CN218570207U - Directional coupler circuit, directional coupler and microwave device - Google Patents
Directional coupler circuit, directional coupler and microwave device Download PDFInfo
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- CN218570207U CN218570207U CN202223097299.6U CN202223097299U CN218570207U CN 218570207 U CN218570207 U CN 218570207U CN 202223097299 U CN202223097299 U CN 202223097299U CN 218570207 U CN218570207 U CN 218570207U
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Abstract
The utility model provides a directional coupler circuit, directional coupler and microwave device, the circuit includes: a coupling module having an isolated port and a coupled output port; the correction module comprises a first correction module and a second correction module, the first correction module is connected in series on the first branch to form a first output port, and the second correction module is connected in series on the second branch to form a second output port; the first correction module and the second correction module respectively comprise at least one digital phase shifting unit, each digital phase shifting unit comprises a capacitor and a microwave switch, one end of the capacitor is grounded after the capacitor is connected with the microwave switch in series, the other end of the capacitor is connected to the corresponding branch, and the size of the capacitor is adjusted by controlling the on-off of the microwave switch so as to correct the phase difference between the through output port and the coupling output port. The utility model discloses can realize that the phase difference between first output port and the second output port is 90 degrees or 180 degrees.
Description
Technical Field
The utility model relates to a microwave technical field especially relates to a directional coupler circuit, directional coupler and microwave device.
Background
The microwave directional coupler is an important key component in a modern wireless communication system, and can provide a plurality of paths of signals meeting specific amplitude and phase relations for various microwave components. Among the various types of specific phase relationships, the most important type is the 90 (or 180) degree phase relationship signal provided by the microwave 90 (or 180) degree directional coupler, such as the devices of an I/Q quadrature mixer, a differential amplifier, a frequency multiplier, a wave detector, and the like, the performance of which is greatly influenced by the phase relationship of the 90 (or 180) degree signal.
In the actual working environment of the microwave coupler, due to factors such as working frequency band variation, input/output termination impedance fluctuation, additional phase shift of a cascade transmission line and the like, the microwave coupler is generally difficult to provide an ideal 90 (or 180) degree phase relationship for two output signals, so that the performances of orthogonality, image rejection, local oscillation rejection, power synthesis efficiency of a differential amplifier, fundamental wave rejection of a frequency multiplier, detector efficiency and the like of an I/Q mixer are affected. One conventional method for adjusting the phase of the coupler is to adjust the phase difference of output signals by loading varactors, but it is necessary to provide accurate analog voltages to accurately adjust the phase.
SUMMERY OF THE UTILITY MODEL
The utility model provides a directional coupler circuit, directional coupler and microwave device for solve among the prior art directional coupler and be difficult to provide the problem of the 90 degrees or 180 degrees phase relation of ideal for two way signals of output.
In a first aspect, the present invention provides a directional coupler circuit, the circuit comprising:
a coupling module comprising a first branch having an input port and a pass-through output port and a second branch having an isolated port and a coupled output port;
a correction module comprising a first correction module and a second correction module, the first correction module being connected in series on the first branch to form a first output port, the second correction module being connected in series on the second branch to form a second output port;
the first correction module and the second correction module respectively comprise at least one digital phase shift unit, each digital phase shift unit comprises a capacitor and a microwave switch, one end of the capacitor is grounded after the capacitor is connected with the microwave switch in series, the other end of the capacitor is connected to a corresponding branch, and the capacitor is adjusted by controlling the on and off of the microwave switch so as to correct the phase difference between the through output port and the coupling output port.
In an embodiment of the present invention, when a digital phase shift unit is turned on, the transmission phase of the circuit and the capacitance of the digital phase shift unit have the following relationship:
∠H S ＝-arctan(RCω)；
wherein H s Representing a transfer function, V Out Indicating the value of the output voltage, V In Represents the value of the input voltage, R represents the value of a parasitic resistance on the transmission path, C represents the capacitance value of the digital phase shift unit, s represents the complex frequency, and ω represents the angular velocity.
In an embodiment of the present invention, when the microwave switch of the digital phase shift unit is turned off, the transmission phase of the circuit and the capacitance of the digital phase shift unit have the following relationship:
∠H S ＝-arctan(RCω)＝0。
in an embodiment of the present invention, when the microwave switch of the two digital phase shift units is turned on, the transmission phase of the circuit and the capacitance of the two digital phase shift units have the following relationship:
∠H S ＝-arctan(2RCω)。
the utility model discloses an in the embodiment, the microwave switch is the transistor, the base of transistor is used for connecing external control signal in order to control switching on and turn-off of transistor, the projecting pole ground connection of transistor, the collecting electrode of transistor with the one end of electric capacity is connected, the other termination of electric capacity is on corresponding branch road.
The utility model provides an embodiment, the microwave switch is the transistor, the base of transistor is used for connecing external control signal in order to control switching on and turn-off of transistor, the collecting electrode of transistor connects on corresponding branch road, the projecting pole of transistor with earth behind the electric capacity series connection.
In an embodiment of the present invention, a phase difference between the first output port and the second output port is 90 degrees or 180 degrees.
The utility model discloses an in the embodiment, the quantity that microwave switch in the first correction module switched on with the quantity inequality that microwave switch in the second correction module switched on.
In a second aspect, the present invention further provides a directional coupler, which includes a directional coupler circuit as set forth in any one of the first aspect.
In a third aspect, the present invention also provides a microwave device comprising a directional coupler as set forth in the second aspect.
The utility model provides a directional coupler circuit, directional coupler and microwave device, through the unit that shifts the phase of loading digit on microwave transmission branch road, and through the switching on and turn-off of the microwave switch that the control corresponds the digit unit that shifts the phase, adjust this phase correction unit concatenation capacitance value on microwave transmission branch, with the purpose of the phase difference between the direct output port of realization correction and coupling output port, make the phase difference between first output port and the second output port reach accurate 90 degrees or 180 degrees in the target frequency band.
Drawings
In order to more clearly illustrate the technical solutions of the present invention or the prior art, the following briefly introduces the drawings required for the embodiments or the prior art descriptions, and obviously, the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic diagram of a directional coupler circuit provided by the present invention;
fig. 2 is a schematic diagram of a directional coupler circuit according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a digital phase shift unit according to a first embodiment of the present invention;
fig. 4 is a schematic diagram of a digital phase shift unit according to a second embodiment of the present invention;
fig. 5 is a schematic diagram of adjusting the capacitance value when turning on a transistor according to the present invention;
fig. 6 is a schematic diagram of the present invention without adjusting the capacitance value when turning off a transistor;
fig. 7 is a schematic diagram of adjusting capacitance values when two transistors are turned on according to the present invention.
Detailed Description
To make the objects, technical solutions and advantages of the present invention clearer, the drawings of the present invention are combined to clearly and completely describe the technical solutions of the present invention, and obviously, the described embodiments are some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.
The terms "first," "second," and the like in the description and in the claims, and in the drawings described above, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that the embodiments described herein may be practiced otherwise than as specifically illustrated or described herein.
The technical terms related to the present invention are described below:
a directional coupler is a power coupling (splitting) element with directivity. It is a four-port element, usually composed of two transmission lines of a straight line (main line) and a coupled line (sub line). Some (or all) of the power of the straight line is coupled into the coupled line by a certain coupling mechanism (such as a slit, a hole, a coupled line segment, etc.) between the straight line and the coupled line, and the power is required to be transmitted to only one output port in the coupled line, and no power is output from the other port. If the propagation direction of the wave in the straight-through line becomes opposite to the original direction, the output port for coupling the power in the line and the port without power output will also change accordingly, that is, the coupling (distribution) of the power is directional, and thus is called a directional coupler (directional coupler). Directional couplers are widely used in modern electronic systems as an important component of many microwave circuits.
Due to factors such as operating frequency band variation, input/output termination impedance fluctuation, additional phase shift of a cascade transmission line, and the like, the microwave coupler is generally difficult to provide an ideal 90-degree or 180-degree phase relationship for two output signals, thereby affecting the performance of the I/Q mixer, such as orthogonality, image rejection, local oscillation rejection, power synthesis efficiency of a differential amplifier, fundamental rejection of a frequency multiplier, and efficiency of a detector.
In order to solve the problem that the directional coupler is difficult to provide ideal 90 degrees or 180 degrees phase relation for the two way signals of output among the prior art, the utility model provides a directional coupler circuit, directional coupler and microwave device. The phase correction unit is adjusted to be connected in series with the capacitance value of the microwave transmission branch by loading the digital phase shift unit on the microwave transmission branch and controlling the on and off of the microwave switch corresponding to the digital phase shift unit, so that the purpose of correcting the phase difference between the through output port and the coupling output port is achieved, and the phase difference between the first output port and the second output port can reach 90 degrees or 180 degrees accurately in a target frequency band.
The directional coupler circuit, the directional coupler and the microwave device of the present invention will be described with reference to fig. 1 to 7.
Referring to fig. 1, fig. 1 is a schematic diagram of a directional coupler circuit according to the present invention. A directional coupler circuit comprises a coupling module and a correction module, wherein the correction module is used for correcting the phase difference between two output ends of the coupling module.
Illustratively, the coupling module comprises a first branch having an input port P1 and a through output port a and a second branch having an isolated port P2 and a coupled output port B. After microwave signals are input into the coupling module through the input port P1, the signals are respectively output through the through port A and the coupling output port B, and no signal is output through the isolation port P2 under ideal conditions. Since the phase difference between the through output port a and the coupling output port B is not 90 degrees or 180 degrees, the present invention provides a correction module to solve this problem.
Illustratively, the correction module includes a first correction module connected in series on the first branch to form a first output port P3 and a second correction module connected in series on the second branch to form a second output port P4. The first correction module and the second correction module each include at least one digital phase shifting unit. For example, the first correction module comprises a digital phase-shifting unit 1, a digital phase-shifting unit 2, \8230, and a digital phase-shifting unit m (m is a natural number greater than 0). The second correction module comprises a digital phase shift unit 1', digital phase shift units 2' and 8230, and a digital phase shift unit n (n is a natural number greater than 0), wherein m and n can be equal or unequal, and can be specifically set according to an actual circuit, for example, according to the performance of the input port P1 and the isolation port P2, so that the utility model is not limited to the above.
Each digital phase shift unit comprises a capacitor and a microwave switch, wherein one end of the capacitor is grounded after the capacitor is connected with the microwave switch in series, and the other end of the capacitor is connected to a corresponding branch circuit. The capacitance value connected in series on the corresponding branch is adjusted by controlling the on and off of the microwave switch of the digital phase shift unit on the corresponding branch so as to correct the phase difference between the through output port A and the coupling output port B.
Since the phase difference between the through output port a and the coupled output port B is not 90 degrees or 180 degrees, the phase difference between the through output port a and the coupled output port B needs to be corrected by the correction module so that the phase difference between the first output port P3 and the second output port P4 is 90 degrees or 180 degrees.
It follows that the phase difference between the through output port a and the coupled output port B is different from the phase difference between the first output port P3 and the second output port P4. That is, the phase difference between the first output port P3 and the second output port P4 corrected by the correction module provided by the present invention is 90 degrees or 180 degrees, and the phase difference between the through output port a and the coupling output port B is usually difficult to reach the ideal 90 degrees or 180 degrees.
To sum up, the utility model discloses an use the digital unit that moves that shifts of correction module to adopt digital control signal to open, turn-off the operation to one or more microwave switches and realize the adjustment of output signal phase difference, avoided complicated simulation bias voltage network, reduced circuit complexity and control voltage requirement.
The directional coupler circuit of the present invention is described below with an embodiment.
The first embodiment is as follows:
referring to fig. 2, fig. 2 is a schematic diagram of a directional coupler circuit according to an embodiment of the present invention. A directional coupler circuit includes a coupler and a correction module, wherein the correction module includes a first correction module and a second correction module. The first correction module and the second correction module each include at least one digital phase shifting unit. For example, the first correction module includes m (m is a natural number greater than 0) digital phase shift units, and the second correction module includes n (n is a natural number greater than 0) digital phase shift units.
Each digital phase shift unit comprises a capacitor and a microwave switch, wherein one end of the capacitor is grounded after the capacitor is connected with the microwave switch in series, and the other end of the capacitor is connected to a corresponding branch circuit. The capacitance values connected in series on the corresponding branches are adjusted by controlling the on and off of the microwave switches of the digital phase shift unit to correct the phase difference between the through output port a and the coupling output port B, so that the phase difference between the first output port P3 and the second output port P4 is 90 degrees or 180 degrees.
Illustratively, as shown in fig. 3, each digital phase shift unit includes a capacitor C and a transistor B, a base of the transistor B is used for receiving an external control signal to control on and off of the transistor B, an emitter of the transistor B is grounded, a collector of the transistor B is connected to one end of the capacitor C, and the other end of the capacitor C is connected to the corresponding branch.
For example, fig. 2 shows a digital phase shift unit in the first branch, which includes a capacitor C1 and a transistor B1, wherein a base of the transistor B1 is used for receiving an external control signal to control on and off of the transistor B1, an emitter of the transistor B1 is grounded, a collector of the transistor B1 is connected to one end of the capacitor C1, and the other end of the capacitor C1 is connected to the first branch.
For another example, a digital phase shift unit in the second branch includes a capacitor C1 'and a transistor B1', a base of the transistor B1 'is used for receiving an external control signal to control on and off of the transistor B1', an emitter of the transistor B1 'is grounded, a collector of the transistor B1' is connected to one end of the capacitor C1', and the other end of the capacitor C1' is connected to the second branch.
In another embodiment of the present invention, as shown in fig. 4, each digital phase shift unit includes a capacitor C and a transistor B, the base of the transistor B is used for receiving an external control signal to control the on and off of the transistor B, the collector of the transistor B is connected to the corresponding branch, and the emitter of the transistor B is connected to the ground after being connected to the capacitor C in series.
Fig. 3 and 4 show two structures of the digital phase shift unit, which can adjust the size of the capacitor C connected in series to the corresponding branch by controlling the on and off of the transistor B.
Illustratively, the working principle of adjusting the capacitance values connected in series on the corresponding branches by controlling the on and off of the microwave switches of the digital phase shift unit is as follows:
referring to fig. 5, fig. 5 is a schematic diagram of adjusting a capacitance value when a transistor is turned on according to the present invention. When the base of the transistor B of one of the digital phase shift units receives a control voltage of high level, the transistor B is conducted, then the capacitor C of the digital phase shift unit is connected to the directional coupler circuit, and the relation between the transmission phase of the circuit and the capacitor of the digital phase shift unit is as follows:
∠H S ＝-arctan(RCω)；
wherein H S Representing a transfer function, V Out Representing the value of the output voltage, V In Denotes an input voltage value, R denotes a parasitic resistance value on a transmission path, C denotes a capacitance value of a digital phase shift unit, s denotes a complex frequency, ω denotes an angular velocity, ω =2 π f, f denotes an operating frequency of the circuit, and π denotes a circumferential ratio.
As can be seen from the above equation, the transmission phase of the directional coupler circuit is affected by the introduction of the capacitor C, so that the transmission phase can be corrected by adjusting the value of the capacitor C.
Referring to fig. 6, fig. 6 is a schematic diagram of the present invention that the capacitance value is not adjusted when a transistor is turned off, when the base of the transistor of one of the digital phase shift units receives a low control voltage, the transistor is turned off, the capacitor C of the digital phase shift unit is not connected to the directional coupler circuit, and at this time, the parallel capacitor C opens a circuit to the ground and fails, and then the equivalent C =0 in the circuit is obtained after entering the above formula:
∠H S ＝-arctan(RCω)＝0；
at this time, the digital phase shift unit does not affect the transmission phase of the directional coupler circuit.
Referring to fig. 7, fig. 7 is a schematic diagram of adjusting capacitance value when two transistors are turned on according to the present invention, when the bases of the transistors (B1, B2) corresponding to two digital phase shift units all receive a control voltage and are at a high level, the two transistors (B1, B2) are turned on, and then the capacitors (C1, C2) corresponding to the two digital phase shift units are all connected to the directional coupler circuit, and the relationship between the transmission phase of the circuit and the capacitor of the digital phase shift unit is:
∠H S ＝-arctan(2RCω)。
from the derivation, the transmission phase for turning on one transistor B is < H S Is = -arctan (RC omega), and the transmission phase for switching on the two transistors (B1, B2) is & S = arctan (2 RC ω) by varying the value of the capacitance CThe transfer function H can be changed S The phase value of (a). The value of the capacitor C is changed through the number of the transistors B of the conducted digital phase shift unit, the more the transistors B are conducted, the larger the grounding capacitor C is, and the phase value & lt H of the changed transfer function S And therewith becomes larger.
Therefore, by controlling the on and off of the microwave switches of the digital phase shift units of the first correction module and the second correction module, the capacitance values connected in series to the corresponding branches can be adjusted, and according to the formula derived above, the transmission phases of the first output port and the second output port can be adjusted by adjusting the capacitance values, so that the phase difference between the through output port and the coupled output port can be corrected, and the phase difference between the first output port and the second output port can be 90 degrees or 180 degrees.
It should be noted that, as for the microwave switches of how many digital phase shift units need to be turned on by the first correction module and the microwave switches of how many digital phase shift units need to be turned on by the second correction module, the microwave switches may be calculated according to the performance of the input port P1 and the isolation port P2 of the specific microwave transmission line and by the above formula, which is not described herein again.
The embodiment of the utility model provides a still provide a directional coupler, directional coupler can include the directional coupler circuit in above-mentioned arbitrary one embodiment, and the structure of similar part is as shown above, and is not repeated herein.
The embodiment of the utility model provides a microwave device is still provided, microwave device includes the aforesaid directional coupler.
Illustratively, the microwave device may be a microwave oscillator (microwave source), a power amplifier, a mixer, a detector, a microwave antenna, a microwave transmission line, or the like. Through circuit design, can make up these microwave devices into various microwave circuits that have specific functions, for example, utilize these microwave devices can assemble into transmitter, receiver, antenna system, display etc. for electronic equipment such as radar, electronic warfare system and communication system, the embodiment of the utility model provides a do not restrict the type of microwave device.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.
Claims (10)
1. A directional coupler circuit, characterized in that the circuit comprises:
a coupling module comprising a first branch having an input port and a pass-through output port and a second branch having an isolation port and a coupled output port;
a correction module comprising a first correction module and a second correction module, the first correction module being connected in series on the first branch to form a first output port, the second correction module being connected in series on the second branch to form a second output port;
the first correction module and the second correction module respectively comprise at least one digital phase shift unit, each digital phase shift unit comprises a capacitor and a microwave switch, one end of the capacitor is grounded after the capacitor is connected with the microwave switch in series, the other end of the capacitor is connected to a corresponding branch, and the size of the capacitor is adjusted by controlling the on-off of the microwave switch so as to correct the phase difference between the through output port and the coupling output port.
2. The directional coupler circuit of claim 1, wherein when the microwave switch of a digital phase shift unit is turned on, the transmission phase of the circuit is related to the capacitance of the digital phase shift unit by:
∠H s ＝-arctan(RCω)；
wherein H s Representing a transfer function, V Out Indicating the value of the output voltage, V In Represents the value of the input voltage, R represents the value of a parasitic resistance on the transmission path, C represents the capacitance value of the digital phase shift unit, s represents the complex frequency, and ω represents the angular velocity.
3. The directional coupler circuit of claim 2, wherein when the microwave switch of a digital phase shift unit is turned off, the transmission phase of the circuit is related to the capacitance of the digital phase shift unit by:
∠H S ＝-arctan(RCω)＝0。
4. the directional coupler circuit according to claim 2, wherein when the microwave switches of two of the digital phase shift units are turned on, the transmission phase of the circuit is related to the capacitance of the two digital phase shift units by the following equation:
∠H S ＝-arctan(2RCω)。
5. the directional coupler circuit according to claim 1, wherein the microwave switch is a transistor, a base of the transistor is used for receiving an external control signal to control the transistor to be turned on and off, an emitter of the transistor is grounded, a collector of the transistor is connected to one end of the capacitor, and the other end of the capacitor is connected to a corresponding branch.
6. The directional coupler circuit according to claim 1, wherein the microwave switch is a transistor, a base of the transistor is used for receiving an external control signal to control the transistor to turn on and off, a collector of the transistor is connected to the corresponding branch, and an emitter of the transistor is connected in series with the capacitor and then grounded.
7. The directional coupler circuit of claim 1, wherein the phase difference between the first output port and the second output port is 90 degrees or 180 degrees.
8. The directional coupler circuit of claim 1, wherein the number of microwave switches in the first correction module that are turned on is not equal to the number of microwave switches in the second correction module that are turned on.
9. A directional coupler, characterized in that it comprises a directional coupler circuit according to any of claims 1 to 8.
10. A microwave device, characterized in that the microwave device comprises a directional coupler according to claim 9.
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