A broadband five-bit digital phase shifter based on hybrid microstrip-slotline structure

Abstract

The application discloses a kind of wideband five digit phase shifters based on mixed microstrip line-slot line structure, it is related to mobile communication technical field, including first phase shift unit, second phase shift unit, third phase shift unit, fourth phase shift unit and fifth phase shift unit connected in turn by interconnection microstrip line, second phase shift unit, third phase shift unit and fourth phase shift unit all include four microstrip-slot line switching structure and two single-pole double-throw switch structure, first phase shift unit includes four microstrip-slot line switching structure, two single-pole double-throw switch structure and short-circuit microstrip, fifth phase shift unit includes switch switching microstrip-slot line switching structure.The phase shifter is 11.25 ° as phase shift step value, in the range of 0 ° ~ 360 °, a total of 32 phase shift states can be realized.This application has the advantages that working principle and circuit structure are simple, phase shift precision is good and working bandwidth is wide.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mobile communication technology, in particular to a wideband five-bit digital phase shifter based on a hybrid microstrip-line-slot-line structure. BACKGROUND

[0002] Phase shifter is one of the most important microwave devices, which is widely used in phased array, beam forming network, new smart antenna and phase modulation communication system. By controlling the phase and amplitude of the signal transmitted by each antenna element in the phased array system, the aperture illumination function of the phased array antenna is changed, so as to realize the rapid scanning and shape change of the antenna beam. In order to meet the needs of the phased array system for wideband, large scanning range and high scanning accuracy, the phase shifter with the characteristics of wideband, large phase shift range and high phase shift accuracy has always been the focus of the industry.

[0003] According to whether the phase is continuously adjustable, the phase shifter can be divided into digital phase shifter and analog phase shifter. Among them, the digital phase shifter has the advantages of stable phase shift characteristics, less affected by external factors, etc., and is widely used in phased array systems. The traditional digital phase shifter is realized by high-low network, all-pass network and switch filter network structure, but these structures all face the problems of increasing the bandwidth of the phase shifter depending on the increase of the network order, increasing the influence of inductive parasitic parameters on performance with increasing frequency, etc., and have a relatively complex circuit structure. SUMMARY

[0004] The present application provides a wideband five-bit digital phase shifter based on a hybrid microstrip-line-slot-line structure, which solves the problem of the traditional digital phase shifter depending on the increase of the network order, increasing the influence of inductive parasitic parameters on performance with increasing frequency.

[0005] The present application provides a wideband five-bit digital phase shifter based on a hybrid microstrip-line-slot-line structure, which includes a first phase shift unit, a second phase shift unit, a third phase shift unit, a fourth phase shift unit and a fifth phase shift unit connected in turn through interconnection microstrip lines.

[0006] The first phase shift unit, the second phase shift unit, the third phase shift unit and the fourth phase shift unit each include four microstrip-slot line adapter structures and two single-pole double-throw switch structures, four microstrip-slot line adapter structures are respectively arranged on the upper and lower sides of the two single-pole double-throw switch structures, and the two microstrip-slot line adapter structures on different sides are switched by the single-pole double-throw switch; the two microstrip-slot line adapter structures on the same side are connected by interconnection slot lines.

[0007] The first phase shift unit further includes a short-circuit microstrip line vertically loaded in the middle of the lower interconnection slot line.

[0008] The fifth phase-shifting unit comprises a switchable microstrip-slotline adapter structure, and the switchable microstrip-slotline adapter structure comprises a microstrip line vertically loaded on a slot line.

[0009] The lengths of the two interconnected slot lines on different sides of the first phase-shifting unit, the second phase-shifting unit, the third phase-shifting unit and the fourth phase-shifting unit are different, and the characteristic impedances of the microstrip lines in the microstrip-slotline adapter structures on different sides are different.

[0010] Preferably, the four microstrip-slotline adapter structures comprise a first microstrip-slotline adapter structure, a second microstrip-slotline adapter structure, a third microstrip-slotline adapter structure and a fourth microstrip-slotline adapter structure.

[0011] The topologies of the four microstrip-slotline adapter structures are the same, and each of the topologies comprises:

[0012] A first microstrip line, one end of which is open;

[0013] A first slot line, one end of which is short-circuited.

[0014] Preferably, the topologies of the two SPDT switch structures are symmetrically arranged left and right, and the SPDT switch structure on the left side comprises:

[0015] A first diode, the negative electrode of which is grounded, and the positive electrode of which is connected to the other end of the first microstrip line of the first microstrip-slotline adapter structure;

[0016] A second diode, the positive electrode of which is connected to the output end of the interconnected microstrip line;

[0017] A third diode, the negative electrode of which is connected to the output end of the interconnected microstrip line;

[0018] A fourth diode, the positive electrode of which is grounded, and the negative electrode of which is connected to the other end of the first microstrip line of the third microstrip-slotline adapter structure;

[0019] Two first DC bias resistors, one end of each of which is connected to the other end of the two first microstrip lines of the first microstrip-slotline adapter structure and the third microstrip-slotline adapter structure, respectively;

[0020] Two first DC bias voltages, the outputs of which are interconnected to the other ends of the two first DC bias resistors, respectively.

[0021] Preferably, a first interconnected slot line is arranged between the first microstrip-slotline adapter structure and the second microstrip-slotline adapter structure, the other ends of the two first slot lines of the first microstrip-slotline adapter structure and the second microstrip-slotline adapter structure are interconnected to the two ends of the first interconnected slot line, respectively, and the other ends of the two first microstrip lines are vertically loaded on the two ends of the first interconnected slot line.

[0022] The second microstrip-slotline adapter structure and the fourth microstrip-slotline adapter structure are provided with a second interconnection slotline, and the other ends of the two first slotlines of the third microstrip-slotline adapter structure and the fourth microstrip-slotline adapter structure are respectively interconnected with the two ends of the second interconnection slotline, and the other ends of the two first microstrip lines are both perpendicularly loaded on the two ends of the second interconnection slotline.

[0023] Preferably, the second phase shift unit is a 11.25° phase shift unit, the widths of the first microstrip lines of the first microstrip-slotline adapter structure and the second microstrip-slotline adapter structure are both 1.19 mm, and the widths of the first microstrip lines of the third microstrip-slotline adapter structure and the fourth microstrip-slotline adapter structure are both 1.4 mm; the length and the width of the plurality of first slotlines are both 15 mm and 0.15 mm, the length of the second interconnection slotline is 4 mm, the length of the first interconnection slotline is 7.8 mm, and the plurality of first DC bias resistors are all 2 Kohm, and the plurality of first DC bias voltages are all ±20 V;

[0024] The third phase shift unit is a 22.5° phase shift unit, the length of the second interconnection slotline is 10.6 mm, and the width of the first microstrip line of the third microstrip-slotline adapter structure is 1.65 mm, and the sizes of the rest of the topological structures are the same as those of the 11.25° phase shift unit;

[0025] The fourth phase shift unit is a 45° phase shift unit, the length of the second interconnection slotline is 15.4 mm, the width of the first microstrip line of the first microstrip-slotline adapter structure is 0.9 mm, the width of the first microstrip line of the third microstrip-slotline adapter structure is 1.95 mm, and the sizes of the rest of the topological structures are the same as those of the 11.25° phase shift unit.

[0026] Preferably, the first phase shift unit is a 90° phase shift unit, the negative poles of the two first diodes of the two single-pole double-throw switch structures are both grounded through a first resistor, and the negative poles of the two fourth diodes are both grounded through a second resistor.

[0027] The short-circuit microstrip line is grounded at one end and perpendicularly loaded on the middle part of the first interconnection slotline at the other end, and grounded on the upper side of the first interconnection slotline.

[0028] Preferably, the length of the first interconnection slotline of the 90° phase shift unit is 26 mm, and the length of the second interconnection slotline is 6.8 mm; the width of the first microstrip line of the first microstrip-slotline adapter structure is 0.9 mm, and the width of the first microstrip line of the third microstrip-slotline adapter structure is 1.85 mm; the resistance values of the two resistors are both 10 ohm, and the widths of the plurality of first slotlines are all 0.5 mm.

[0029] Preferably, the fifth phase shift unit is a 180° phase shift unit, and the switch switching microstrip-slotline adapter structure comprises:

[0030] a second microstrip line;

[0031] a third microstrip line, one end of which is connected to one end of the second microstrip line;

[0032] a fifth diode, the anode of which is connected to the other end of the second microstrip line and the cathode of which is connected to the output end of the interconnecting microstrip line;

[0033] a sixth diode, the cathode of which is connected to the other end of the third microstrip line and the anode of which is connected to the output end of the interconnecting microstrip line;

[0034] a third interconnecting slot line, one end of which is connected to the other ends of the second and third microstrip lines;

[0035] a second slot line, one end of which is short-circuited and the other end of which is connected to the third interconnecting slot line;

[0036] a second DC bias resistor, one end of which is connected to the other ends of the second and third microstrip lines;

[0037] a second DC bias voltage, the output end of which is connected to the other end of the second DC bias resistor.

[0038] Preferably, it further comprises:

[0039] an input feed line for inputting a signal;

[0040] a DC blocking capacitor, one end of which is connected to the input feed line and the other end of which is connected to the input end of the nearest interconnecting microstrip line;

[0041] a third slot line, one end of which is short-circuited and the other end of which is connected to the other end of the second slot line;

[0042] a fourth microstrip line, one end of which is open-circuited and the other end of which is vertically loaded on the other end of the third interconnecting slot line;

[0043] an output feed line, the input end of which is connected to the other end of the fourth microstrip line;

[0044] a plurality of high-resistance grounding lines, each of which is vertically connected to the middle of the corresponding interconnecting microstrip line;

[0045] The electric length of the plurality of high-resistance grounding lines, the third slot line and the fourth microstrip line at the center frequency is one quarter of a wavelength.

[0046] Preferably, it further comprises:

[0047] a dielectric substrate, on the front surface of which all the microstrip lines, diodes, capacitors and resistors are fixed;

[0048] a ground metal plate, which is arranged on the back surface of the dielectric substrate and inside which all the slot lines are located;

[0049] The medium substrate has a relative dielectric constant of 3.55, a thickness of 0.508 mm, and a center frequency of 3.5 GHz.

[0050] Compared with the prior art, the present application has the following advantages:

[0051] 11.25° phase shift unit, 22.5° phase shift unit and 45° phase shift unit adopt microstrip-slot line switching structure to realize phase slope control, which realizes the purpose of wideband phase shift, expands the function and application scene of traditional microstrip-slot line switching structure, 90° phase shift unit is designed in combination with two phase slope adjustment modes, and has greater design flexibility compared with traditional design method, and 180° phase shift unit is realized based on microstrip-slot line switching structure, and has the advantages of simple design method and circuit structure and high phase shift precision.

[0052] The digital phase shifter adopts a hybrid microstrip-slot line structure, which is different from the traditional digital phase shifter realized by high-low network, all-pass network and switch filter network, and has a simpler design principle and circuit structure, and does not use inductance, which makes the design method more easily realized at a higher frequency. Since the present application proposes two effective phase slope adjustment structures, the problem of large in-band phase error of the traditional switch line phase shifter is greatly improved, and the digital phase shifter has the advantages of wideband characteristics and high phase shift precision. BRIEF DESCRIPTION OF DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0054] Figure 1 is a wideband five-bit digital phase shifter structure schematic diagram based on a hybrid microstrip-slot line structure of the present application;

[0055] Figure 2 is a wideband five-bit digital phase shifter side view based on a hybrid microstrip-slot line structure of the present application;

[0056] Figure 3 is a three-dimensional full-wave simulation result of insertion loss and return loss of the wideband five-bit digital phase shifter based on a hybrid microstrip-slot line structure of the present application;

[0057] Figure 4 is a three-dimensional full-wave simulation result of phase shift of the wideband five-bit digital phase shifter based on a hybrid microstrip-slot line structure of the present application;

[0058] Figure 5is the three-dimensional full-wave simulation result of the root mean square phase error and the root mean square amplitude error of the wideband five-bit digital phase shifter based on the mixed microstrip-slot line structure of the application. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative work are within the protection scope of the application.

[0060] With reference to Figure 1 and Figure 2 The application provides a wideband five-bit digital phase shifter based on a mixed microstrip-slot line structure, which comprises a first phase shift unit, a second phase shift unit, a third phase shift unit, a fourth phase shift unit and a fifth phase shift unit connected in sequence through interconnected microstrip lines. The first phase shift unit is a 90° phase shift unit 400, the second phase shift unit is an 11.25° phase shift unit 100, the third phase shift unit is a 22.5° phase shift unit 200, the fourth phase shift unit is a 45° phase shift unit 300, and the fifth phase shift unit is a 180° phase shift unit 500.

[0061] The 90° phase shift unit adopts four microstrip-slot line switching structures, two single-pole double-throw switch structures and a short-circuit microstrip, and is used for realizing 90° phase shift. The 11.25° phase shift unit adopts four microstrip-slot line switching structures and two single-pole double-throw switch structures, and is used for realizing 11.25° phase shift. The 22.5° phase shift unit adopts four microstrip-slot line switching structures and two single-pole double-throw switch structures, and is used for realizing 22.5° phase shift. The 45° phase shift unit adopts four microstrip-slot line switching structures and two single-pole double-throw switch structures, and is used for realizing 45° phase shift. The 180° phase shift unit adopts a switch switching microstrip-slot line switching structure, and is used for realizing 180° phase shift. The phase shifter takes 11.25° as a phase shift step value, and can realize 32 phase shift states in the range of 0°-360° in total.

[0062] The four microstrip-slot line switching structures are arranged on the upper and lower sides of the two SPDT switch structures respectively.

[0063] The two microstrip-slot line switching structures on the same side are connected through the interconnecting slot lines. The phase shift amount is adjusted by changing the length of the two interconnecting slot lines.

[0064] The topologies of the four microstrip-slot line switching structures are the same, including a first microstrip line and a first slot line, and one end of the first microstrip line is open, and one end of the first slot line is shorted. The topologies of the two SPDT switch structures are symmetrically arranged on the left and right sides. The first diode is connected between the ground and the other end of the first microstrip line of the first microstrip-slot line switching structure.

[0065] The phase shifter further comprises a 50-ohm input feed line 1, a 50-ohm output feed line 2, a DC blocking capacitor 3, a first interconnecting microstrip line 4, a second interconnecting microstrip line 5, a third interconnecting microstrip line 6, a fourth interconnecting microstrip line 7, a fifth interconnecting microstrip line 8, a first high-resistance grounding line 9, a second high-resistance grounding line 10, a third high-resistance grounding line 11, a fourth high-resistance grounding line 12, a fifth high-resistance grounding line 13, a ninth interconnecting slot line 14, an eighteenth slot line 15, a twentieth microstrip line 16, a dielectric substrate 17, and a grounding metal plate 18.

[0066] In this embodiment, the switch is realized by a PIN diode, and the equivalent resistance is 2 ohm when it is turned on, and the equivalent capacitance is 0.15 pF when it is turned off.

[0067] Example 1

[0068] like Figure 1 As shown, the 11.25° phase shift unit 100 includes a first microstrip line 101, a second microstrip line 102, a third microstrip line 103, a fourth microstrip line 104, a first slot line 105, a second slot line 106, a third slot line 107, a fourth slot line 108, a first diode 109, a second diode 110, a third diode 111, a fourth diode 112, a fifth diode 113, a sixth diode 114, a seventh diode 115, an eighth diode 116, a first DC bias resistor 117, a second DC bias resistor 118, a third DC bias resistor 119, a fourth DC bias resistor 120, a first interconnect slot line 121, a second interconnect slot line 122, and a first DC bias voltage 123. One end of the first microstrip line 101 is open, and the other end is interconnected with the negative terminal of the third diode 111, the positive terminal of the fourth diode 112, and the first end of the second DC bias resistor 118, while being vertically loaded onto the first end of the second interconnect slot line 122. The second microstrip line 102 is open at one end and interconnected at the other end with the negative terminal of the seventh diode 115, the positive terminal of the eighth diode 116, and the first end of the fourth DC bias resistor 120, while being vertically loaded at the second end of the second interconnect slot line 122. The third microstrip line 103 is open at one end and interconnected at the other end with the negative terminal of the first diode 109, the positive terminal of the second diode 110, and the first end of the first DC bias resistor 117, while being vertically loaded at the first end of the first interconnect slot line 121. The fourth microstrip line 104 is open at one end and interconnected at the other end with the negative terminal of the fifth diode 113, the positive terminal of the sixth diode 114, and the first end of the third DC bias resistor 119, while being vertically loaded at the second end of the first interconnect slot line 121. The first slot line 105 is short-circuited at one end and interconnected at the other end with the first end of the second interconnect slot line 122; the second slot line 106 is short-circuited at one end and interconnected at the other end with the second end of the second interconnect slot line 122. One end of the third interconnecting line 107 is short-circuited, and the other end is interconnected with the first end of the first interconnecting line 121. One end of the fourth interconnecting line 108 is short-circuited, and the other end is interconnected with the second end of the first interconnecting line 121.

[0069] The length and width of the first microstrip line 101 and the second microstrip line 102 are 12.3 mm and 1.19 mm, respectively. The length and width of the third microstrip line 103 and the fourth microstrip line 104 are 12.3 mm and 1.4 mm, respectively. The length and width of the first slot line 105, the second slot line 106, the third slot line 107, and the fourth slot line 108 are 15 mm and 0.15 mm, respectively. The lengths of the first interconnect slot line 121 and the second interconnect slot line 122 are 4 mm and 7.8 mm, respectively, and the width of both is 0.15 mm. The DC bias resistors are all 2 kΩ. The DC control voltage is ±20 V.

[0070] The electrical lengths of the first microstrip line 101, the second microstrip line 102, the third microstrip line 103, the fourth microstrip line 104, the first slot line 105, the second slot line 106, the third slot line 107, and the fourth slot line 108 at the center frequency are one-quarter wavelengths. The positive terminal of the first diode 109 is grounded; the negative terminal of the second diode 110 is connected to the second terminal of the second interconnecting microstrip line 5; the positive terminal of the third diode 111 is connected to the second terminal of the second interconnecting microstrip line 5; the negative terminal of the fourth diode 112 is grounded; the positive terminal of the fifth diode 113 is grounded; the negative terminal of the sixth diode 114 is connected to the first terminal of the third interconnecting microstrip line 6; the positive terminal of the seventh diode 115 is connected to the first terminal of the third interconnecting microstrip line 6; and the negative terminal of the eighth diode 116 is grounded. The second terminal of the first DC bias resistor 117 is interconnected with the first DC bias voltage 123; the second terminal of the second DC bias resistor 118 is interconnected with the first DC bias voltage 123; the second terminal of the third DC bias resistor 119 is interconnected with the first DC bias voltage 123; and the second terminal of the fourth DC bias resistor 120 is interconnected with the first DC bias voltage 123.

[0071] like Figure 1 As shown, the 22.5° phase shifting unit 200, the 45° phase shifting unit, and the 11.25° phase shifting unit 100 adopt the same topology. The difference is that the lengths of the third interconnecting slot line 221 and the fifth interconnecting slot line 321 are 10.6 mm and 15.4 mm, respectively, and the widths of the seventh microstrip line 203, the ninth microstrip line 301, and the eleventh microstrip line 303 are 1.65 mm, 0.9 mm, and 1.95 mm, respectively.

[0072] Example 2

[0073] like Figure 1 As shown, the 90° phase shift unit 400 includes a thirteenth microstrip line 401, a fourteenth microstrip line 402, a fifteenth microstrip line 403, a sixteenth microstrip line 404, a seventeenth microstrip line 426, a thirteenth slot line 405, a fourteenth slot line 406, a fifteenth slot line 407, a sixteenth slot line 408, a twenty-fifth diode 409, a twenty-sixth diode 410, a twenty-seventh diode 411, a twenty-eighth diode 412, a twenty-ninth diode 413, a thirtieth diode 414, a thirty-first diode 415, a thirty-second diode 416, a thirteenth DC bias resistor 417, a fourteenth DC bias resistor 418, a fifteenth DC bias resistor 419, a sixteenth DC bias resistor 420, a seventh interconnect slot line 421, an eighth interconnect slot line 422, a fourth DC bias voltage 423, a first resistor 424, and a second resistor 425.

[0074] The negative terminal of the twenty-sixth diode 410 is interconnected with the second end of the first interconnecting microstrip line 4; the positive terminal of the twenty-seventh diode 411 is interconnected with the second end of the first interconnecting microstrip line 4; the negative terminal of the thirtieth diode 414 is interconnected with the first end of the second interconnecting microstrip line 5; the positive terminal of the thirty-first diode 415 is interconnected with the first end of the second interconnecting microstrip line 5; the positive terminal of the twenty-fifth diode 409 is interconnected with the positive terminal of the twenty-ninth diode 413, and together they are interconnected with the second resistor 425, which is grounded at one end; the negative terminals of the twenty-eighth diode 412 and the thirty-second diode 416 are interconnected with the negative terminals of the first resistor 424, which is grounded at one end; the first end of the seventeenth microstrip line 426 is vertically loaded in the middle of the eighth interconnecting slot line 422 and grounded on the upper side of the eighth interconnecting slot line 422; the second end of the seventeenth microstrip line 426 is grounded. The other parts of the 90° phase shifting unit 400 and the 11.25° phase shifting unit 100 adopt the same topology.

[0075] The lengths of the seventh interconnect line 421 and the eighth interconnect line 422 are 6.8 mm and 26 mm, respectively; the widths of the thirteenth microstrip line 401 and the fifteenth microstrip line 403 are 0.9 mm and 1.85 mm, respectively, and the width of the seventeenth microstrip line 426 is 0.85 mm. The resistance of the first resistor 424 and the second resistor 425 is 10 ohms. The widths of the thirteenth slot line 405, the fourteenth slot line 406, the fifteenth slot line 407, and the sixteenth slot line 408 are 0.5 mm.

[0076] Example 3

[0077] like Figure 1 As shown, the 180° phase shifting unit 500 includes an eighteenth microstrip line 501, a nineteenth microstrip line 502, a seventeenth slot line 503, a thirty-third diode 504, a thirty-fourth diode 505, a seventeenth DC bias resistor 506, and a fifth DC bias voltage 507.

[0078] The first terminal of the eighteenth microstrip line 501 is interconnected with the positive terminal of the thirty-third diode 504, and the second terminal is interconnected with the second terminal of the nineteenth microstrip line 502, and is perpendicularly loaded onto the first terminal of the ninth interconnect slot line 14. The first terminal of the nineteenth microstrip line 502 is interconnected with the negative terminal of the thirty-fourth diode 505; one end of the seventeenth slot line 503 is short-circuited, and the other end is interconnected with the first terminal of the ninth interconnect slot line 14. The negative terminal of the thirty-third diode 504 is interconnected with the second terminal of the fifth interconnect microstrip line 8, and the positive terminal of the thirty-fourth diode 505 is interconnected with the second terminal of the fifth interconnect microstrip line 8. The first terminal of the seventeenth DC bias resistor 506 is interconnected with the second terminal of the eighteenth microstrip line 501, and the first terminal of the seventeenth DC bias resistor 506 is interconnected with the second terminal of the nineteenth microstrip line 502. The second terminal of the seventeenth DC bias resistor 506 is interconnected with the fifth DC bias voltage 507.

[0079] The first end of the DC blocking capacitor 3 is interconnected with the 50-ohm input feed line 1, and the second end is interconnected with the first end of the first interconnected microstrip line 4; the first high-resistance grounding line 9 is interconnected with the first end of the first interconnected microstrip line 4; the second high-resistance grounding line 10 is vertically interconnected in the middle of the second interconnected microstrip line 5; the third high-resistance grounding line 11 is vertically interconnected in the middle of the third interconnected microstrip line 6; the fourth high-resistance grounding line 12 is vertically interconnected in the middle of the fourth interconnected microstrip line 7; the fifth high-resistance grounding line 13 is vertically interconnected in the middle of the fourth interconnected microstrip line 7; one end of the eighteenth slot line 15 is short-circuited, and the other end is interconnected with the second end of the ninth interconnected slot line 14; the first end of the twentieth microstrip line 16 is open-circuited, and the second end is vertically loaded on the second end of the ninth interconnected slot line 14; the second end of the twentieth microstrip line 16 is interconnected with the 50-ohm output feed line 2. First high-resistance grounding wire 9, second high-resistance grounding wire 10, third high-resistance grounding wire 11, fourth high-resistance grounding wire 12, fifth high-resistance grounding wire 13, eighteenth slot wire 15, twentieth microstrip line 16, with an electrical length of one-quarter wavelength at the center frequency.

[0080] The aforementioned microstrip line, diode, capacitor, and resistor are fixed on the front side of the dielectric substrate 17, and the groove line is located in the ground metal plate 18 on the back side of the dielectric substrate 17; the relative permittivity of the dielectric substrate 17 is 3.55, the thickness is 0.508 mm, and the center frequency is 3.5 GHz.

[0081] like Figure 3 As shown, the digital phase shifter using this embodiment has a return loss better than 10.5 dB and an insertion loss better than 5.2 dB in the 2.5–4.5 GHz range (57% of the relative bandwidth).

[0082] like Figure 4 and Figure 5 As shown, the digital phase shifter using this embodiment has a root mean square phase error better than 3.8° and a root mean square amplitude error better than 0.28dB.

[0083] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0084] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A broadband five-bit digital phase shifter based on hybrid microstrip-slotline structure, characterized by, The first phase-shifting unit, the second phase-shifting unit, the third phase-shifting unit, the fourth phase-shifting unit and the fifth phase-shifting unit are sequentially connected through an interconnecting microstrip line; The first phase-shifting unit, the second phase-shifting unit, the third phase-shifting unit and the fourth phase-shifting unit each include four microstrip-slot line switching structures and two single-pole double-throw switch structures, the four microstrip-slot line switching structures are respectively arranged on the upper and lower sides of the two single-pole double-throw switch structures, the two microstrip-slot line switching structures on different sides are switched through the single-pole double-throw switch, and the two microstrip-slot line switching structures on the same side are connected through an interconnecting slot line; The first phase-shifting unit further includes a short-circuit microstrip line vertically loaded in the middle of the lower interconnecting slot line; The fifth phase-shifting unit includes a switch switching microstrip-slot line switching structure, and the switch switching microstrip-slot line switching structure includes a microstrip line vertically loaded on a slot line; The lengths of the two interconnecting slot lines on different sides of the first phase-shifting unit, the second phase-shifting unit, the third phase-shifting unit and the fourth phase-shifting unit are different, and the characteristic impedances of the microstrip lines in the microstrip-slot line switching structures on different sides are different; The four microstrip-slot line switching structures include a first microstrip-slot line switching structure, a second microstrip-slot line switching structure, a third microstrip-slot line switching structure and a fourth microstrip-slot line switching structure; The topologies of the four microstrip-slot line switching structures are the same, and include: A first microstrip line, one end of which is open; A first slot line, one end of which is short-circuited; The topologies of the two single-pole double-throw switch structures are symmetrically arranged on the left and right sides, and the single-pole double-throw switch structure on the left side includes: A first diode, the negative electrode of which is grounded, and the positive electrode of which is connected to the other end of the first microstrip line of the first microstrip-slot line switching structure; A second diode, the positive electrode of which is connected to the output end of the interconnecting microstrip line; A third diode, the negative electrode of which is connected to the output end of the interconnecting microstrip line; A fourth diode, the positive electrode of which is grounded, and the negative electrode of which is connected to the other end of the first microstrip line of the third microstrip-slot line switching structure; Two first direct current bias resistors, one end of each of which is connected to the other end of the two first microstrip lines of the first microstrip-slot line switching structure and the third microstrip-slot line switching structure; Two first direct current bias voltages, the outputs of which are interconnected to the other ends of the two first direct current bias resistors; The fifth phase-shifting unit is a 180° phase-shifting unit, and the switch switching microstrip-slot line switching structure includes: A second microstrip line; A third microstrip line, one end of which is interconnected to one end of the second microstrip line, and the other ends of the second microstrip line and the third microstrip line are vertically loaded on one end of the third interconnecting slot line; A fifth diode, the positive electrode of which is interconnected to the other end of the second microstrip line, and the negative electrode of which is connected to the output end of the interconnecting microstrip line; A sixth diode, the negative electrode of which is interconnected to the other end of the third microstrip line, and the positive electrode of which is connected to the output end of the interconnecting microstrip line; A second slot line, one end of which is short-circuited, and the other end of which is interconnected to the third interconnecting slot line; A second direct current bias resistor, one end of which is interconnected to the other ends of the second microstrip line and the third microstrip line; A second direct current bias voltage, the output end of which is interconnected to the other end of the second direct current bias resistor.

2. A wideband five-bit digital phase shifter based on a hybrid microstrip-slotline structure according to claim 1, characterized in that, A first interconnection slot line is arranged between the first microstrip-slot line adapter structure and the second microstrip-slot line adapter structure, and the other ends of the two first slot lines of the first microstrip-slot line adapter structure and the second microstrip-slot line adapter structure are respectively interconnected with the two ends of the first interconnection slot line, and the other ends of the two first microstrip lines are both vertically loaded on the two ends of the first interconnection slot line; A second interconnection slot line is arranged between the second microstrip-slot line adapter structure and the fourth microstrip-slot line adapter structure, and the other ends of the two first slot lines of the third microstrip-slot line adapter structure and the fourth microstrip-slot line adapter structure are respectively interconnected with the two ends of the second interconnection slot line, and the other ends of the two first microstrip lines are both vertically loaded on the two ends of the second interconnection slot line.

3. A wideband five-bit digital phase shifter based on a hybrid microstrip-slotline structure according to claim 1, wherein, The second phase shift unit is a 11.25° phase shift unit, the widths of the first microstrip lines of the first microstrip-slot line adapter structure and the second microstrip-slot line adapter structure are both 1.19 mm, and the width of the first microstrip line of the third microstrip-slot line adapter structure and the fourth microstrip-slot line adapter structure is 1.4 mm; the length and width of the plurality of first slot lines are both 15 mm and 0.15 mm, the length of the second interconnection slot line is 4 mm, the length of the first interconnection slot line is 7.8 mm, and the plurality of first DC bias resistors are all 2 Kohm, and the plurality of first DC bias voltages are all ±20 V; The third phase shift unit is a 22.5° phase shift unit, the length of the second interconnection slot line is 10.6 mm, the width of the first microstrip line of the third microstrip-slot line adapter structure is 1.65 mm, and the sizes of the remaining topological structures are the same as those of the 11.25° phase shift unit; The fourth phase shift unit is a 45° phase shift unit, the length of the second interconnection slot line is 15.4 mm, the width of the first microstrip line of the first microstrip-slot line adapter structure is 0.9 mm, the width of the first microstrip line of the third microstrip-slot line adapter structure is 1.95 mm, and the sizes of the remaining topological structures are the same as those of the 11.25° phase shift unit.

4. The wideband five-bit digital phase shifter based on hybrid microstrip-slotline structure as claimed in claim 1, wherein, The first phase shift unit is a 90° phase shift unit, the negative poles of the two first diodes of the two single-pole double-throw switch structures are both grounded through a first resistor, and the positive poles of the two fourth diodes are both grounded through a second resistor; One end of the short-circuit microstrip line is grounded, and the other end is vertically loaded on the middle part of the first interconnection slot line and grounded on the upper side of the first interconnection slot line.

5. A wideband five-bit digital phase shifter based on a hybrid microstrip-slotline structure according to claim 4, wherein, The length of the first interconnection slot line of the 90° phase shift unit is 26 mm, and the length of the second interconnection slot line is 6.8 mm; the width of the first microstrip line of the first microstrip-slot line adapter structure is 0.9 mm, and the width of the first microstrip line of the third microstrip-slot line adapter structure is 1.85 mm; the resistance values of the two resistors are both 10 ohm, and the widths of the plurality of first slot lines are all 0.5 mm.

6. A wideband five-bit digital phase shifter based on a hybrid microstrip-slotline structure according to claim 1, wherein, Further comprising: an input feed line for inputting a signal; a direct-current blocking capacitor, one end of which is interconnected with the input feed line, and the other end of which is interconnected with the input end of the nearest interconnection microstrip line; a third slot line, one end of which is short-circuited, and the other end of which is interconnected with the other end of the third interconnection slot line; a fourth microstrip line, one end of which is open-circuited, and the other end of which is vertically loaded on the other end of the third interconnection slot line; an output feed line, the input end of which is interconnected with the other end of the fourth microstrip line; A plurality of high resistance ground wires are vertically connected to the middle of the plurality of interconnected microstrip lines, respectively; The electrical length of the plurality of high resistance ground wires, the third slot line and the fourth microstrip line at the center frequency is a quarter wavelength.

7. A wideband five-bit digital phase shifter based on a hybrid microstrip-slotline structure according to claim 6, wherein, Further comprising: A dielectric substrate, all microstrip lines, diodes, capacitors and resistors are fixed on the front surface of the dielectric substrate; A ground metal plate is arranged on the back surface of the dielectric substrate, and all slot lines are located inside the ground metal plate; The relative dielectric constant of the dielectric substrate is 3.55, the thickness is 0.508 mm, and the center frequency is 3.5 GHz.

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