Disclosure of Invention
Therefore, it is necessary to provide a TDD and FDD compatible LTE rf transceiver circuit with a simple structure, aiming at the problem that the structure of the general TDD and FDD compatible LTE rf transceiver circuit is complex.
An LTE radio frequency transceiver circuit compatible with TDD and FDD comprises an antenna, a selection component set, a duplex component, a filter component, an isolation component, a first radio frequency switch, a second radio frequency switch, a radio frequency receiving circuit and a radio frequency transmitting circuit;
the selection component set comprises a first selection component, a second selection component, a third selection component, a fourth selection component, a fifth selection component, a sixth selection component and a seventh selection component, and each selection component in the selection component set is provided with a first interface, a second interface and a third interface;
the antenna is connected with a first interface of the first selection component, a second interface of the first selection component is connected with the duplex component, a third interface of the first selection component is connected with the filter component, the filter component is connected with a first port of the first radio frequency switch, the duplex component is connected with a second interface of the second selection component, the first interface of the second selection component is connected with a first interface of the third selection component, a third interface of the second selection component is connected with a second port of the first radio frequency switch, a second interface of the third selection component is connected with a second interface of the fourth selection component, a third interface of the third selection component is connected with a first port of the second radio frequency switch, a second port of the second radio frequency switch is connected with a third interface of the fourth selection component, the first interface of the fourth selection component is connected with the radio frequency receiving circuit, and a third interface of the fifth selection component is connected with a third port of the first radio frequency switch, the second interface of the fifth selection component is connected with the duplex component, the first interface of the fifth selection component is connected with the first interface of the sixth selection component, the second interface of the sixth selection component is connected with the isolation component, the third interface of the sixth selection component is connected with the third interface of the seventh selection component, the second interface of the seventh selection component is connected with the isolation component, and the first interface of the seventh selection component is connected with the radio frequency transmission circuit;
when the FDD mode is in, the first interfaces of the selection components in the selection component set are respectively communicated with the corresponding second interfaces.
The LTE radio frequency transceiver circuit compatible with TDD and FDD comprises an antenna, a selection component set, a duplex component, a filter component, an isolation component, a radio frequency receiving circuit and a radio frequency transmitting circuit, wherein the selection component set comprises a plurality of selection components, and when the selection components are in a TDD mode, a first interface of each selection component is respectively communicated with a corresponding third interface; when the wireless transceiver is in the FDD mode, the first interfaces of the selection components in the selection component set are respectively communicated with the corresponding second interfaces, and LTE radio frequency transceiving compatible with TDD and FDD can be realized without a complex circuit structure. In addition, each interface of the selection component can be accessed/replaced by a duplex component, a filter component, an isolation component, a radio frequency receiving circuit and a radio frequency transmitting circuit of different types according to requirements, and the LTE wireless receiving and transmitting requirements of multiple frequency band applications in compatible TDD and FDD modes are met.
Detailed Description
As shown in fig. 1, an LTE radio frequency transceiver circuit compatible with TDD and FDD includes an antenna 100, a selection component set, a duplexing component 300, a filtering component 400, an isolation component 500, a first radio frequency switch 600, a second radio frequency switch 700, a radio frequency receiving circuit 800, and a radio frequency transmitting circuit 900;
the selection component set comprises a first selection component 210, a second selection component 220, a third selection component 230, a fourth selection component 240, a fifth selection component 250, a sixth selection component 260 and a seventh selection component 270, and each selection component in the selection component set is provided with a first interface, a second interface and a third interface respectively;
the antenna 100 is connected to the first interface of the first selection component 210, the second interface of the first selection component 210 is connected to the duplex component 300, the third interface of the first selection component 210 is connected to the filter component 400, the filter component 400 is connected to the first port of the first rf switch 600, the duplex component 300 is connected to the second interface of the second selection component 220, the first interface of the second selection component 220 is connected to the first interface of the third selection component 230, the third interface of the second selection component 220 is connected to the second port of the first rf switch 600, the second interface of the third selection component 230 is connected to the second interface of the fourth selection component 240, the third interface of the third selection component 230 is connected to the first port of the second rf switch 700, the second port of the second rf switch 700 is connected to the third interface of the fourth selection component 240, the first interface of the fourth selection component 240 is connected to the rf receiving circuit 800, a third interface of the fifth selecting component 250 is connected to the third port of the first rf switch 600, a second interface of the fifth selecting component 250 is connected to the duplex component 300, a first interface of the fifth selecting component 250 is connected to a first interface of the sixth selecting component 260, a second interface of the sixth selecting component 260 is connected to the isolating component 500, a third interface of the sixth selecting component 260 is connected to a third interface of the seventh selecting component 270, a second interface of the seventh selecting component 270 is connected to the isolating component 500, and a first interface of the seventh selecting component 270 is connected to the rf transmitting circuit 900;
when the FDD mode is in, the first interfaces of the selection components in the selection component set are respectively communicated with the corresponding second interfaces.
The antenna 100 is used for transmitting and receiving external electromagnetic wave signals. The duplexer 300 may be a duplexer, which is a different frequency duplex radio station and is a main accessory of a relay station, and functions to isolate transmitted and received signals and ensure that both receiving and transmitting can work normally at the same time. The filtering component 400 may be embodied as a filter for filtering out noise in the link. The isolation component 500 may be an isolator that is used to isolate the signal a second time to direct the signal in a desired direction (the direction of the arrow in the isolator in fig. 1). The radio frequency switch belongs to the signal switch for cable TV network or communication field, and is used for controlling the passing of cable transmission radio frequency signal, and is formed from shell, two crystal diodes and input, output and control end connected with auxiliary circuit, one crystal diode is series-connected with AC signal channel, and another diode is connected with signal channel and AC signal ground. The rf receiving circuit 800 is configured to receive an uplink signal, and specifically, the rf receiving circuit 800 may include a low noise amplifier, a first filter, a first mixer, and an analog-to-digital converter, which are connected in sequence. The radio frequency transmitting circuit 900 is configured to transmit a downlink signal, and specifically, the radio frequency transmitting circuit 900 may include a power amplifier, a second filter, a second mixer, and a digital-to-analog converter, which are connected in sequence.
The selection component set is a general name of a plurality of selection components, each selection component comprises a first interface, a second interface and a third interface, and the selection components can select the first interface to be conducted with the second interface or select the first interface to be conducted with the third interface according to needs, so that control and switching are achieved. In addition, in the LTE radio frequency transceiver circuit compatible with TDD and FDD of the present invention, the connection points between the antenna 100, the duplex component 300, the filter component 400, the isolation component 500, the first radio frequency switch 600, the second radio frequency switch 700, the radio frequency receiver circuit 800, and the radio frequency transmitter circuit 900 are all provided with selection components, and the antenna 100, the duplex component 300, the filter component 400, the isolation component 500, the first radio frequency switch 600, the second radio frequency switch 700, the radio frequency receiver circuit 800, and the radio frequency transmitter circuit 900 of different models (operating frequency bands) can be conveniently replaced according to the requirements of the current application environment.
The LTE radio frequency transceiver circuit compatible with TDD and FDD comprises an antenna 100, a selection component set, a duplex component 300, a filter component 400, an isolation component 500, a radio frequency receiving circuit 800 and a radio frequency transmitting circuit 900, wherein the selection component set comprises a plurality of selection components, and when the selection components are in a TDD mode, a first interface of each selection component is respectively communicated with a corresponding third interface; when the wireless transceiver is in the FDD mode, the first interfaces of the selection components in the selection component set are respectively communicated with the corresponding second interfaces, and LTE radio frequency transceiving compatible with TDD and FDD can be realized without a complex circuit structure. In addition, each interface of the selection component can be accessed/replaced by the duplex component 300, the filter component 400, the isolation component 500, the radio frequency receiving circuit 800 and the radio frequency transmitting circuit 900 of different models as required, so that the LTE wireless transceiving requirement of being compatible with multiple frequency band applications in TDD and FDD modes is met.
To further describe the specific structure and operation of the TDD and FDD compatible LTE radio frequency transceiver circuit of the present invention in detail, a specific example will be used in conjunction with fig. 2 and fig. 3. Fig. 2 and 3 further illustrate the interfaces for the selection module, wherein the first interface is illustrated by a, the second interface is illustrated by b, and the third interface is illustrated by c.
As shown in fig. 2, in TDD mode:
the uplink, the antenna 100 → the first selecting component 210 first interface a → the first selecting component 210 third interface c → the filtering component 400 → the first radio frequency switch 600 → the second selecting component 220 third interface c → the second selecting component 220 first interface a → the third selecting component 230 third interface c → the second radio frequency switch 700 → the fourth selecting component 240 third interface c → the fourth selecting component 240 first interface a → the radio frequency receiving module 800.
The downlink, the radio frequency transmitting module 900 → the seventh selecting component 270 first interface a → the seventh selecting component 270 third interface c → the sixth selecting component 260 first interface a → the fifth selecting component 250 third interface c → the first radio frequency switch 600 → the filter component 400 → the first selecting component 210 third interface c → the first selecting component 210 first interface a → the antenna 100.
As shown in fig. 3, in FDD mode:
the uplink, the antenna 100 → the first selection component 210 first interface a → the first selection component 210 second interface b → the duplex component 300 → the second selection component 220 second interface b → the second selection component 220 first interface a → the third selection component 230 second interface b → the fourth selection component 240 first interface a → the radio frequency receiving module 800.
The downlink, the radio frequency transmitting module 900 → the seventh selecting component 270 first interface a → the seventh selecting component 270 second interface b → the isolator 500 → the sixth selecting component 260 second interface b → the sixth selecting component 260 first interface a → the fifth selecting component 250 second interface b → the duplex component 300 → the first selecting component 210 second interface b → the first selecting component 210 first interface a → the antenna 100.
As shown in fig. 4, in one embodiment, each selection component in the selection component set further includes a first rf path capacitor pad 21 and a second rf path capacitor pad 22, which are orthogonally disposed, where the first rf path capacitor pad includes a first pad 21-1 and the second rf path capacitor pad 22 includes a third pad and a fourth pad 22-4; the first bonding pad 21-1 is used for welding an external first radio frequency channel capacitor, the fourth bonding pad 22-4 is used for welding an external second radio frequency channel capacitor, and the second bonding pad and the third bonding pad are subjected to stitch welding to form a stitch bonding pad 23; the first interface a is connected to the overlay pad 23, the second interface b is connected to the first pad 21-1, and the third interface c is connected to the fourth pad 22-4.
In this embodiment, each selecting component has the same structure, and includes, in addition to a first interface, a second interface, and a third interface, a first radio frequency path capacitor pad 21 (a dashed line frame in fig. 4) and a second radio frequency path capacitor pad 22 (a dashed line frame in fig. 4) that are orthogonally arranged, where the first radio frequency path capacitor pad includes a first pad 21-1 and a second pad, the second radio frequency path capacitor pad includes a third pad and a fourth pad 22-4, the second pad and the third pad are stitch-welded to form a stitch-pad, the first pad 21-1 may be welded with a first radio frequency path capacitor as needed, and when the first pad is welded with the first radio frequency path capacitor, the first interface is conducted with the second interface; a second radio frequency capacitor can be welded on the fourth pad 22-4 as required, and when a second radio frequency access capacitor is welded on the fourth pad, the first interface is conducted with the third interface. In the selection assembly, a first radio frequency channel capacitor pad and a second radio frequency channel capacitor pad of two packages with the same size are respectively orthogonal, and one pad of the two radio frequency channel capacitor pads is overlapped with the other pad, so that different signal flow directions are selected on a radio frequency channel.
As shown in fig. 5, in one embodiment, the TDD and FDD compatible LTE radio frequency transceiver circuit further includes a load connected to the third port of the second radio frequency switch 700.
The load and the second rf switch 700 work in coordination to effectively increase the uplink and downlink isolation in the TDD mode. Optionally, the load may be a 50 ohm load.
As shown in fig. 5, in one embodiment, the rf receiving circuit 800 includes a low noise amplifier, a first filter, a first mixer and an analog-to-digital converter, which are connected in sequence, and the low noise amplifier is connected to the first interface of the fourth selecting component 240.
The radio frequency receiving circuit 800 may adopt the radio frequency receiving circuit 800 of the zero intermediate frequency scheme, when the TDD-LTE working frequency band is 2300MHz to 2400MHz, the second mixer adopts the same local oscillation frequency as the first mixer, and the local oscillation frequency is 2350 MHz; when the FDD-LTE uplink working frequency is 1920 MHz-1980 MHz, the first frequency mixer adopts a frequency mixer with the local oscillation frequency of 1940 MHz; when the FDD-LTE downlink working frequency is 2110 MHz-2170 MHz, the second frequency mixer adopts a frequency mixer with local oscillation frequency of 2140 MHz.
As shown in fig. 5, in one embodiment, the rf transmitting circuit 900 includes a power amplifier, a second filter, a second mixer and a digital-to-analog converter, which are connected in sequence, and the power amplifier is connected to the first interface of the seventh selecting component 270.
The radio frequency transmitting circuit 900 may adopt a radio frequency transmitting circuit 900 of a zero intermediate frequency scheme, and when the TDD-LTE working frequency band is 2300MHz to 2400MHz, the second mixer adopts a mixer of which the local oscillator frequency is 2350 MHz; when the FDD-LTE uplink working frequency is 1920 MHz-1980 MHz, the second frequency mixer adopts a frequency mixer with the local oscillation frequency of 1940 MHz.
To further explain the structure and the operation of the TDD and FDD compatible LTE rf transceiver circuit of the present invention in detail, two specific examples operating in the TDD mode and the FDD mode will be used for the following description.
When the LTE radio frequency transceiver circuit compatible with TDD and FDD of the present invention operates in TDD mode, as shown in fig. 6, its operating frequency band is TDD-LTE band40 frequency band (2300 MHz-2400 MHz), and a radio frequency transceiver using zero intermediate frequency scheme is used. The downlink working process of the radio frequency transceiver is as follows: the digital-to-analog converter converts the baseband digital signal into an analog signal, the analog signal is subjected to up-mixing by a second mixer with a local oscillation signal of 2350MHz, the signal is filtered by a filter and then is connected with a power amplifier in a corresponding working frequency band, the radio frequency signal is amplified, and the amplified signal is transmitted to the filter in the corresponding working frequency band in a TDD downlink time slot through the first radio frequency switch 600 and then is transmitted through the antenna 100. The uplink working process of the radio frequency transceiver is as follows: after receiving a wireless signal through the antenna 100, the wireless signal is filtered through a filter corresponding to a working frequency band and a working bandwidth, a radio frequency signal after the first radio frequency switch 600 is switched to the second radio frequency switch 700 in a TDD uplink timeslot is transmitted to a low noise amplifier to be amplified, the amplified signal is transmitted to a filter corresponding to the working frequency band and the working bandwidth, then the amplified signal is subjected to down-mixing through a first mixer with a local oscillation signal of 2350MHz, and an analog signal subjected to down-mixing is converted into a baseband digital signal through an analog-to-digital converter (ADC). In this embodiment, in the LTE radio frequency transceiver circuit compatible with TDD and FDD of the present invention, the first interface and the third interface of the first selection component 210, the second selection component 220, the third selection component 230, the fourth selection component 240, the fifth selection component 250, the sixth selection component 260, and the seventh selection component 270 are conducted, the first pad in the selection component is welded with a radio frequency access capacitor, the stitch bonding pad technology is adopted, the duplexer is default, and the isolator is default. Second rf switch 700 to increase TDD uplink and downlink isolation, a 50 ohm load is added at second rf switch 700 in TDD mode. Meanwhile, in this embodiment, the multiplexing of multiple working bands in the TDD mode can be implemented by changing functional module devices that are packaged in the same package and have different working bands and working bandwidths at each selected component interface.
When the LTE radio frequency transceiver circuit compatible with TDD and FDD works in the FDD mode, as shown in FIG. 7, the working frequency Band is FDD-LTE Band1 frequency Band (the uplink working frequency Band is 1920 MHz-1980 MHz, and the downlink working frequency Band is 2110 MHz-2170 MHz), and the radio frequency transceiver adopts the zero intermediate frequency scheme. The downlink working process of the radio frequency transceiver is as follows: the digital-to-analog converter DAC converts baseband digital signals into analog signals, the analog signals are subjected to up-mixing by a second mixer with local oscillation signals of 2140MHz, the signals are filtered by filters with corresponding working frequency bands and working bandwidths and then are connected with power amplifiers with corresponding working frequency bands, radio-frequency signals are amplified, the amplified signals are connected with the first radio-frequency switch 600 through an isolator, and finally the amplified signals are transmitted out through the antenna 100 through a downlink channel of a duplexer with corresponding working frequency bands. The uplink working process of the radio frequency transceiver is as follows: after being received by the antenna 100, the wireless signal is directly transmitted to the low noise amplifier through the duplexer corresponding to the working frequency band to be amplified, the amplified signal is transmitted to the filter corresponding to the working frequency band and the working bandwidth, then the amplified signal is down-mixed through the first mixer with the local oscillation signal of 1940MHz, and the down-mixed analog signal is converted into a baseband digital signal through the analog-to-digital converter (ADC). In this embodiment, in the LTE radio frequency transceiver circuit compatible with TDD and FDD of the present invention, the first interface and the second interface of the first selection component 210, the second selection component 220, the third selection component 230, the fourth selection component 240, the fifth selection component 250, the sixth selection component 260, and the seventh selection component 270 are connected, the fourth pad in the selection component is welded with a radio frequency path capacitor, the stitch bonding pad technology is adopted, the filter is default, and the first radio frequency switch 600, the second radio frequency switch 700, and the corresponding 50 ohm load are default. Meanwhile, in this embodiment, the multiplexing of multiple operating frequency bands applied in the FDD mode can be realized by changing functional module devices which are packaged with different operating frequency bands and operating bandwidths at each selected component interface.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.