CN102647200A - A radio frequency front-end receiving device, transmitting device and terminal - Google Patents

Abstract

The invention relates to a radio frequency front-end receiving device, emitting device and terminal. The radio frequency front-end receiving device is characterized in that a broadband front-end filter and a parallel circuit are sequentially arranged between an antenna and a radio frequency chip, and the parallel circuit is connected with the broadband front-end filter in series; in the parallel circuit, a narrow-band front-end filter is connected with a conducting wire in parallel; and one end of the parallel circuit close to the broadband front-end filter is provided with a switch control circuit which is used for controlling a signal to pass through the narrow-band front-end filter or the conducting wire. The design difficulty and the cost can be reduced, and the radio frequency front-end receiving device solves the problems in the prior art that the design index requirement of the narrow-band front-end filter is higher; and a low-noise amplification device needs to be added, and the cost and the area of the radio frequency chip are increased and the like.

Description

A radio frequency front-end receiving device, transmitting device and terminal

technical field

The invention relates to a radio frequency front-end receiving device, a transmitting device and a terminal in the wireless field.

Background technique

A schematic diagram of the frame structure of a common terminal chip in the prior art is shown in Figure 1, including a front-end filter, a power amplifier (PA), a radio frequency chip and a baseband chip, wherein the radio frequency chip in the receiving part is composed of the low noise amplifier ( LNA), demodulator, amplifier (AMP), the RF chip of the transmitting part is composed of the amplifier, modulator, and filter in the lower part of Figure 1; the baseband chip includes an analog-to-digital converter (ADC) and a digital-to-analog converter ( DAC) and digital baseband section. In general, if the adjacent frequency band of the narrowband frequency band is the frequency band of the same mode, such as frequency division duplex mode (FDD) and time division duplex mode (TDD), the terminal RF front-end part can only use a front-end of a wider bandwidth system filter.

However, as shown in Figure 2, when the terminal moves from an area with a wider system bandwidth to an area with a narrower system bandwidth in the same frequency band of another operator or region (such as moving from a 20M system bandwidth to an area with a 10MHz system bandwidth), And the adjacent frequency bands have different modes. Considering the interference of the FDD system to the TDD system, a filter suitable for the narrower system bandwidth must be added in the terminal RF front-end design to filter out the influence of the FDD frequency band.

In view of the situation in Figure 2, the traditional RF front-end design method adopts a parallel structure of multiple front-end filters supporting different bandwidths. The structure before the demodulator of the receiving part is shown in Figure 3. Add a switch to point to the front-end filter of the required bandwidth, and at the same time need to add a front-end filter that supports different bandwidths. In addition, the RF chip also needs to add a corresponding low-noise amplifier (LNA). The structure after the transmitting part of the power amplifier is shown in Figure 4. The added switch points to the front-end filter of the required bandwidth, and several front-end filters supporting different bandwidths need to be added at the same time.

In the traditional RF front-end design method, as shown in Figure 3 and Figure 4, since the terminal is in a narrower system bandwidth, the signal is only filtered by the front-end filter that supports the narrower bandwidth, so the design index of the narrower bandwidth front-end filter The requirements are relatively high (the near-end and far-end suppression requirements are relatively strict), and the front-end filter design requirements are difficult; and the receiving part needs to add an additional low-noise amplifier (LNA), which increases the cost and area of the RF chip.

Contents of the invention

The purpose of the present invention is to provide a radio frequency front-end receiving device, a transmitting device and a terminal in order to reduce design difficulty and cost.

In order to achieve the above object, according to one aspect of the present invention, a radio frequency front-end receiving device is provided, between the antenna and the radio frequency chip, a broadband front-end filter and a parallel circuit connected in series with the broadband front-end filter are arranged in sequence; In the parallel circuit, the narrow-band front-end filter is connected in parallel with the wire, and a switch control circuit for controlling signals passing through the narrow-band front-end filter or the wire is provided adjacent to one end of the wide-band front-end filter in the parallel circuit.

Preferably, the switch control circuit may include a single-pole multi-throw switch for controlling signals passing through the narrow-band front-end filter or the wire.

Preferably, the wideband front-end filter is a wideband frequency band filter in time division duplex mode TDD or a broadband frequency band front end filter in frequency division duplex mode FDD, and the narrowband front end filter can be a narrowband frequency band in time division duplex mode TDD filter or narrowband front-end filter for frequency division duplex mode FDD.

Preferably, another switch control circuit that cooperates with the switch control circuit adjacent to the broadband front-end filter to control signals passing through the narrow-band front-end filter or wires may be provided at one end of the parallel circuit adjacent to the radio frequency chip.

Preferably, the switch control circuit adjacent to the radio frequency chip and the switch control circuit adjacent to the broadband front-end filter are parity circuits.

In order to achieve the above object, according to another aspect of the present invention, a radio frequency front-end transmitting device is provided, between the power amplifier and the antenna, a broadband front-end filter and a parallel circuit connected in series with the broadband front-end filter are sequentially provided; In the parallel circuit, the narrow-band front-end filter is connected in parallel with the wire, and a switch control circuit for controlling signals passing through the narrow-band front-end filter or the wire is provided adjacent to one end of the wide-band front-end filter in the parallel circuit.

Preferably, the switch control circuit may include a single-pole multi-throw switch for controlling signals passing through the narrow-band front-end filter or the wire.

Preferably, the wideband front-end filter is a wideband frequency band filter in time division duplex mode TDD or a broadband frequency band front end filter in frequency division duplex mode FDD, and the narrowband front end filter can be a narrowband frequency band in time division duplex mode TDD filter or narrowband front-end filter for frequency division duplex mode FDD.

Preferably, another switch control circuit that cooperates with the switch control circuit adjacent to the broadband front-end filter to control signals passing through the narrow-band front-end filter or wires may be further provided at one end of the parallel circuit adjacent to the antenna.

Preferably, the switch control circuit adjacent to the radio frequency chip and the switch control circuit adjacent to the broadband front-end filter are parity circuits.

In order to achieve the above object, according to another aspect of the present invention, a terminal is provided, including any one of the above radio frequency front-end receiving devices, radio frequency front-end transmitting devices, or a combination of both.

The present invention proposes a radio frequency front-end receiving device, a radio frequency front-end transmitting device and a terminal. By setting a serial broadband front-end filter and a parallel circuit, when in a broadband system, the control signal of the switch control circuit does not pass through the narrow-band front-end filter, the signal Only pass through the wideband front-end filter; when in a narrowband system and the adjacent frequencies are in different modes, the control signal of the switch control circuit passes through one of the narrowband front-end filters in the parallel circuit, and the signals pass through the wideband front-end filter and the narrowband front-end filter respectively .

In the present invention, since the wideband front-end filter has sufficiently suppressed far-end spurs, the far-end suppression capability requirements of the narrowband front-end filter in the receiving and transmitting devices can be reduced, thereby reducing the radio frequency design of the narrowband front-end filter Index; In addition, since the radio frequency chip is connected in series in the receiving and transmitting device of the present invention, the number of LNAs in the radio frequency chip is reduced compared with the parallel structure of the prior art, thus reducing the cost and area of the radio frequency chip.

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

Description of drawings

FIG. 1 is a schematic diagram of a frame structure of a terminal chip in the prior art;

FIG. 2 is a schematic diagram of a terminal moving to a narrowband area and adjacent frequencies in different modes;

FIG. 3 is a structural schematic diagram of a plurality of receiving radio frequency front ends supporting different bandwidths in the prior art;

Fig. 4 is a structural schematic diagram of multiple radio frequency front-ends supporting different bandwidths in the prior art

FIG. 5 is a structural schematic diagram of Embodiment 1 of a radio frequency front-end receiving device of the present invention;

6 is a schematic structural diagram of Embodiment 2 of the radio frequency front-end receiving device of the present invention;

7 is a schematic structural diagram of Embodiment 3 of the radio frequency front-end receiving device of the present invention;

FIG. 8 is a structural schematic diagram of Embodiment 1 of the radio frequency front-end transmitting device of the present invention;

9 is a schematic structural diagram of Embodiment 2 of the radio frequency front-end transmitting device of the present invention;

FIG. 10 is a schematic structural diagram of Embodiment 3 of the radio frequency front-end transmitting device of the present invention.

Detailed ways

FIG. 5 is a structural schematic diagram of Embodiment 1 of a radio frequency front-end receiving device of the present invention. As shown in Figure 5, the RF front-end receiving device of this embodiment includes:

Broadband front-end filter, as shown in Figure 5, one end of the broadband front-end filter is connected to the antenna, and the other end is connected in series with the parallel circuit;

In the parallel circuit, N narrowband front-end filters (N ≥ 1) are connected in parallel, and each narrowband front-end filter is connected in parallel with a wire for transmitting signals, and a switch control circuit is provided at one end of the parallel circuit adjacent to the broadband front-end filter. A switch control circuit is used to control the signal passing through the wire or one of the narrowband front-end filters.

The following introduces the working process of the radio frequency front-end receiving device of the present invention: when in a wide bandwidth TDD system (such as 20MHz), the switch control circuit control signal points to point A shown in Figure 5, that is, the signal received by the antenna passes through the broadband front-end After the filter is filtered, it is directly connected to the radio frequency chip of the receiver; when it is in a system with a narrow bandwidth (for example, 10MHz) and the adjacent frequency is still a TDD system, the control signal of the switch control circuit points to point A shown in Figure 5, and the radio frequency The design of the front-end receiving part can share the broadband front-end filter; when it is in a system with a narrow bandwidth (for example, 10MHz) and the adjacent frequency is an FDD system, the control signal of the switch control circuit points to B to K shown in Figure 5. One point, the wideband front-end filter is connected in series with a narrowband front-end filter that supports a narrower bandwidth, that is, the signal received by the antenna is first filtered by the wideband front-end filter, and then further filtered by the required narrowband front-end filter, and finally the The twice-filtered signal is connected to the RF chip.

Those skilled in the art should understand that the present invention is not only applicable to the TDD system, as shown in Figure 2, moving from the wider area of the TD-LTE system bandwidth to the narrower area of the system bandwidth of the same frequency band in other operators or regions (such as TD-LTE LTE customers roam to other countries or operators, and the TD-LTE allocation spectrum bandwidth of the roaming place is narrow), and the adjacent band is FDD; and it is suitable for moving from an area with a wide FDD bandwidth to the same frequency band of other operators or regions Areas with narrow system bandwidth (such as CDMA customers roaming to other countries or operators, and the roaming CDMA allocated spectrum bandwidth is narrow), and the adjacent band is TDD, as long as it is from a broadband system of one mode to a narrowband system, And when the adjacent frequency is another mode system, in order to avoid interference, the present invention can be applied.

Beneficial effects of the present invention: since the wideband front-end filter has sufficiently suppressed the far-end spurs, the requirement for the far-end suppression ability of the narrowband front-end filter can be reduced, thereby reducing the radio frequency design index of the narrowband front-end filter; in addition Compared with the parallel structure of the prior art, the number of LNAs in the radio frequency chip is reduced (the more system bandwidth is supported, the greater the number of corresponding LNA devices is reduced), thus reducing the cost and area of the radio frequency chip.

Those skilled in the art should understand that the narrowband front-end filter can be configured according to the required support bandwidth, for example, the TD-LTE system can be configured as 15/10/5/1.4MHz, the WCDMA system can be configured as 5MHz, and the FDD-LTE system can be configured as The configuration is 15/10/5/1.4MHz, and the number of corresponding narrowband front-end filter branches of the parallel circuit can also be increased according to the amount of supported bandwidth.

FIG. 6 is a schematic structural diagram of Embodiment 2 of the radio frequency front-end receiving device of the present invention. FIG. 7 is a schematic structural diagram of Embodiment 3 of the radio frequency front-end receiving device of the present invention. Fig. 6 shows the case where only one narrow-band front-end filter is connected in parallel in the parallel circuit, and Fig. 7 shows the case where the wire is connected in parallel with N narrow-band front-end filters. As shown in Figure 6, the switch control circuit is a single-pole double-throw switch, and the switch control circuit in Figure 7 is a single-pole multi-throw switch, and the number of control branches of the single-pole multi-throw switch is equal to the number of all narrowband front-end filters Add 1 to the number (wire branch).

As shown in Fig. 6 and Fig. 7, another switch control circuit may be provided adjacent to the end of the radio frequency chip in the parallel circuit, and may be the same circuit as the switch control circuit adjacent to the broadband front-end filter. Those skilled in the art should understand that the parity circuit referred to herein refers to the RF front-end and RF chip switches pointing to the same front-end filter according to the system operating bandwidth, as shown in Figure 6 and Figure 7, the switch control circuit adjacent to the broadband front-end filter Wherever the switch is turned on, the group of switches far away from the switch control circuit of the broadband front-end filter is also turned on, and the two are in the same position to ensure that the same front-end filter is connected.

Fig. 8 is a structural schematic diagram of Embodiment 1 of the radio frequency front-end transmitting device of the present invention. As shown in Fig. 8, the radio frequency front-end transmitting device of this embodiment includes: a broadband front-end filter, as shown in Fig. 8, one end of the broadband front-end filter is connected to the power amplifier, The other end is connected in series with the parallel circuit; in the parallel circuit, N narrow-band front-end filters (N≥1) are connected in parallel, and each narrow-band front-end filter is connected in parallel with the wire used to transmit the signal, and the parallel circuit is adjacent to the wide-band front-end filter One end is provided with a switch control circuit, and the switch control circuit is used to control the signal to pass through the wire or one of the narrow-band front-end filters.

The following introduces the working process of the RF front-end transmitting device of the present invention: when in a TDD system with a wider bandwidth (such as 20MHz), the switch control circuit control signal points to point A shown in Figure 8, that is, the signal through the power amplifier is filtered by the broadband front-end Filtered by the filter and directly connected to the antenna for transmission; when in a system with a narrow bandwidth (for example, 10MHz) and the adjacent frequency is still a TDD system, the switch control circuit control signal points to point A shown in Figure 8, and the RF front-end transmitting part The design can share the wideband front-end filter; when it is in a narrow bandwidth system (such as 10MHz) and the adjacent frequency is an FDD system, the switch control circuit control signal points to one of B to K shown in Figure 8, and the wideband The front-end filter is connected in series with a narrow-band front-end filter that supports a narrower bandwidth, that is, the signal that passes through the power amplifier is first filtered by the wide-band front-end filter, and then further filtered by the required narrow-band front-end filter, and finally filtered twice The signal is sent to the antenna for transmission.

FIG. 9 is a schematic structural diagram of Embodiment 2 of the radio frequency front-end transmitting device of the present invention. FIG. 10 is a schematic structural diagram of Embodiment 3 of the radio frequency front-end transmitting device of the present invention. Fig. 9 shows the case where only one narrowband front-end filter is connected in parallel in the parallel circuit, and Fig. 10 shows the case where the wire is connected in parallel with N narrowband front-end filters. As shown in Figure 9, the switch control circuit is a single-pole double-throw switch, and the switch control circuit in Figure 10 is a single-pole multi-throw switch, and the number of control branches of the single-pole multi-throw switch is equal to the number of all narrowband front-end filters Add 1 to the number (wire branch). As shown in FIG. 9 and FIG. 10 , another switch control circuit may be provided adjacent to the end of the radio frequency chip in the parallel circuit, and may be in the same position as the switch control circuit adjacent to the broadband front-end filter.

Those skilled in the art should understand that the radio frequency front-end receiving or transmitting device of the present invention, its core device is a broadband filter and a parallel circuit connected in series, the difference is that the receiving device is located between the antenna and the radio frequency chip, and the transmitting device is located between the power amplifier and the antenna Between, Fig. 5-Fig. 7 also applies to the transmitting device for the scope of application and the configuration of the narrowband front-end filter.

The present invention also claims to protect a terminal including any radio frequency front-end receiving device in Fig. 5-Fig. 7 above, or a terminal including any radio-frequency front-end transmitting device in Fig. 8-Fig. The internal structure of the terminal in the prior art is adopted, and Figs. 5-10 have clearly shown the structures of the receiving and transmitting devices, therefore, the terminal of the present invention will not be redrawn.

The terminal protected by the present invention can be applied to scenarios supporting multiple TD-LTE bandwidths; in order for a TD-LTE terminal to work normally in an environment where the system bandwidth is narrow and adjacent to the FDD spectrum, only a switch control circuit and a switch control circuit need to be added to the terminal according to the present invention. The filter is connected in series, and the series structure of the filter reduces the design complexity and reduces the cost of the radio frequency chip. Of course, it is also applicable to the scenario of supporting multiple CDMA bandwidths, and it can realize that CDMA terminals can work normally in an environment where the system bandwidth is narrow and adjacent to the TDD spectrum.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be The scheme shall be modified or equivalently replaced without departing from the spirit and scope of the technical scheme of the present invention.

Claims (13)

1. a radio-frequency front-end receiving system is characterized in that, between the radio frequency chip, is provided with the wideband frontend filter at antenna successively, and the parallel circuits of connecting with said wideband frontend filter;

In the said parallel circuits, the arrowband front end filter is parallelly connected with lead, and contiguous said wideband frontend filter one end is provided with and is used for the ON-OFF control circuit of control signal through said arrowband front end filter or said lead in the said parallel circuits.

2. radio-frequency front-end receiving system according to claim 1 is characterized in that, said ON-OFF control circuit comprises the single pole multiple throw that is used for control signal process said arrowband front end filter or said lead.

3. radio-frequency front-end receiving system according to claim 1; It is characterized in that; The broadband frequency range front end filter of broadband frequency band filter that said wideband frontend filter is TDD mode TDD or mode of frequency division duplexing FDD, said arrowband front end filter are the arrowband frequency range front end filter of arrowband frequency band filter or the mode of frequency division duplexing FDD of TDD mode TDD.

4. according to each described radio-frequency front-end receiving system of claim 1-3; It is characterized in that contiguous said radio frequency chip one end also is provided with the ON-OFF control circuit of contiguous said wideband frontend filter and cooperates control signal another ON-OFF control circuit through said arrowband front end filter or lead in the said parallel circuits.

5. radio-frequency front-end receiving system according to claim 4 is characterized in that, the ON-OFF control circuit of contiguous said radio frequency chip is the coordination circuit with the ON-OFF control circuit of contiguous said wideband frontend filter.

6. a radio-frequency front-end emitter is characterized in that, between the antenna, is provided with the wideband frontend filter at power amplifier successively, and the parallel circuits of connecting with said wideband frontend filter;

In the said parallel circuits, the arrowband front end filter is parallelly connected with lead, and contiguous said wideband frontend filter one end is provided with and is used for the ON-OFF control circuit of control signal through said arrowband front end filter or said lead in the said parallel circuits.

7. radio-frequency front-end emitter according to claim 6 is characterized in that, said ON-OFF control circuit comprises the single pole multiple throw that is used for control signal process said arrowband front end filter or said lead.

8. radio-frequency front-end emitter according to claim 6; It is characterized in that; The broadband frequency range front end filter of broadband frequency band filter that said wideband frontend filter is TDD mode TDD or mode of frequency division duplexing FDD, said arrowband front end filter are the arrowband frequency range front end filter of arrowband frequency band filter or the mode of frequency division duplexing FDD of TDD mode TDD.

9. according to each described radio-frequency front-end emitter of claim 6-8; It is characterized in that contiguous said antenna one end also is provided with the ON-OFF control circuit of contiguous said wideband frontend filter and cooperates control signal another ON-OFF control circuit through said arrowband front end filter or lead in the said parallel circuits.

10. radio-frequency front-end emitter according to claim 9 is characterized in that, the ON-OFF control circuit of contiguous said radio frequency chip is the coordination circuit with the ON-OFF control circuit of contiguous said wideband frontend filter.

11. a terminal is characterized in that, comprises any described radio-frequency front-end receiving system of aforesaid right requirement 1-5.

12. a terminal is characterized in that, comprises each described radio-frequency front-end emitter of aforesaid right requirement 6-10.

13. terminal; It is characterized in that; Comprise any described radio-frequency front-end receiving system of aforesaid right requirement 1-5; And each described radio-frequency front-end emitter of claim 6-10, said radio-frequency front-end receiving system is connected with baseband chip with the middle radio frequency chip through series connection of said radio-frequency front-end emitter.

Images