A reconfigurable duplexer, radio frequency circuit, and communication device

Abstract

The application belongs to the technical field of wireless communication, and particularly relates to a reconfigurable duplexer, a radio frequency circuit and a communication device. The reconfigurable duplexer comprises seven terminal short-circuit half-wavelength microstrip resonators, namely resonator 1, resonator 2, resonator 3, resonator 4, resonator 5, resonator 6 and resonator 7, each of which is loaded with a center short-circuit stub, and the center short-circuit stub is loaded with a fixed capacitor and a variable capacitance diode; the resonator 2, the resonator 3 and the resonator 4 are used to form a first channel, the resonator 5, the resonator 6 and the resonator 7 are used to form a second channel, and the first channel and the second channel share the resonator 1; the application provides a reconfigurable duplexer, which can be flexibly switched between a duplexer function and a filter switch function by adjusting the bias states of the variable capacitance diodes, and the working frequencies of the duplexer mode and the filter switch mode can be continuously adjusted.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication technology, specifically relating to a reconfigurable duplexer, radio frequency circuit, and communication device. Background Technology

[0002] Frequency division duplex (FDM) and time division duplex (TDM) are the two most widely used classic duplex operating modes in modern wireless communication systems. In FDM, the transmit and receive channels can operate simultaneously, but at different frequencies. In TDM, the transmit and receive channels operate at the same frequency, but can only alternate between different time periods. Due to their different operating principles, FDM and TDM have different applicable scenarios. For example, TDM is more advantageous in short-range point-to-point communication and asymmetric transmission applications, while FDM is typically used in communication applications requiring high isolation between transmit and receive channels. Therefore, if a system can flexibly switch between FDM and TDM modes simultaneously, it can effectively improve system flexibility and communication efficiency.

[0003] In the radio frequency (RF) front-end of a communication system, frequency division duplex (FDM) and time division duplex (TDM) modes are typically implemented using a duplexer and a single-pole double-throw (SPD) switch (which is usually cascaded with a preselection filter to filter out out-of-band interference signals), respectively. Therefore, integrating the duplexer and SPD switch together and enabling flexible reconfiguration between them allows the system to have the capability to switch between duplex modes. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, this invention provides a reconfigurable duplexer, a radio frequency circuit, and a communication device.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A reconfigurable duplexer is provided, characterized in that it includes,

[0007] Seven half-wavelength microstrip resonators with short-circuited terminals, namely resonator 1, resonator 2, resonator 3, resonator 4, resonator 5, resonator 6 and resonator 7, are loaded with a center short-circuited stub at the center of each resonator, and a fixed capacitor and a varactor diode are loaded on the center short-circuited stub.

[0008] Resonators 2, 3, and 4 are used to form the first channel, and resonators 5, 6, and 7 are used to form the second channel. The first channel and the second channel share resonator 1.

[0009] The center left side of resonator 1 is connected to the input feed line of port 1 through a varactor diode CV8 and a fixed capacitor CF8. The varactor diode CV8 is controlled by an external bias voltage V8. The center lower side of resonator 4 is connected to the output feed line of port 2 through a varactor diode CV9 and a fixed capacitor CF9. The varactor diode CV9 is controlled by an external bias voltage V11. The center upper side of resonator 7 is connected to the output feed line of port 3 through a varactor diode CV10 and a fixed capacitor CF10. The varactor diode CV10 is controlled by an external bias voltage V12.

[0010] Preferably, resonator 1 and resonator 2 are connected by a pair of back-to-back varactor diodes CV121 and CV122. The cathodes of varactor diodes CV121 and CV122 are connected to the same pad and are externally biased by a voltage V9.

[0011] Preferably, resonator 1 and resonator 5 are connected by a pair of back-to-back varactor diodes CV151 and CV152. The cathodes of varactor diodes CV151 and CV152 are connected to the same pad and are externally biased by a voltage V10.

[0012] Preferably, resonator 2 and resonator 3 are connected by a fixed capacitor CF23.

[0013] Preferably, resonator 3 and resonator 4 are connected by a fixed capacitor CF34.

[0014] Preferably, resonator 5 and resonator 6 are connected by a fixed capacitor CF56.

[0015] Preferably, resonator 6 and resonator 7 are connected by a fixed capacitor CF67.

[0016] Preferably, a 100k ohm fixed resistor is connected in series in the bias voltage path.

[0017] A radio frequency circuit,

[0018] Includes a reconfigurable duplexer as described in claim 8.

[0019] A communication device,

[0020] Includes a reconfigurable duplexer as described in claim 8.

[0021] This invention provides a reconfigurable duplexer, a radio frequency circuit, and a communication device. The beneficial effects of this invention are as follows:

[0022] First, the present invention integrates duplexer and filter switch functions into a single circuit through ingenious structural design. By adjusting the bias state of the varactor diode in the circuit, flexible switching between duplexer mode and filter switch mode can be achieved. At the same time, the operating frequency of the two modes can also be continuously tuned, which has extremely high flexibility and degree of freedom.

[0023] Secondly, the present invention adopts a full resonator structure, which does not require an additional impedance matching network, and has the advantages of compact structure and small circuit area. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall circuit structure of the present invention;

[0025] Figure 2 This is a circuit dimension diagram of the present invention;

[0026] Figure 3 This is a schematic diagram of the S-parameter simulation and test results when the frequency of channel 1 and channel 2 is fixed according to the present invention;

[0027] Figure 4 This is a schematic diagram of the S-parameter simulation and test results when the frequency of channel 2 is fixed when channel 1 is tuned to channel 2 according to the present invention;

[0028] Figure 5 This is a schematic diagram of the S-parameter simulation and test results when channel 1 is open and channel 2 is closed according to the present invention;

[0029] Figure 6 This is a schematic diagram of the S-parameter simulation and test results when channel 2 is open and channel 1 is closed according to the present invention;

[0030] Figure 7 This is a physical image of the present invention. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Please see Figures 1-7 As shown, the specific embodiments provided by the present invention are as follows:

[0033] Example 1:

[0034] like Figure 1As shown, the main body of this application consists of seven short-circuited half-wavelength microstrip resonators. Each resonator has a center short-circuited stub at its center, on which a fixed capacitor and a varactor diode are loaded to adjust the resonant frequency. The seven resonators form two channels, namely the first channel and the second channel, corresponding to channel 1 and channel 2 in the figure. Resonator 1 is a shared resonator for both channel 1 and channel 2. Its center left side is connected to the input feed line of port 1 through a varactor diode CV8 and a fixed capacitor CF8. The varactor diode CV8 is controlled by an external bias voltage V8 and is used to control the input external coupling strength.

[0035] Resonators 2, 3, and 4 are used to form channel 1. The lower center of resonator 4 is connected to the output feed line of port 2 through a varactor diode CV9 and a fixed capacitor CF9. The varactor diode CV9 is controlled by an external bias voltage V11 and is used to control the external coupling strength of the output.

[0036] Resonators 5, 6, and 7 are used to form channel 2. The upper center of resonator 7 is connected to the output feed line of port 3 through a varactor diode CV10 and a fixed capacitor CF10. The varactor diode CV10 is controlled by an external bias voltage V12 and is used to control the external coupling strength of the output.

[0037] Resonator 1 and resonator 2 are connected by a pair of back-to-back varactor diodes CV121 and CV122. Their cathodes are connected to the same pad and are externally biased by a bias voltage V9, which controls the coupling strength between resonator 1 and resonator 2.

[0038] Resonator 1 and resonator 5 are connected by a pair of back-to-back varactor diodes CV151 and CV152. Their cathodes are connected to the same pad and are externally biased by a bias voltage V10, which controls the coupling strength between resonator 1 and resonator 5.

[0039] Resonators 2 and 3 are positioned close to each other at a certain distance and connected by a fixed capacitor CF23. Resonators 3 and 4 are positioned close to each other at a certain distance and connected by a fixed capacitor CF34. Resonators 5 and 6 are positioned close to each other at a certain distance and connected by a fixed capacitor CF56. Resonators 6 and 7 are positioned close to each other at a certain distance and connected by a fixed capacitor CF67. To prevent RF signals from leaking from the bias voltage network, a 100kΩ fixed resistor is connected to each bias voltage path.

[0040] In this embodiment, when the reconfigurable duplexer is working normally, the signal is input from port 1, transmitted to the resonator via the feed line, and finally output from ports 2 and 3 via the feed line. By reasonably adjusting the bias state of each varactor diode in the circuit, it can be made to operate in duplexer mode or filter-switching mode. When the reconfigurable duplexer operates in duplexer mode, channels 1 and 2 are simultaneously on, but the operating frequencies of the two channels are different. When the reconfigurable duplexer operates in filter-switching mode, that is, channels 1 and 2 have the same operating frequency, but only one channel is on at any given time.

[0041] This invention employs a combination of varactor diode tuning technology and microstrip technology. The substrate material is Rogers 6010 with a thickness of 1.27 mm. In this embodiment, the varactor diodes are all MACOM MA46H202 model varactor diodes, and the fixed capacitors are all surface mount capacitors with package type 0402.

[0042] In this embodiment of the invention, an external bias voltage is used to control the capacitance of the varactor diodes. By reasonably setting the bias state of each varactor diode, flexible switching between duplex mode and filter switching mode, as well as continuous adjustment of the operating frequency of the two modes, are achieved. Specifically, varactor diodes CV1, CV2, CV3, CV4, CV5, CV6, and CV7 are used to control the resonant frequency of the resonator. Varactor diodes CV8, CV9, and CV10 are used to control the input-output coupling. Varactor diodes CV121, CV122, CV151, and CV152 are used to control the coupling strength between resonator 1 and resonator 2, as well as between resonator 5.

[0043] like Figure 2 As shown, the optimal circuit size parameters obtained after simulation optimization design are: W1 = 1mm, S12 = 0.8mm, S23 = 0.3mm, S34 = 0.1mm, S15 = 0.1mm, S56 = 0.2mm, S67 = 0.2mm.

[0044] In one alternative embodiment, the overall length of resonator 1 is 24 mm, the overall lengths of resonators 2, 3, and 4 are all 20 mm, and the overall lengths of resonators 5, 6, and 7 are all 24 mm.

[0045] Figures 3-4 The simulation test results of the S-parameter amplitude of the present invention in duplexer mode are presented. Figures 4-5The simulation test results of the S-parameter amplitude of the present invention in the filter switching mode are shown. In the figure, |S11| represents the reflection coefficient of port 1, |S21| represents the transmission coefficient from port 1 to port 2, |S31| represents the transmission coefficient from port 1 to port 3, and |S32| represents the transmission coefficient from port 2 to port 3. The solid line is the measured curve, and the dashed line is the simulated curve. Figures 3-6 It can be seen that this invention can operate in both standard duplexer mode and filter-switching mode. In duplexer mode, such as... Figure 3 As shown, when the center frequency of channel 2 is fixed at 1.55 GHz, the operating frequency of channel 1 can be continuously adjusted from 1.75 GHz to 1.96 GHz, corresponding to an insertion loss change of 3.75 dB to 4.24 dB. Figure 4 As shown, when the center frequency of channel 1 is fixed at 1.75 GHz, the operating frequency of channel 2 can be continuously adjusted from 1.32 GHz to 1.55 GHz, corresponding to an insertion loss change of 4.36 dB to 5.18 dB. Throughout the tuning process, the isolation between the two channels remains above 25.7 dB. In filter-switching mode, as... Figures 5-6 As shown, the operating frequencies of both channels can be continuously adjusted from 1.42 GHz to 1.89 GHz, with passband insertion loss varying between 4.01 dB and 5.5 dB. Therefore, this invention cleverly integrates duplexer and filter switching functions into a single circuit through structural design. By adjusting the bias state of the varactor diode in the circuit, flexible switching between duplexer mode and filter switching mode can be achieved. Simultaneously, the operating frequencies of the two modes can be continuously tuned, exhibiting extremely high flexibility and degree of freedom in reconfiguration.

[0046] This invention is not limited to the above-described embodiments. If any modifications or variations to the invention do not depart from the spirit and scope of the invention, and if such modifications and variations fall within the scope of the claims and equivalent technologies of the invention, then the invention also intends to include such modifications and variations.

[0047] In the description of the embodiments of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "center", "top", "bottom", "top", "bottom", "inner", "outer", "inner side", "outer side", etc. indicate the orientation or positional relationship.

[0048] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "assembly" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0049] In the description of embodiments of the present invention, specific features, structures, materials or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0050] In the description of the embodiments of the present invention, it should be understood that "-" and "~" represent a range of two values, and this range includes the endpoints. For example, "AB" represents a range greater than or equal to A and less than or equal to B. "A~B" represents a range greater than or equal to A and less than or equal to B.

[0051] In the description of embodiments of the present invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0052] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A reconfigurable duplexer, characterized in that, include, Seven half-wavelength microstrip resonators with short-circuited terminals, namely resonator 1, resonator 2, resonator 3, resonator 4, resonator 5, resonator 6 and resonator 7, are loaded with a center short-circuited stub at the center of each resonator, and a fixed capacitor and a varactor diode are loaded on the center short-circuited stub. Resonators 2, 3, and 4 are used to form the first channel, and resonators 5, 6, and 7 are used to form the second channel. The first channel and the second channel share resonator 1. The center left side of resonator 1 is connected to the input feed line of port 1 through a varactor diode CV8 and a fixed capacitor CF8. The varactor diode CV8 is controlled by an external bias voltage V8. The center lower side of resonator 4 is connected to the output feed line of port 2 through a varactor diode CV9 and a fixed capacitor CF9. The varactor diode CV9 is controlled by an external bias voltage V11. The center upper side of resonator 7 is connected to the output feed line of port 3 through a varactor diode CV10 and a fixed capacitor CF10. The varactor diode CV10 is controlled by an external bias voltage V12. Resonator 1 and resonator 2 are connected by a pair of back-to-back varactor diodes CV121 and CV122. The cathodes of varactor diodes CV121 and CV122 are connected to the same pad and are externally biased by voltage V9. Resonator 1 and resonator 5 are connected by a pair of back-to-back varactor diodes CV151 and CV152. The cathodes of varactor diodes CV151 and CV152 are connected to the same pad and are externally biased by voltage V10. By adjusting the bias state of the varactor diode, the reconfigurable duplexer can operate in either duplexer mode or filter switch mode. When the reconfigurable duplexer operates in duplexer mode, the first and second channels are simultaneously on, but their operating frequencies are different. When the reconfigurable duplexer operates in filter switch mode, the first and second channels have the same operating frequency, but only one channel is on at any given time.

2. A reconfigurable duplexer according to claim 1, characterized in that, Resonator 2 and resonator 3 are connected by a fixed capacitor CF23.

3. A reconfigurable duplexer according to claim 2, characterized in that, Resonator 3 and resonator 4 are connected by a fixed capacitor CF34.

4. A reconfigurable duplexer according to claim 3, characterized in that, Resonator 5 and resonator 6 are connected by a fixed capacitor CF56.

5. A reconfigurable duplexer according to claim 4, characterized in that, Resonator 6 and resonator 7 are connected by a fixed capacitor CF67.

6. A reconfigurable duplexer according to claim 5, characterized in that, A 100k ohm fixed resistor is connected in series in the bias voltage path.

7. A radio frequency circuit, characterized in that, Includes a reconfigurable duplexer as described in claim 6.

8. A communication device, characterized in that, Includes a reconfigurable duplexer as described in claim 6.

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