Balanced broadband phase reconfigurable phase shifter

Abstract

The invention discloses a balanced broadband phase reconfigurable phase shifter, which is characterized in that two sides of ports of two U-shaped coupling microstrip lines are respectively and correspondingly connected with one end of a second microstrip line, and the other end of each second microstrip line is respectively and correspondingly connected with one end of a first microstrip line; the upper ends and the lower ends of the two third microstrip lines are correspondingly connected with the side edges of the first microstrip lines respectively; a pair of variable capacitance diodes are respectively connected in series between the port of each U-shaped coupling microstrip line and the ground in a reverse direction, and a variable capacitance diode of which the anode is grounded is connected in series in a reverse direction at the bottom of each U-shaped coupling microstrip line; by changing the bias voltage of the six variable capacitance diodes, a reconfigurable differential mode phase shift reference value relative to the initial bias voltage can be obtained; the electrical lengths of the two U-shaped coupling microstrip lines, the four second microstrip lines and the two third microstrip lines are used for adjusting the differential mode phase slope so as to realize broadband adjustable differential mode phase shift; meanwhile, the four second microstrip lines and the two third microstrip lines are also used for adjusting the differential mode impedance matching bandwidth.

Description

Technical Field

[0001] The present invention relates to a phase shifter, and particularly to a balanced broadband phase reconfigurable phase shifter. Background Art

[0002] The development trend of multifunction, miniaturization and broadband of wireless communication systems has put forward higher requirements for the anti-environmental noise, electromagnetic crosstalk suppression ability and bandwidth of the terminal circuits of communication systems. As a key radio frequency and microwave device, phase shifters have been widely used in communication, radar and phased array systems. Balanced broadband phase shifters have become a research hotspot in recent years because they have both broadband differential mode phase shift and broadband common mode suppression functions. On the other hand, phase reconfigurable phase shifters can dynamically adjust the phase of the output signal according to actual needs, and their flexibility is particularly important in applications that require multifunction and real-time control. Therefore, a balanced broadband phase shifter with phase reconfigurability conforms to the current development trend of wireless communication systems.

[0003] In recent years, a series of balanced broadband phase shifters that can achieve a relatively wide operating bandwidth and good anti-noise interference ability have been proposed. However, most balanced broadband phase shifters provide fixed phase shift values and do not have the ability of phase reconfiguration. The existing reported balanced phase reconfigurable phase shifters mainly use a multi-layer substrate structure with a liquid crystal layer placed in the middle and a coupled microstrip line structure cascaded with a terminated varactor diode. The existing designs have problems such as narrow operating bandwidth and complex structure. Therefore, it is necessary to propose a broadband and simple-structured balanced phase reconfigurable phase shifter. Summary of the Invention

[0004] Object of the Invention: Aiming at the above-mentioned existing technologies, a balanced broadband phase reconfigurable phase shifter is proposed to solve the problems of narrow operating bandwidth and complex structure existing in existing devices, and has a smaller size.

[0005] Technical Solution: A balanced broadband phase reconfigurable phase shifter includes four feed lines, four first microstrip lines, four second microstrip lines, two U-shaped coupled microstrip lines, and two third microstrip lines; On both sides of the ports of the two U-shaped coupled microstrip lines, they are respectively connected to one end of a horizontally arranged second microstrip line. The other ends of the second microstrip lines are respectively connected to one end of a first microstrip line. The other ends of the first microstrip lines are respectively connected to one end of a feed line through a DC-blocking patch capacitor C b correspondingly; the two third microstrip lines are arranged vertically in parallel, and the upper and lower ends are respectively connected to the sides of a first microstrip line; A pair of varactor diodes with anodes connected in series in reverse are respectively connected between the port of each U-shaped coupled microstrip line and the ground R 2 ofC v1 and a varactor diode with anodic grounding is reversely connected in series at the bottom of each U-shaped coupled microstrip line C v2 ; the varactor diode C v2 is also connected in series with a DC-blocking patch capacitor between the cathode of the varactor diode and the bottom of the U-shaped coupled microstrip line C b ; the cathode is also connected to a third metal patch with an external DC voltage through a resistor R 3 and a fourth microstrip line; A reconfigurable differential-mode phase shift reference value relative to the initial bias voltage is obtained by changing the bias voltages of the six varactor diodes.

[0006] Furthermore, it also includes two microstrip line stubs; the two microstrip line stubs are respectively loaded at the central positions of the two third microstrip lines, and the other ends of the microstrip line stubs are respectively grounded through resistors R 1 to ground.

[0007] Furthermore, the central position of one of the third microstrip lines is also connected to a third metal patch with another external DC voltage through a choke inductor L R to connect.

[0008] Furthermore, the line width of the first microstrip line is the same as that of each feeder line.

[0009] Furthermore, the electrical length of the second microstrip line is 25°, the electrical length of the U-shaped coupled microstrip line is 55°, and the electrical length of the third microstrip line is 148°.

[0010] Beneficial effects: Most of the existing balanced broadband phase shifters have fixed-phase shifting and do not have the ability of phase reconfiguration. And the balanced phase-reconfigurable phase shifters have deficiencies such as narrow operating bandwidth and complex structure. The present invention realizes a balanced broadband phase-reconfigurable phase shifter with broadband differential-mode impedance matching, broadband reconfigurable differential-mode phase shifting, and broadband common-mode suppression through a pair of U-shaped coupled microstrip lines with varactor diodes loaded at specific positions cascaded with four microstrip lines, and a pair of microstrip lines with short-circuit stubs loaded in the middle. Brief Description of the Drawings

[0011] Figure 1 is a schematic structural diagram of the balanced broadband phase-reconfigurable phase shifter of the present invention; Figure 2 is the differential-mode S parameter theoretical response of the balanced broadband phase-reconfigurable phase shifter of the present invention; Figure 3 is the common-mode of the balanced broadband phase-reconfigurable phase shifter of the present inventionS Parameter theoretical response; Figure 4 This is the differential-mode phase shift theoretical response of the balanced broadband phase reconfigurable phase shifter of the present invention. Detailed implementation manners

[0012] The present invention will be further explained below with reference to the accompanying drawings.

[0013] As Figure 1 shown, a balanced broadband phase reconfigurable phase shifter includes four feed lines 1, four first microstrip lines 2, four second microstrip lines 3, two U-shaped coupled microstrip lines 4, two third microstrip lines 5, two microstrip line stubs 6, six ground vias 7, two first metal patches 8, two second metal patches 9, two third metal patches 10 connected to an external DC voltage, one fourth microstrip line 11, six DC-blocking patch capacitors C b , two resistors R 1 , two resistors R 2 , two resistors R 3 , four varactor diodes C v1 , two varactor diodes C v2 , one choke inductor L R .

[0014] Among them, the line widths of the four first microstrip lines 2 are the same as those of the respective feed lines 1. Among the four second microstrip lines 3 arranged horizontally, two are on the upper straight line and the other two are on the lower straight line; the two U-shaped coupled microstrip lines 4 are respectively arranged between the upper two second microstrip lines 3 and between the lower two second microstrip lines 3, and both sides of the ports of the second microstrip lines 3 are respectively connected to one end of a second microstrip line 3; the other ends of the respective second microstrip lines 3 are respectively connected to one end of a first microstrip line 2, and the other ends of the respective first microstrip lines 2 are respectively connected to one end of a feed line 1 through a DC-blocking patch capacitor C b . The two third microstrip lines 5 are arranged vertically in parallel, and the upper and lower ends of the third microstrip lines 5 are respectively connected to the sides of a first microstrip line 2.

[0015] The anodes of the two varactor diodes C v1 are connected to a first metal patch 8, and the cathodes are respectively connected to both ports of a U-shaped coupled microstrip line 4; the anodes of the other two varactor diodes C v1The anode is connected to another first metal patch 8, and the cathodes are respectively connected to the two ports of another U-shaped coupled microstrip line 4; the two first metal patches 8 are respectively connected to a ground via hole 7 through a resistor R 2 connected to a ground via hole 7.

[0016] The two varactor diodes pass through C v2 The anodes are respectively grounded through the ground via holes 7, and the cathodes are respectively connected to a second metal patch 9; the bottoms of the U-shaped coupled microstrip lines 4 are respectively connected to a second metal patch 9 through a DC-blocking patch capacitor C b connected to a second metal patch 9; the two second metal patches 9 are respectively connected to a fourth microstrip line 11 through a resistor R 3 connected to a fourth microstrip line 11, and the fourth microstrip line 11 is connected to a third metal patch 10.

[0017] The two microstrip line stubs 6 are respectively loaded at the central positions of the two third microstrip lines 5, and the other ends of the microstrip line stubs 6 are respectively connected to a ground via hole 7 through a resistor R 1 connected to a ground via hole 7; the central position of one of the third microstrip lines 5 is also connected to another third metal patch 10 through a choke inductor L R connected to another third metal patch 10. For the above structure, except for the choke inductor L R and the third metal patch 10, the rest of the overall structure is symmetric about the horizontal and vertical center line directions.

[0018] In the present invention, by changing the bias voltages of the six varactor diodes, a reconfigurable differential-mode phase shift reference value relative to the initial bias voltage can be obtained; the electrical lengths of the two U-shaped coupled microstrip lines 4, the four second microstrip lines 3, and the two third microstrip lines 5 are used to adjust the differential-mode phase slope to achieve broadband adjustable differential-mode phase shift; at the same time, the electrical lengths of the four second microstrip lines 3 and the two third microstrip lines 5 are also used to adjust the differential-mode impedance matching bandwidth. The two microstrip line stubs 6 are respectively connected in series with a resistor R 1 and grounded, which can improve the common-mode rejection bandwidth without affecting the differential-mode operation.

[0019] The balanced broadband phase reconfigurable phase shifter of this embodiment uses a RO4003C substrate, with a dielectric constant of 3.38, a loss tangent of 0.0027, a thickness of 0.813 mm, the electrical length of the second microstrip line 3 is 25°, the electrical length of the U-shaped coupled microstrip line 4 is 55°, the electrical length of the third microstrip line 5 is 148°, the center frequency is 1.8 GHz, and the varactor diode is of the SMV2019 type, with its C v1，min = 0.3 pF,C v1，max = 0.63 pF, C v2，min = 0.66 pF, C v2，max = 0.97 pF. The simulated differential S parameters, common-mode S parameters, and differential-mode phase shift responses are respectively as Figure 2 , Figure 3 and 4 shown, where C v1 = 0.3 pF, C v2 When = 0.66 pF, the generated phase is the reference phase, and its corresponding 10-dB differential-mode impedance matching bandwidth is 104%, and the 10-dB common-mode rejection bandwidth is 135.6%. When C v1 = 0.42 pF, C v2 = 0.75 pF, the phase shift bandwidth when the phase shift value is 15° and the phase shift error is ±1.2° is 83.3%, the 10-dB differential-mode impedance matching bandwidth is 105%, the minimum insertion loss within the frequency band is 1.3 dB, and the 10-dB common-mode rejection bandwidth is 133.3%. When C v1 = 0.54 pF, C v2 = 0.86 pF, the phase shift bandwidth when the phase shift value is 30° and the phase shift error is ±1.8° is 77.7%, the 10-dB differential-mode impedance matching bandwidth is 103.8%, the minimum insertion loss within the frequency band is 1.35 dB, and the 10-dB common-mode rejection bandwidth is 131.7%. When C v1 = 0.63 pF, C v2 = 0.97 pF, the phase shift bandwidth when the phase shift value is 45° and the phase shift error is ±3° is 83.3%, the 10-dB differential-mode impedance matching bandwidth is 101.1%, the minimum insertion loss within the frequency band is 1.45 dB, and the 10-dB common-mode rejection bandwidth is 130%.

[0020] Compared with the existing balanced phase-reconfigurable phase shifter, the present invention has the advantages of broadband differential-mode impedance matching, broadband reconfigurable differential-mode phase shift, broadband common-mode rejection, and simple structure and easy processing.

[0021] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A balanced broadband phase reconfigurable phase shifter, characterized in that: It comprises four feed lines (1), four first microstrip lines (2), four second microstrip lines (3), two U-shaped coupled microstrip lines (4), and two third microstrip lines (5); Both sides of the ports of the two U-shaped coupling microstrip lines (4) are respectively connected to one end of a second microstrip line (3) arranged horizontally, the other end of each second microstrip line (3) is respectively connected to one end of a first microstrip line (2), and the other end of each first microstrip line (2) is respectively connected to one end of a DC blocking chip capacitor. C b One end of a feeder line (1) is correspondingly connected; two third microstrip lines (5) are arranged in parallel in the vertical direction, and the upper and lower ends are respectively correspondingly connected to the side of a first microstrip line (2); A pair of anode connection resistors are connected in reverse series between the (4) port of each U-shaped coupled microstrip line and the ground. R 2 Varactor diode C v1 , and a varactor diode with a grounded anode is connected in reverse series at the bottom of each U-shaped coupled microstrip line (4). C v2 ; Varactor diode C v2 A DC blocking chip capacitor is connected in series between the cathode and the bottom of the U-shaped coupling microstrip line (4). C b , the cathode is also connected through a resistor R 3 and the fourth microstrip line (11) are connected to a third metal patch (10) which is externally connected to a DC voltage; A reconfigurable differential mode phase shift reference value relative to an initial bias voltage is obtained by changing the bias voltages of six varactor diodes.

2. The balanced broadband phase reconfigurable phase shifter according to claim 1, characterized in that: It also includes two microstrip line branches (6); the two microstrip line branches (6) are respectively loaded at the center positions of the two third microstrip lines (5), and the other ends of the microstrip line branches (6) are respectively connected through resistors R 1 Ground.

3. The balanced broadband phase reconfigurable phase shifter according to claim 2, characterized in that: The center position of one of the third microstrip lines (5) is also connected via a choke inductor. L R A third metal patch (10) is connected to another external DC voltage.

4. The balanced broadband phase reconfigurable phase shifter according to claim 1, characterized in that: The line width of the first microstrip line (2) is consistent with the line width of each feed line (1).

5. The balanced broadband phase reconfigurable phase shifter according to any one of claims 1 to 4, characterized in that: The electrical length of the second microstrip line (3) is 25°, the electrical length of the U-shaped coupling microstrip line (4) is 55°, and the electrical length of the third microstrip line (5) is 148°.

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