicating with the base station, continuing the process of communicating with the base station, if it is determined that the mobile terminal is to be In communication with the base station, the communication main antenna is controlled to receive the mobile network signal, and if it is determined that the mobile terminal is neither in a state of communicating with the base station nor in a state to be in communication with the base station, the communication main antenna is controlled to receive the FM signal. The method further includes: after exiting the frequency modulation function, controlling the communication main antenna to be in a state of not receiving a signal.

The method, device and system of the embodiments of the present invention can multiplex the mobile service main antenna and the FM antenna, and can listen to the FM without inserting the earphone, and also avoid the dual antenna design, some antennas are not good enough. The environment causes a drop in antenna performance, reducing the space left by the mobile terminal for the design of the main antenna and the FM antenna. Additionally, the methods, apparatus, and systems of the present invention do not result in degradation of antenna performance.

1 is a schematic diagram of a system for a mobile terminal using a separate FM antenna; FIG. 2 is a schematic structural diagram of an FM receiving system according to Embodiment 1 of the present invention; FIG. 3 is a system for implementing a mobile terminal for FM using a GSM main antenna according to Embodiment 2 of the present invention; schematic diagram; 4 is a schematic diagram of an FM matching circuit in Embodiment 2; FIG. 5 is a schematic diagram of a system for implementing a mobile terminal using FM as a GSM main antenna according to Embodiment 3 of the present invention;

6 is a flow chart of implementing FM by using a GSM main antenna according to Embodiment 4 of the present invention; and FIG. 7 is a schematic diagram of a system for implementing a mobile terminal of FM using a CDMA/WCDMA main antenna according to Embodiment 5 of the present invention.

Preferred embodiment of the invention

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other. Embodiment 1 The FM receiving apparatus of this embodiment includes: a communication main antenna, an antenna multiplexing device connected to the communication main antenna, and an FM receiving chip connected to the antenna multiplexing device, wherein: the communication main antenna is set as: receiving the mobile network a signal or frequency modulation signal; the antenna multiplexing device is configured to: control the communication main antenna to switch to receive a mobile network signal or a frequency modulation signal, and filter the received frequency modulation signal when the communication main antenna receives the frequency modulation signal; FM receiving chip setting The method is: receiving the filtered FM signal output by the antenna multiplexing device, and sending the filtered FM signal to the audio output unit for playing.

As shown in FIG. 2, the antenna multiplexing device includes a signal switching unit and a matching circuit, wherein: the signal switching unit is configured to: be connected to the communication main antenna, and output a mobile network signal or a frequency modulation signal;

The matching circuit is connected to the signal switching unit, and the matching circuit is configured to: filter the FM signal output by the signal switching unit, and output the filtered FM signal to the FM receiving chip. The above audio output unit is preferably a speaker (or a speaker), and may be a built-in speaker, It can be an external speaker (such as a speaker), which can highlight the effect of the multiplex antenna of the present invention. However, it is not excluded to use the headphones to play. The signal switching unit may be an antenna switch. For example, the mobile terminal using the antenna multiplexing device is a time-division mobile terminal, for example, a Global System for Mobile Communications (GSM) or a Time Division Synchronous Code Division Multiple Access ( Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) mobile terminal. At this time, the signal switching unit outputs the mobile network signal or the FM signal in the following manner: The signal switching unit controls the reception of the communication main antenna according to the current transmission and reception condition of the mobile network signal, and outputs a mobile network signal or a frequency modulation signal. The signal switching unit may also be a duplexer. For example, the mobile terminal using the antenna multiplexing device is a non-time-division mobile terminal, for example, a code division multiple access (CDMA) system or a wideband code. (Wideband Code Division Multiple Access, WCDMA) system standard mobile terminal. When the signal switching unit is an antenna switch, the terminal of the signal switching unit outputting the mobile network signal includes an output terminal of the first signal (for example, GSM900) and an output terminal of the second signal (for example, GSM1800); the input of the matching circuit and the first signal are An output terminal is used, or an output terminal is multiplexed with the second signal. Alternatively, the input of the matching circuit independently occupies one output terminal of the antenna switch. When the signal switching unit is a duplexer, the input of the matching circuit and the mobile network signal are multiplexed with one output terminal of the duplexer. The matching circuit includes an inductor L1. One end of the L1 is connected to the output of the signal switching unit, and the other end is connected to the input of the FM chip. The value of the inductor ranges from [100nH, 1000nH], preferably 200ηΗ (Naheng). It may also include two parallel inductors, one of which is L1 above and the other inductor L2 is grounded, and the range of L2 is [47ηΗ, 270ηΗ], preferably 68ηΗ. The signal switching unit controls the reception of the communication main antenna according to the current transmission and reception condition of the mobile network signal in the following manner: when the mobile network signal needs to be transmitted or received, the signal switching unit controls the communication main antenna to receive the mobile network signal. ; The signal switching unit controls the communication main antenna to receive the frequency modulation signal when the signal switching unit is in a non-receiving or non-transmitting mobile network signal state and needs to receive a frequency modulation signal.

The above FM receiving system enables the mobile terminal to include only one antenna. Under the premise of ensuring the basic service of the mobile terminal and the FM function, the external radio frequency function of the FM radio is realized by multiplexing the main antenna of the mobile terminal into an FM receiving antenna. The above FM receiving system can be placed in other devices having the same requirements in addition to being placed in the mobile terminal. The mobile network signal and the FM signal of the mobile terminal implementing the basic service function are all received by the main antenna of the mobile terminal, and the FM signal enters the FM chip through the matching circuit, and the mobile network signal of the mobile terminal passes through the corresponding filter, and is solved by the mobile terminal. The device receives, and the demodulation device of the mobile terminal includes a radio frequency transceiver chip and a baseband chip. The following describes the antenna multiplexing technology by using the GSM terminal and the CDMA/WCDMA terminal as examples. Other time-division terminals, such as TD-SCDMA terminals, can refer to the GSM standard terminal embodiment, and other non-time-division systems. The terminal can refer to an embodiment of a CDMA/WCDMA standard terminal. Since CDMA and WCDMA are consistent in the implementation of antenna multiplexing techniques, no distinction is made. The GSM system and the CDMA/WCDMA multimode handset method are no different from the single mode mobile terminal, and therefore will not be described separately. The multi-antenna terminal in Long Term Evolution (LTE) can also implement multiplexing of antennas by referring to the following embodiments. Any one antenna can be used as a communication main antenna, or an antenna multiplexing device can be connected to multiple antennas.

Embodiment 2 This embodiment uses a GSM mobile terminal as an example to illustrate how to multiplex a main antenna of a mobile terminal into an FM receiving antenna. As shown in FIG. 3, the FM receiving system has a GSM antenna as a communication main antenna, a signal switching unit as an antenna switch, a matching circuit as an FM matching circuit, and an FM receiving chip as an FM chip. In this system, the receiving antenna of the independent FM signal is not included, but is multiplexed between the FM receiving antenna and the GSM main antenna to ensure normal reception of the FM signal without affecting the function of the GSM main antenna. the goal of. The matching unit is an FM matching circuit as shown in FIG. 4, one end of which is connected to the FM chip, and the other end is connected to the output end of the antenna switch. For the entire mobile terminal, it can also be called a receiving loop of the GSM900 signal. In an example, the FM matching circuit and the receiving end of the GSM 900 can multiplex one output terminal of the antenna switch, and in other embodiments, can also be connected to other ports of the antenna switch, for example, the antenna switch can also be multiplexed with the receiving end of the GSM1800. All the way to output. Considering that during the normal GSM voice call, there is no FM playback. Therefore, during the standby process, it is detected whether the GSM signal is normally transmitted or received. If it is normally transmitted or received, follow the flow shown in Figure 6. The adjustment of the antenna switch, specifically: when the antenna switch is in the state of non-receiving or non-transmitting GSM signal when idle, and needs to receive the FM signal, the antenna switch turns on the path from the GSM antenna to the FM matching circuit, That is, the control communication main antenna receives the FM signal, and then the FM signal is processed by the FM chip to output an audio signal, thereby realizing FM broadcast playback. Thereby, time division multiplexing of the main antenna and the FM antenna is achieved. Figure 4 depicts the FM matching circuit of Figure 3. Among them, the receiving end of GSM900 is connected with the receiving end of the FM antenna, but the GSM band filter can filter out the signal of the FM band. The FM matching circuit is usually implemented with a large inductor (L1 in Figure 4). It has a good filtering effect on signals above 800MHz. It can filter out signals in the GSM band and enhance the receiving performance of the FM. Therefore, in this system, There is no crosstalk between the signals, and they are effectively isolated to ensure that the final performance is good. The inductance in Figure 4 is a better value. In the figure, the range of L1 is [1 ΟΟηΗ, ΙΟΟΟηΗ], and the range of L2 is [47ηΗ, 270ηΗ]. L2 in the figure is used to improve the reception performance of low frequency FM signals (such as [87 Hz, 99 Hz]). In other embodiments, the FM matching circuit may include only L1 and not L2.

Embodiment 3 This embodiment describes another manner of multiplexing an FM antenna and a main antenna, as shown in FIG. Considering that the antenna switch may have a port remaining in some cases, the FM signal can occupy the port of an antenna switch, and the terminal of the FM external release thus implemented is similar to that shown in FIG. This embodiment still introduces the scheme of the GSM mobile terminal of the current GSM900/1800 as an example. In this embodiment, the antenna switch can be 5 channels, so that the GSM reception and The launch will use 4 way. The remaining one can be used for receiving FM signals, as shown in Figure 5. The main antenna of the GSM communication system thus constructed can achieve the effect of receiving the FM signal, thereby realizing FM external release.

Embodiment 4 FIG. 6 illustrates the driving of a specific multiplexing circuit shared by an FM antenna and a GSM main antenna in a GSM mobile terminal. The specific process is as follows: Step 601, enter the FM function; When the user starts the FM function, perform the following process. Step 602: Determine whether the mobile terminal is in or about to be in communication with the GSM base station. If yes, go to step 603. If not, go to step 604. If you want to be in the immediate (in a short time interval), you will be working with the base station. Communication. At this point, the user can be prompted appropriately to increase the user experience. Step 603: Perform normal communication with the base station and GSM service processing, or switch the antenna switch to the GSM receiving path, and return to step 602. For the determination of step 602, when it is determined that the mobile terminal is communicating with the base station, Then, the process of communicating with the base station is continued, and it is determined that the mobile terminal controls the communication main antenna to receive the mobile network signal if it is to communicate with the base station. In step 604, it is determined whether there is FM data. If yes, step 605 is performed. If not, the process returns to step 602. In other embodiments, the determination of step 604 is not performed, and step 605 is directly performed. Step 605, the antenna switch is switched to have On the FM receiving link, the FM band is received. When the user exits the FM function, the above process automatically ends. The principle and process of other mobile phones are the same, so there is no need to describe them. The above communication state with the base station includes a call state, or a periodic transmission signal state, or a periodic reception signal state. That is, the signal switching unit controls the communication main antenna to receive a mobile network signal when it is required to transmit or receive a mobile network signal. The signal switching unit performs the above-described flow, and when the terminal is in the standby state and does not receive the mobile network signal and the FM signal, the signal switching unit preferably controls the communication main antenna to be in a state of not receiving for the purpose of power saving. However, the signal switching unit can also control the state in which the communication main antenna is in receiving the FM signal even if the path is turned on.

Embodiment 5 This embodiment describes a system for implementing FM external release using a CDMA or WCDMA main antenna, as shown in FIG. 7, wherein a CDMA or WCDMA antenna is a communication main antenna, a signal switching unit is a duplexer, and a matching circuit is an FM matching circuit. The FM receiving chip is an FM chip. Since the transmission and reception of the CDMA/WCDMA main antenna is completely duplex, the transmission of the signal can be simultaneously performed, and the transmission and reception are performed at the same time. Therefore, the FM matching circuit can be directly connected to the receiving link output end of the CDMA/WCDMA duplexer to receive the FM signal, and the FM matching circuit described in Embodiment 2 can be used while receiving the FM signal. , to ensure the receiving performance of the CDMA / WCDMA main antenna. In this embodiment, there is no need to modify the radio frequency driving, that is, the signal switching unit does not need to control the reception of the communication main antenna according to the current transmission and reception of the mobile network signal, but automatically realizes the signal switching, because the radio frequency receiving link is at any time. All are open. For the FM band, the FM signal is naturally also available, and the FM signal can be directly received at the output of the receiving link of the CDMA/WCDMA duplexer.

One of ordinary skill in the art will appreciate that all or a portion of the above steps may be performed by a program to instruct the associated hardware, such as a read only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the foregoing embodiment may be implemented in the form of hardware, or may be implemented in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software. It is a matter of course that the invention may be embodied in various other forms and modifications without departing from the spirit and scope of the invention.

Industrial Applicability The method, device and system of the embodiments of the present invention can multiplex the mobile service main antenna and the FM antenna, and can listen to the FM without inserting the earphone, and also avoid the dual antenna design, some antennas are not available. The problem of a drop in antenna performance due to a sufficiently good environment reduces the space left by the mobile terminal for the design of the main antenna and the FM antenna. Additionally, the methods, apparatus, and systems of the present invention do not result in degradation of antenna performance.

Claims

Claim

An apparatus for implementing an FM antenna, the apparatus comprising: a communication main antenna, an antenna multiplexing device connected to the communication main antenna, and an FM receiving chip connected to the antenna multiplexing device, wherein: the communication main antenna is set to: Receiving a mobile network signal or a frequency modulation signal; the antenna multiplexing device is configured to: control the communication main antenna to switch to receive a mobile network signal or a frequency modulation signal, and filter the received frequency modulation signal when the communication main antenna receives the frequency modulation signal The FM receiving chip is configured to: receive the filtered FM signal output by the antenna multiplexing device, and send the FM signal to the audio output unit for playing.

2. The apparatus according to claim 1, wherein: the antenna multiplexing device comprises a signal switching unit and a matching circuit, wherein: the signal switching unit is configured to: be connected to the communication main antenna, and output a mobile network signal or a frequency modulation signal. ;

The matching circuit is connected to the signal switching unit, and the matching circuit is configured to: filter the FM signal output by the signal switching unit, and output the filtered FM signal to the FM receiving chip.

3. The device according to claim 2, wherein: the signal switching unit is an antenna switch, and the signal switching unit is configured to output a mobile network signal or a frequency modulation signal according to the following manner: controlling the current transmission and reception according to the mobile network signal The reception of the communication main antenna, and the output of the mobile network signal or the FM signal.

4. The apparatus according to claim 3, wherein: the terminal of the signal switching unit outputting the mobile network signal comprises an output terminal of the first signal and an output terminal of the second signal; an input of the matching circuit and the first The signal multiplexes one output terminal or multiplexes one output terminal with the second signal.

5. Apparatus according to claim 3 wherein: the input of said matching circuit independently occupies an output terminal of said antenna switch.

6. The apparatus of claim 2, wherein: the signal switching unit is a duplexer.

7. Apparatus according to claim 6 wherein:

An input of the matching circuit multiplexes an output terminal of the duplexer with the mobile network signal.

8. The apparatus according to any one of claims 2, wherein: said matching circuit comprises an inductance L1, one end of said L1 is connected to an output of said signal switching unit, and the other end is connected to an input of said frequency modulation chip The value of L1 is [100nH, 1000nH].

9. The apparatus of claim 8, wherein: said L1 has a value of 200 nH.

10. The apparatus according to any one of claims 2-7, wherein: the matching circuit comprises: a first inductor L1 and a second inductor L2, one end of the L1 being connected to an output of the signal switching unit, The other end is connected to the input of the FM chip, one end of the L2 is connected to one end of the L1 connected to the FM chip, and the other end is grounded; the value range of the L1 is [ΙΟΟηΗ, ΙΟΟΟηΗ], the L2 The value range is [47ηΗ, 270ηΗ].

11. The apparatus according to claim 10, wherein: the value of the L1 is 200 Η, and the value of the L2 is 68 Η.

12. Apparatus according to any of claims 1-7, wherein: said audio output unit is a speaker.

13. The apparatus according to any one of claims 3-5, wherein: the signal switching unit is configured to control reception of the communication main antenna according to a current transmission and reception condition of a mobile network signal in the following manner: when transmission or Receiving a mobile network signal, the signal switching unit controls the communication main antenna to receive a mobile network signal; when the signal switching unit is in a non-receiving or non-transmitting mobile network signal state, and needs to receive a frequency modulated signal, the signal switching The unit controls the communication main antenna to receive the FM signal.

A mobile terminal, the terminal comprising: the FM antenna implementation device according to claims 1-9.

15. A method for implementing an FM antenna, the method comprising: after the frequency modulation function is turned on, if it is determined that the mobile terminal is communicating with the base station, continuing the process of communicating with the base station, if it is determined that the mobile terminal is to communicate with the base station, controlling the communication main antenna Receiving a mobile network signal, if it is determined that the mobile terminal is neither in a state of communicating with the base station nor in a state to be in communication with the base station, controlling the communication main antenna to receive the FM signal.

16. The method of claim 15, the method further comprising: controlling the communication main antenna to be in a state of not receiving a signal after exiting the frequency modulation function.