Directional coupler and radio frequency chip

Abstract

The utility model provides a directional coupler and a radio frequency chip, and relates to the technical field of electronic communication. The directional coupler comprises an input port, an output port, a coupling port, an isolation port and an impedance adjusting network, the impedance adjusting network comprises an access switch, an impedance adjusting module and an inductance unit. The impedance adjusting module comprises an adjustable resistor unit and an adjustable capacitor unit which are connected in parallel; one end of the impedance adjusting module is connected to the isolation port through the access switch, and the other end of the impedance adjusting module is connected to the inductance unit; wherein the inductance unit is used for compensating parasitic capacitance in the directional coupler. According to the scheme, the impedance matching and phase characteristics of the directional coupler can be adjusted according to different working frequencies and environmental conditions through mutual cooperation of the access switch, the impedance adjusting module and the inductance unit, so that the directional coupler can maintain good directivity under various working conditions.

Description

Technical Field

[0001] This application relates to the field of electronic communication technology, and more specifically to a directional coupler and a radio frequency chip. Background Technology

[0002] A directional coupler is a device used for radio frequency signal coupling and power detection. Its main function is to couple a portion of the power from the main signal path for measurement, monitoring, or other signal processing, while minimizing the impact on the main signal transmission characteristics. In related technologies, a directional coupler includes an input port, an output port, a coupling port, and an isolation port. To improve the directivity of the directional coupler, an appropriate impedance can be matched at the isolation port to reduce signal reflection and improve isolation.

[0003] However, due to factors such as manufacturing process and parasitic effects, the impedance of the isolation port may deviate from the optimal matching state as the frequency or operating environment changes, resulting in a decrease in the directivity of the directional coupler. Utility Model Content

[0004] Several embodiments in this application provide a directional coupler and an RF chip, which can improve the directionality of the directional coupler to a certain extent.

[0005] In a first aspect, embodiments of this application provide a directional coupler, including an input port, an output port, a coupling port, an isolation port, and an impedance adjustment network; wherein, the impedance adjustment network includes an access switch, an impedance adjustment module, and an inductor unit; the impedance adjustment module includes an adjustable resistor unit and an adjustable capacitor unit connected in parallel; one end of the impedance adjustment module is connected to the isolation port through the access switch; the other end of the impedance adjustment module is connected to the inductor unit; wherein, the inductor unit is used to compensate for parasitic capacitance in the directional coupler.

[0006] Optionally, a first isolation port and a second isolation port electrically connected to the isolation port are symmetrically arranged on both sides of the isolation port; the impedance adjustment network includes a first impedance adjustment network and a second impedance adjustment network symmetrically arranged, and the first impedance adjustment network and the second impedance adjustment network are respectively connected to the first isolation port and the second isolation port.

[0007] Optionally, a connection switch is provided between the isolation port and the coupling port. The connection switch is used to connect to the second impedance adjustment network for forward coupling, or to connect to the first impedance adjustment network for reverse coupling.

[0008] Optionally, the connection switch includes a first connection switch and a second connection switch symmetrically arranged; wherein, the first connection switch is arranged on the same side as the first impedance adjustment network and is used to connect to the second impedance adjustment network for forward coupling; the second connection switch is arranged on the same side as the second impedance adjustment network and is used to connect to the first impedance adjustment network for reverse coupling.

[0009] Optionally, the first connection switch and the second connection switch each include a first T-type switch and a second T-type switch; wherein, the two switch terminals of the first T-type switch are respectively connected to the first isolation port and the coupling port, the two switch terminals of the second T-type switch are respectively connected to the second isolation port and the coupling port, and the common terminal of the first T-type switch and the second T-type switch is grounded.

[0010] Optionally, when the first connection switch is closed and the second connection switch is open, and the access switch of the first impedance adjustment network is open and the access switch of the second impedance adjustment network is closed, the first connection switch is connected to the second impedance adjustment network to achieve forward coupling; or, when the first connection switch is open and the second connection switch is closed, and the access switch of the first impedance adjustment network is closed and the access switch of the second impedance adjustment network is open, the second connection switch is connected to the first impedance adjustment network to achieve reverse coupling.

[0011] Optionally, the adjustable resistor unit includes m resistor elements connected in series, the resistance value of each resistor element increases in binary multiples, and each resistor element is connected in parallel with its corresponding switch element to control the connection state of the corresponding resistor element, where m is a positive integer.

[0012] Optionally, the adjustable capacitor unit includes n capacitor elements connected in parallel, the capacitance value of each capacitor element increases in binary multiples, and each branch containing a capacitor element is provided with a series-connected switching element to control the connection state of the corresponding capacitor element, where n is a positive integer.

[0013] Optionally, the inductor unit includes at least one inductor element; one end of the inductor element is connected to the impedance adjustment module, and the other end is grounded, for compensating for the parasitic capacitance generated by the connection switch.

[0014] Optionally, the input port is used to receive radio frequency signals from the power amplifier, and the output port is used to output radio frequency signals through a filter.

[0015] Secondly, embodiments of this application provide a radio frequency chip, the radio frequency chip including the directional coupler as described in the first aspect.

[0016] In several embodiments provided in this application, one end of the impedance adjustment module is connected to the isolation port via an access switch, which can dynamically adjust the impedance of the isolation port to maintain good impedance matching and improve isolation. The other end of the impedance adjustment module is connected to an inductor unit, which can compensate for parasitic capacitance in the directional coupler, reduce phase deviation, and further improve directivity. Through the cooperation between the access switch, the impedance adjustment module, and the inductor unit, the directional coupler can maintain good directivity under different operating conditions. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a directional coupler in related technologies.

[0019] Figure 2 This is a schematic diagram of a circuit structure for improving the directionality of a directional coupler in related technologies.

[0020] Figure 3 This is a schematic diagram of a directional coupler provided for one embodiment of this application.

[0021] Figure 4 A circuit schematic diagram of a directional coupler is provided for one embodiment of this application.

[0022] Figure 5 A circuit diagram of an impedance adjustment module provided for one embodiment of this application.

[0023] Figure 6 A circuit diagram for compensating parasitic capacitance in an inductor is provided as an embodiment of this application. Detailed Implementation

[0024] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0025] In the description of the embodiments of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0026] A directional coupler is an important microwave component widely used in radio frequency (RF) communication systems. Its primary function is to couple a portion of the power from the main signal channel for power regulation, monitoring, or sampling. In the RF transceiver front-end (TRX), a directional coupler can couple a portion of the power amplifier (PA) output power and use it as a reference signal for power regulation. The basic structure of a directional coupler includes two or more parallel transmission lines (such as microstrip lines or waveguides). The input signal propagates through the main transmission line, while a portion of the signal is electromagnetically coupled to another transmission line, thus achieving power distribution. However, in practical applications, due to manufacturing processes and parasitic effects, the impedance of the isolation port is difficult to adapt to changes in frequency and operating environment. It cannot maintain optimal matching with frequency and environmental variations, leading to increased signal reflection and phase distortion, thereby reducing the isolation and directivity of the directional coupler.

[0027] Please see Figure 1 , Figure 1 A schematic diagram of a directional coupler in related technologies is shown. In this embodiment, the directional coupler adopts a four-port structure, including an input port 1, an output port 2, an isolation (ISO) port 3, and a coupling (CPL) port 4. Transmission lines 1-2 are the main transmission lines, and transmission lines 3-4 are the coupling lines. After the power signal is input from the input port 1, most of the power is directly transmitted to the output port 2 via the main transmission line, while the remaining power is coupled to the coupling lines 3-4 through electromagnetic coupling. The power distribution of the directional coupler is directional: in the same-direction coupling mode, port 4 acts as the coupling port and outputs a signal, while port 3 acts as the isolation port and has no signal output; in the opposite-direction coupling mode, port 3 acts as the coupling port and outputs a signal, while port 4 acts as the isolation port and has no signal output.

[0028] When a directional coupler employs a four-port network structure, the signal transmission characteristics between the ports can be represented by scattering (S) parameters. The S-parameter matrix describes the transmission and reflection characteristics of signals between different ports. For a four-port directional coupler, the S-parameter matrix is ​​expressed as:

[0029]

[0030] Among them, S ij This represents the reflection or transmission of signals sent from port i and received at port j, reflecting the transmission and reflection efficiency between ports, where i, j = 1, 2, 3, 4. If the network structure is ideally lossless, i.e., there is no signal loss or distortion, then according to the input power conservation, S... 2 11 +S 2 12 +S 2 13 +S 2 14 =1.

[0031] Ideal signal transmission requires that the impedances of the transmitting and receiving ports be identical. If they are inconsistent, signal reflection will increase. The reflection coefficient is a measure of this reflection level; a higher reflection coefficient indicates more signal reflection and poorer transmission performance. Ideally, the reflection coefficient of each port should be S. 11 =S 22 =S 33 =S 44 =0, the port matching directly affects directivity. If there is a large impedance mismatch at the isolation port, a large amount of signal will be reflected to the coupling port, resulting in a significant reduction in the electrical coupling energy of the isolation port and an imbalance in the magnetic coupling energy, thus affecting isolation and directivity. In practical applications, due to the parasitic RLC of circuit devices, substrates, etc., the impedance of the isolation port may deviate from the ideal value. If a fixed impedance is directly connected, it may cause the directivity of the directional couplers in different chips to be different, thus affecting signal transmission performance.

[0032] The directivity of a directional coupler can be effectively improved by adjusting the electromagnetic energy distribution within its operating frequency band. For example, connecting an impedance tuning network or filter circuit to the isolation port helps improve impedance matching at the isolation port, reduces signal reflection, and thus enhances the directivity of the directional coupler. Please refer to [link to details]. Figure 2 , Figure 2 This is a circuit structure in related technologies for improving the directivity of directional couplers. Figure 2In this circuit, the directional coupler includes a first microstrip line 21, a second microstrip line 22 coupled to the first microstrip line 21, a first filter unit 23 (using a capacitor-tuned network C1, C2, L1), and a second filter unit 24 (using an inductor-tuned network L2, L3, C3) connected in parallel with the first filter unit 23. One end of the first filter unit 23 is connected to the isolation port, and the other end is grounded through a resistor R, thereby providing the characteristic impedance required for the isolation port. However, in the actual optimization of directivity, due to limitations in manufacturing processes and other factors, the Q (Quality Factor) value of the inductor is relatively low, limiting the optimization effect of the filter unit circuit on directivity. Simultaneously, the output impedance of the power amplifier changes under different output power conditions. The directional coupler, with its fixed impedance matching design, cannot adjust the impedance of the isolation port under different operating conditions, leading to increased signal reflection and aggravated phase distortion, thus reducing the isolation and directivity of the directional coupler and consequently affecting the stability of signal transmission.

[0033] Therefore, given the shortcomings of existing directional couplers in terms of directionality optimization, it is necessary to provide a new directional coupler design that can maintain better isolation and directionality under different operating conditions, thereby improving the stability of signal transmission.

[0034] Please see Figure 3 , Figure 3 A directional coupler is provided as an embodiment of this application. The directional coupler includes an input port 1, an output port 2, a coupling port 4, an isolation port 3, and an impedance adjustment network 300. The impedance adjustment network 300 includes an access switch 301, an inductor unit 304, and an impedance adjustment module. The impedance adjustment module includes an adjustable resistor unit 302 and an adjustable capacitor unit 303 connected in parallel. One end of the impedance adjustment module is connected to the isolation port 3 via the access switch 301, and the other end of the impedance adjustment module is connected to the inductor unit 304. The inductor unit 304 is used to compensate for parasitic capacitance in the directional coupler.

[0035] In this embodiment, the impedance adjustment network 300 is used to adjust the impedance matching state of the isolation port 3 to improve the directivity of the directional coupler. The impedance adjustment network 300 includes an access switch 301, an inductor unit 304, and an impedance adjustment module. The access switch 301 controls the connection state between the impedance adjustment module and the isolation port 3, allowing the impedance connected to the isolation port 3 to be adjusted according to different operating modes. The impedance adjustment module includes an adjustable resistor unit 302 with adjustable resistance and an adjustable capacitor unit 303 with adjustable capacitance. The adjustable resistor unit 302 and the adjustable capacitor unit 303 are connected in parallel. The adjustable resistor unit 302 is used to adjust the loss characteristics of the isolation port, while the adjustable capacitor unit 303 is used to compensate for the influence of frequency changes on impedance matching, enabling the directional coupler to maintain better isolation and directivity over a wider frequency range. Meanwhile, the other end of the impedance adjustment module is connected to the inductor unit 304. The inductor unit 304 is used to compensate for the parasitic capacitance in the directional coupler, thereby optimizing impedance matching, reducing phase distortion, further improving the directivity of the directional coupler, and thus improving the stability of signal transmission. Specifically, the access switch 301 can be an electronic switch controlled by a digital terminal, such as a field-effect transistor or a PIN diode. The specific switch type can be selected according to actual needs, and this application does not impose any restrictions.

[0036] This embodiment's impedance adjustment module uses a parallel-connected adjustable resistor and adjustable capacitor unit for impedance tuning. Its small size and high flexibility allow for better integrated design. One end of the impedance adjustment module is connected to the isolation port via an access switch, enabling dynamic adjustment of the isolation port's impedance to maintain good impedance matching, thereby reducing signal reflection and improving isolation. The other end of the impedance adjustment module is connected to an inductor unit, which compensates for parasitic capacitance in the directional coupler, solves phase deviation problems, avoids signal distortion caused by phase changes, and further improves the directivity of the directional coupler. This embodiment, through the cooperation of the access switch, impedance adjustment module, and inductor unit, can dynamically adjust impedance matching and phase characteristics according to different operating frequencies and environmental conditions, thereby optimizing the performance of the directional coupler and maintaining good isolation and directivity under various operating conditions.

[0037] In some embodiments, a first isolation port and a second isolation port electrically connected to the isolation port are symmetrically arranged on both sides of the isolation port. The impedance adjustment network includes a first impedance adjustment network and a second impedance adjustment network symmetrically arranged, and the first impedance adjustment network and the second impedance adjustment network are respectively connected to the first isolation port and the second isolation port.

[0038] In this embodiment, the directional coupler adopts a symmetrical structure design, with a first isolation port and a second isolation port electrically connected to the isolation port on both sides. The impedance adjustment network is also symmetrically configured as a first impedance adjustment network and a second impedance adjustment network, respectively connected to the first and second isolation ports, allowing independent impedance adjustment for each isolation port. This symmetrical impedance adjustment network structure can provide impedance adjustment and signal isolation in different directions, thereby supporting bidirectional signal coupling to a certain extent and further optimizing the overall performance of the directional coupler.

[0039] Specifically, with Figure 4 The directional coupler shown is an example. Figure 4 In this directional coupler, a first isolation port and a second isolation port are symmetrically arranged on both sides of the isolation port 3, and both the first and second isolation ports are electrically connected to the isolation port 3. Correspondingly, the impedance adjustment network 300 is also symmetrically configured, including a first impedance adjustment network 310 and a second impedance adjustment network 320. These two impedance adjustment networks are respectively connected to the first and second isolation ports, allowing impedance adjustment of each isolation port to be performed independently. This symmetrical design helps the directional coupler provide balanced impedance matching and signal isolation in different directions, thereby supporting bidirectional signal coupling to a certain extent and further optimizing the performance of the directional coupler.

[0040] In some embodiments, a connection switch is provided between the isolation port and the coupling port. The connection switch is used to connect to the second impedance adjustment network for forward coupling or to the first impedance adjustment network for reverse coupling.

[0041] In this embodiment, a connection switch is provided between the isolation port and the coupling port of the directional coupler. The connection switch is used to control the connection between the isolation port and different impedance adjustment networks, thereby achieving forward or reverse coupling of the signal. Specifically, the connection switch can be switched to connect with the second impedance adjustment network, allowing the transmitted signal to be forward coupled through the connection switch and the second impedance adjustment network; or it can be switched to connect with the first impedance adjustment network, allowing the transmitted signal to be reverse coupled through the connection switch and the first impedance adjustment network. This bidirectional coupling structure can adjust the coupling direction of the signal according to different operating requirements, enabling the directional coupler to maintain good impedance matching and signal isolation under different coupling directions, thereby improving its flexibility and stability. Specifically, the connection switch can be an electronic switch that can be controlled digitally, such as a field-effect transistor or a PIN diode. Through digital control, the connection switch can switch the connection with different impedance adjustment networks, thereby achieving forward or reverse coupling. The specific switch type can be selected according to actual needs, and this application does not impose any restrictions.

[0042] Specifically, with Figure 4 The directional coupler shown is an example. Figure 4 In this directional coupler, a connection switch 330 is provided between the isolation port 3 and the coupling port 4. The connection switch 330 can be switched to connect with the second impedance adjustment network 320, allowing the transmitted signal to be forward-coupled with the second impedance adjustment network 320 through the connection switch 330; or it can be switched to connect with the first impedance adjustment network 310, allowing the transmitted signal to be reverse-coupled with the first impedance adjustment network 310 through the connection switch 330. Through this bidirectional coupling structure design, the directional coupler can adjust the signal coupling direction according to different operating requirements, maintaining good impedance matching and signal isolation during both forward and reverse coupling processes, thereby improving its flexibility and stability.

[0043] In some embodiments, the connection switch includes a first connection switch and a second connection switch symmetrically arranged. The first connection switch is disposed on the same side as the first impedance adjustment network and is used to connect to the second impedance adjustment network for forward coupling; the second connection switch is disposed on the same side as the second impedance adjustment network and is used to connect to the first impedance adjustment network for reverse coupling.

[0044] In this embodiment, the connection switches include a symmetrical first connection switch and a second connection switch. Specifically, the first connection switch is disposed on the same side as the first impedance adjustment network and is used to switch to connection with the second impedance adjustment network, thereby achieving forward coupling of the signal; while the second connection switch is disposed on the same side as the second impedance adjustment network and is used to switch to connection with the first impedance adjustment network, thereby achieving reverse coupling of the signal. Through this symmetrical bidirectional coupling design, the directional coupler can effectively balance the impedance characteristics on the forward and reverse transmission paths, maintaining good impedance matching and signal isolation in different coupling directions. This allows for flexible adjustment of the signal transmission direction according to actual needs, further improving its adaptability and stability.

[0045] Specifically, with Figure 4 The directional coupler shown is an example. Figure 4In this design, the connection switch 330 includes a symmetrical first connection switch 331 and a second connection switch 332, which are respectively disposed on the same side as the first impedance adjustment network 310 and the second impedance adjustment network 320. Specifically, the first connection switch 331 can switch to connect with the second impedance adjustment network 320 to achieve forward coupling of the signal; while the second connection switch 332 can switch to connect with the first impedance adjustment network 310 to achieve reverse coupling of the signal. Through this symmetrical bidirectional coupling structure design, the directional coupler can effectively balance the impedance characteristics on the forward and reverse transmission paths, maintaining good impedance matching and signal isolation in different coupling directions. This allows for flexible adjustment of the signal transmission direction according to actual needs, further improving its adaptability and stability.

[0046] In some embodiments, the first connection switch and the second connection switch respectively include a first T-type switch and a second T-type switch; wherein, the two switch terminals of the first T-type switch are respectively connected to a first isolation port and a coupling port, the two switch terminals of the second T-type switch are respectively connected to a second isolation port and a coupling port, and the common terminal of the first T-type switch and the second T-type switch is grounded.

[0047] In this embodiment, the first and second connection switches respectively include a first T-switch and a second T-switch, each with two switching terminals and a common terminal. The two switching terminals of the first T-switch are connected to a first isolation port and a coupling port, respectively, while the two switching terminals of the second T-switch are connected to a second isolation port and a coupling port, respectively. The common terminal of both the first and second T-switch switches is grounded. The T-switch exhibits low insertion loss and high stability, effectively reducing signal reflection and loss when connected to the isolation and coupling ports. Furthermore, grounding the common terminal of the T-switch helps reduce parasitic capacitance and unnecessary interference, thereby optimizing the isolation and directivity of the directional coupler and improving its signal transmission performance.

[0048] Specifically, with Figure 4 The directional coupler shown is an example. Figure 4In this design, both the first connecting switch 331 and the second connecting switch 332 are T-type switches, namely the first T-type switch and the second T-type switch, respectively. One terminal of the first T-type switch is connected to the first isolation port, and the other terminal is connected to the coupling port 4, with their common terminal grounded. Similarly, one terminal of the second T-type switch is connected to the second isolation port, and the other terminal is connected to the coupling port 4, with their common terminal grounded. The first T-type switch can be forward-coupled to the second impedance adjustment network, and the second T-type switch can be reverse-coupled to the second impedance adjustment network, thereby achieving signal switching between forward and reverse coupling. The on / off action of the T-type switches can be controlled digitally, achieving precise and rapid switching. This structure has low insertion loss and high stability, improving the isolation of the directional coupler. Furthermore, grounding the common terminal of the T-type switches reduces parasitic capacitance and unnecessary interference, further optimizing the isolation and directivity of the directional coupler and improving its signal transmission performance.

[0049] In some embodiments, when the first connection switch is closed and the second connection switch is open, and the access switch of the first impedance adjustment network is open and the access switch of the second impedance adjustment network is closed, the first connection switch and the second impedance adjustment network are connected to achieve positive coupling; or, when the first connection switch is open and the second connection switch is closed, and the access switch of the first impedance adjustment network is closed and the access switch of the second impedance adjustment network is open, the second connection switch and the first impedance adjustment network are connected to achieve reverse coupling.

[0050] Specifically, still based on Figure 4 Taking the directional coupler shown as an example, in this embodiment, the directional coupler has both forward and reverse coupling functions. This bidirectional (forward and reverse) coupling function can be achieved by controlling the on / off state of the connection switch and the access switch through the digital terminal. Specifically, when the first T-type switch is closed and the second T-type switch is open, and the access switch of the first impedance adjustment network is open and the access switch of the second impedance adjustment network is closed, the first T-type switch is connected to the second impedance adjustment network, thereby achieving forward coupling. When the first T-type switch is open and the second T-type switch is closed, and the access switch of the first impedance adjustment network is closed and the access switch of the second impedance adjustment network is open, the second T-type switch is connected to the first impedance adjustment network, thereby achieving reverse coupling. Through precise control of the digital terminal, the directional coupler can flexibly switch between forward and reverse coupling while maintaining good impedance matching, isolation, and signal transmission performance.

[0051] To improve the accuracy and flexibility of the impedance adjustment module and better optimize signal matching, the adjustable resistor unit and the adjustable capacitor unit can each employ multi-level adjustment. In some embodiments, the adjustable resistor unit includes m resistor elements connected in series, with the resistance value of each resistor element increasing in binary multiples. Each resistor element is connected in parallel with its corresponding switching element to control the connection state of the corresponding resistor element, where m is a positive integer. The adjustable capacitor unit includes n capacitor elements connected in parallel, with the capacitance value of each capacitor element increasing in binary multiples. Each branch containing a capacitor element has a corresponding series-connected switching element to control the connection state of the corresponding capacitor element, where n is a positive integer.

[0052] Please refer to the details. Figure 5 , Figure 5 A circuit diagram of an impedance adjustment module according to an embodiment of this application is shown. In this embodiment, both the adjustable resistor unit 302 and the adjustable capacitor unit 303 employ multi-level adjustment. The adjustable resistor unit 302 includes m resistors connected in series, with the resistance values ​​increasing in binary multiples (i.e., the resistance values ​​of each resistor are r, 2r, 4r, ..., 2). m-1 r), and each resistor is connected in parallel with its corresponding switch to control the connection state of the corresponding resistor, where m is a positive integer. Therefore, the adjustable resistance value of the adjustable resistor unit 302 is adjustable from 0 to 2. m r, where r represents the minimum resistance value. The adjustable capacitor unit 303 includes n capacitors connected in parallel, with the capacitance values ​​increasing in binary multiples (i.e., the capacitance values ​​are c, 2c, 4c, ..., 2c). n-1 c) Each branch containing a capacitor has a corresponding switch connected in series with it to control the connection state of the corresponding capacitor, where n is a positive integer. Therefore, the adjustable capacitance value of the adjustable capacitor unit 303 is adjustable from 0 to 2. n c represents the minimum capacitance value. By controlling the on / off state of each switch via digital terminals, the resistance value of the adjustable resistor unit 302 and the capacitance value of the adjustable capacitor unit 303 can be dynamically adjusted, thereby achieving high-precision impedance adjustment, further optimizing isolation port matching, reducing signal reflection, and thus improving the isolation and directivity of the directional coupler.

[0053] From the above analysis, the total impedance expression of the impedance adjustment module is:

[0054] Z R =R;

[0055]

[0056] tanθ=-ωRC;

[0057] Where R represents the total resistance of the impedance adjustment module, C represents the total capacitance of the impedance adjustment module, and θ represents the phase angle. By dynamically adjusting different R and C, the real part (resistance) and imaginary part (reactance) of the isolation port impedance of the directional coupler can be adjusted respectively, thereby enabling the selection of the optimal load value under different control signal configurations to achieve optimal directivity.

[0058] In some embodiments, the inductor unit includes at least one inductor element; one end of the inductor element is connected to the impedance adjustment module, and the other end is grounded, for compensating for the parasitic capacitance generated by the connection switch.

[0059] During operation, the switching circuit may introduce parasitic capacitance, which can adversely affect signal transmission characteristics, especially in high-frequency signal transmission, potentially leading to increased signal reflection or distortion. To mitigate these negative effects, the inductor unit uses inductive elements to compensate for the influence of parasitic capacitance, thereby suppressing unwanted reflections and harmonics in high-frequency signals and optimizing signal transmission quality.

[0060] Please refer to the following for details. Figure 4 and Figure 6 . Figure 6 A circuit diagram illustrating an embodiment of this application for compensating for parasitic capacitance in an inductor is shown. In this embodiment, one end of the coupling line of the directional coupler is connected to the CPL port, and the other end is connected to the ISO port. When the connection switch 330 (or T-switch) is turned off, parasitic capacitance C is introduced. off To compensate for the parasitic capacitance C off An inductor L is connected to one end of the adjustable resistor unit 302 and the adjustable capacitor unit 303, and the other end of the inductor L is grounded. Through the introduction of the inductor L, the parasitic capacitance C can be... off This forms a resonant circuit, thereby effectively compensating for the parasitic capacitance C. off The influence of parasitic capacitance C can be mitigated by setting the inductance value of L to match the resonant frequency with the operating center frequency. off This causes signal reflection and distortion, thus further optimizing the directivity of the directional coupler. The resonance formula is as follows:

[0061]

[0062] Where L represents the inductance value, C0 represents the parasitic capacitance value, and f0 represents the resonant frequency.

[0063] In some embodiments, the input port is used to receive radio frequency signals from the power amplifier, and the output port is used to output radio frequency signals through a filter.

[0064] Please refer to the details. Figure 4In this embodiment, the input port 1 of the directional coupler can be used to receive radio frequency (RF) signals from the PA, which are transmitted to the output port 2 via the main transmission line. The output port 2 is connected to a filter, and the RF signal is output after being processed by the filter. The output RF signal can be used for subsequent applications, such as signal transmission, signal amplification, or further processing.

[0065] In summary, the solutions provided in the above embodiments improve the isolation and directivity of the directional coupler through multi-level impedance adjustment of the adjustable resistor and capacitor units, and their cooperation with the inductor unit. The impedance adjustment module employs a compact multi-level parallel network structure, which facilitates high integration design, offers high accuracy and flexibility, and enables wide-range, high-precision tuning. The impedance adjustment module, in conjunction with the inductor unit, effectively compensates for parasitic capacitance introduced by the connection switch, reduces phase deviation, and further optimizes the directivity of the directional coupler. Combined with the connection switch, the directional coupler can dynamically adjust the impedance of the isolation port, achieving better impedance matching and improving signal transmission quality. Furthermore, through the symmetrical impedance adjustment network and connection switch configuration, the directional coupler supports flexible forward and reverse coupling functions, meeting the needs of different application scenarios and possessing greater flexibility and adaptability.

[0066] This application also provides an RF chip, which includes a directional coupler as described in any of the above embodiments.

[0067] The specific functions and effects of each module in the RF chip can be explained by referring to the aforementioned embodiments, and will not be repeated here.

[0068] This application embodiment also provides a control method for a directional coupler. The directional coupler includes an input port, an output port, a coupling port, an isolation port, and an impedance adjustment network. The impedance adjustment network includes an access switch, an impedance adjustment module, and an inductor unit. The control method includes:

[0069] The control access switch is closed to connect the impedance adjustment module to the isolation port; wherein, the impedance adjustment module is used to control and adjust the impedance of the isolation port, and the inductor unit is used to compensate for the parasitic capacitance in the directional coupler.

[0070] This embodiment achieves dynamic adjustment of the isolation port impedance by connecting an impedance adjustment network to the isolation port of the directional coupler and combining it with an inductor unit to compensate for parasitic capacitance. This optimizes impedance matching, reduces signal reflection, and improves the isolation and directivity of the directional coupler.

[0071] In some embodiments, a first isolation port and a second isolation port are provided symmetrically on both sides of the isolation port; the impedance adjustment network includes a first impedance adjustment network and a second impedance adjustment network that are symmetrically connected to the first isolation port and the second isolation port, respectively; a connection switch is provided between the isolation port and the coupling port; the control method of the directional coupler further includes:

[0072] The control switch connects to the second impedance adjustment network for positive coupling; or,

[0073] The control connection switch is connected to the first impedance adjustment network for reverse coupling.

[0074] In some embodiments, the connection switch includes a symmetrical first connection switch and a second connection switch; wherein the first connection switch is disposed on the same side as the first impedance adjustment network, and the second connection switch is disposed on the same side as the second impedance adjustment network; the control method for the directional coupler further includes:

[0075] Close the first connection switch, open the second connection switch, and close the access switch for the second impedance adjustment network, thus connecting the first connection switch and the second impedance adjustment network to achieve positive coupling; or,

[0076] The second connection switch is closed, the first connection switch is opened, and the access switch of the first impedance adjustment network is closed, so that the second connection switch and the first impedance adjustment network are connected to achieve reverse coupling.

[0077] The specific functions and effects of each step in the method for improving the directionality of the directional coupler can be explained by referring to the aforementioned embodiments, and will not be repeated here.

[0078] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc. can transmit electrical signals or data to each other.

[0079] It is understood that the specific examples in this document are only intended to help those skilled in the art better understand the embodiments of this application, and are not intended to limit the scope of this utility model.

[0080] It is understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0081] It is understood that the various embodiments described in this application can be implemented individually or in combination, and the embodiments of this application are not limited in this respect.

[0082] Unless otherwise stated, all technical and scientific terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items. The singular forms "a," "the," and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0083] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0084] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0085] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0086] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0087] The above description is merely a specific embodiment of this application, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the protection scope of this application. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A directional coupler characterized by, The directional coupler comprises an input port, an output port, a coupling port, an isolation port and an impedance adjustment network; wherein the impedance adjustment network comprises an access switch, an impedance adjustment module and an inductor unit; The impedance adjustment module comprises an adjustable resistance unit and an adjustable capacitance unit connected in parallel; one end of the impedance adjustment module is connected to the isolation port through the access switch; the other end of the impedance adjustment module is connected to the inductor unit; wherein the inductor unit is used to compensate for the parasitic capacitance in the directional coupler.

2. The directional coupler of claim 1, wherein, The isolation port is symmetrically provided with a first isolation port and a second isolation port electrically connected to the isolation port on both sides; the impedance adjustment network comprises a first impedance adjustment network and a second impedance adjustment network symmetrically arranged, and the first impedance adjustment network and the second impedance adjustment network are respectively connected to the first isolation port and the second isolation port.

3. The directional coupler of claim 2, wherein, A connection switch is arranged between the isolation port and the coupling port, and the connection switch is used to be connected with the second impedance adjustment network for forward coupling or to be connected with the first impedance adjustment network for reverse coupling.

4. The directional coupler of claim 3, wherein, The connection switch comprises a first connection switch and a second connection switch symmetrically arranged; wherein The first connection switch is arranged on the same side of the first impedance adjustment network and is used to be connected with the second impedance adjustment network for forward coupling; The second connection switch is arranged on the same side of the second impedance adjustment network and is used to be connected with the first impedance adjustment network for reverse coupling.

5. The directional coupler of claim 4, wherein, The first connection switch and the second connection switch respectively comprise a first T-type switch and a second T-type switch; wherein Two switch ends of the first T-type switch are respectively connected to the first isolation port and the coupling port, two switch ends of the second T-type switch are respectively connected to the second isolation port and the coupling port, and the common ends of the first T-type switch and the second T-type switch are grounded.

6. The directional coupler of claim 1, wherein, The adjustable resistance unit comprises m resistance elements connected in series, the resistance values of the resistance elements are increased in binary multiples, and each resistance element is connected in parallel with a corresponding switch element to control the access state of the corresponding resistance element, wherein m is a positive integer.

7. The directional coupler of claim 1, wherein, The adjustable capacitance unit comprises n capacitance elements connected in parallel, the capacitance values of the capacitance elements are increased in binary multiples, and each capacitance element is provided with a corresponding switch element in series in the branch to control the access state of the corresponding capacitance element, wherein n is a positive integer.

8. The directional coupler of any one of claims 3 to 5, wherein, The inductor unit comprises at least one inductor element; one end of the inductor element is connected to the impedance adjustment module, and the other end is grounded, for compensating for the parasitic capacitance generated by the connection switch.

9. The directional coupler of claim 1, wherein, The input port is used to receive a radio frequency signal from a power amplifier, and the output port is used to output a radio frequency signal through a filter.

10. A radio frequency chip, characterized by The directional coupler comprises an input port, an output port, a coupling port, an isolation port and an impedance adjustment network; wherein the impedance adjustment network comprises an access switch, an impedance adjustment module and an inductor unit; The directional coupler comprises an input port, an output port, a coupling port, an isolation port and an impedance adjustment network; wherein the impedance adjustment network comprises an access switch, an impedance adjustment module and an inductor unit;

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