Electrically tunable substrate integrated waveguide equalizer based on MESFET and varactor

Abstract

The invention relates to a microwave and millimeter wave technology, in particular to an electrically tunable substrate integrated waveguide equalizer based on MESFETs and variable capacitance diodes, which comprises an SIW body, two ends of the SIW body are respectively provided with a 50-ohm microstrip line, and the 50-ohm microstrip lines are connected with the SIW body through gradual transition lines; a rectangular area formed by a groove type frame is arranged in the center of an SIW body, a plurality of electronic elements are arranged on the groove type frame of the rectangular area, MESFETs are introduced into the electronic elements, and variable microwave resistance is fitted by utilizing the characteristic that the MESFETs present different impedance characteristics between a drain and a source under different gate voltages. And the impedance value is adjusted by adjusting the direct-current grid voltage on the MESFETs. According to the invention, the balance value is dynamically and uniformly adjusted, and the adjustment range is widened.

Description

Technical Field

[0001] The present invention relates to microwave and millimeter wave technology, in particular to an electrically adjustable substrate integrated waveguide (SIW) equalizer based on MESFET and varactor diode. Background Art

[0002] SIW (substrate integrated waveguide) can realize the transmission characteristics of traditional metal waveguide on dielectric substrate, and has many advantages of rectangular waveguide and microwave planar circuit, specifically, it has the characteristics of low radiation, low insertion loss, high Q value, high power capacity, etc., and it also has the advantages of miniaturization and easy integration, and it is compatible with existing PCB processing technology. Equalizer is one of the basic components in microwave millimeter wave circuits and systems. In engineering applications, it is usually used to compensate the frequency response of the amplitude and improve the overall flatness of the circuit.

[0003] The current reports on electronically adjustable equalizers working in microwave / millimeter wave bands are as follows:

[0004] SCBera has designed an active equalizer based on PIN diodes, which is mainly used to correct the circuit frequency and perform temperature compensation. It controls the change of the equalization curve by controlling the bias current of the PIN diode. In the 3-5GHz frequency band, the maximum attenuation variable range of -2dB to -10dB can be achieved. See SCBera, "Amplitude Tilt Active Equalizer for Frequency and Temperature Compensation," in IEEE Microwave Wireless Component Letter, 2011, 21(7): 344-346. DOI: 10.1109 / LMWC.2011.2152385.

[0005] Lei Han designed a reconfigurable microwave equalizer with different maximum attenuations based on RF MEMS switches. The equalizer is driven by four transverse DC contact RF MEMS switches. In the frequency range of 17-19 GHz, the equalization value curve is a single slope type, and four maximum attenuations of 7.0 dB, 6.6 dB, 5.9 dB and 4.9 dB can be discretely realized. See Han L, "A Reconfigurable Microwave Equalizer With Different Maximum Attenuations Based on RF MEMS Switches," IEEE Sensors Journal, 2015, 16(1): 17-18. DOI: 10.1109 / JSEN.2015.2482999.

[0006] The Chinese patent application with application number CN202410007179.7 discloses a substrate integrated waveguide tuning pit equalizer based on varactor diodes and PIN diodes. A rectangular area is set on the SIW body, and multiple resonant units are set on the two long sides of the rectangular area. The depth and frequency of the pit are controlled by adjusting the forward voltage difference across the PIN diode and the reverse voltage of the varactor diode. See the national invention patent "A substrate integrated waveguide tuning pit equalizer based on varactor diodes and PIN diodes".

[0007] At present, the amount of equalization required by different microwave circuits is difficult to predict in advance, so there is a more important requirement for the developed equalizer, that is, it must be able to dynamically adjust the amount of equalization within a certain frequency range. The above three existing technologies mainly have the following problems: the first equalizer has a low operating frequency (no more than 5GHz); the second equalizer has a small range of adjustable equalization values ​​(the range of the equalization value is only 4.9-7.0dB); the equalization value of the third equalizer is too sensitive to voltage changes, easily affected by external interference, and has high requirements for the accuracy of the control voltage. Therefore, within a predetermined frequency band and under the condition that the equalization value can be dynamically adjusted, designing an electrically adjustable equalizer with a higher operating frequency, a larger range of equalization values, and a lower adjustment sensitivity of the equalization amount is of great significance to the future development of the electrically adjustable equalizer. Summary of the invention

[0008] The purpose of the present invention is to provide an electrically adjustable substrate integrated waveguide equalizer based on MESFET and varactor diode, utilizing the characteristic that "MESFET presents different impedance characteristics between drain and source under different gate voltages" to "fit" the variable microwave resistor, and adjusting the impedance value by adjusting the DC gate voltage on the MESFET, thereby achieving dynamic and uniform adjustment of the equalization value in a larger range; utilizing the characteristic that the capacitance value of the varactor diode changes with the DC voltage, the resonant center frequency of the equalizer is changed by changing the voltage value.

[0009] An electrically adjustable substrate integrated waveguide equalizer based on MESFET and varactor diode comprises: a SIW body, two ends of the SIW body are provided with a section of 50Ω microstrip line, and the 50Ω microstrip line and the SIW body are connected through a gradual transition line;

[0010] The SIW body is provided with a rectangular area, two rows of first metallized through holes, and electronic components; the two rows of first metallized through holes are symmetrically arranged on both sides of the line connecting the centers of the wide sides of the SIW body; the rectangular area is located at the center of the SIW body and between the two rows of first metallized through holes, and its four frames are all groove-shaped frames, and the long frame and the wide frame correspond to the long side and the wide side of the SIW body respectively; the electronic components are arranged on the groove-shaped frame of the rectangular area, including: a plurality of resonant units and a plurality of capacitors C1, the plurality of resonant units are arranged on two opposite groove-shaped frames as the long sides of the rectangular area, and the plurality of capacitors C1 are arranged on two opposite groove-shaped frames as the wide sides of the rectangular area; wherein:

[0011] Each of the multiple resonant units is equivalent to an RLC parallel resonant circuit, which includes a resistor R, an inductor L and a capacitor C; the resistor R includes a first chip capacitor, a second chip capacitor and a MESFET, the first chip capacitor is connected to the gate G of the MESFET through a gold wire, and acts as a bridge; the second chip capacitor is connected to the drain D of the MESFET through a gold wire, and is used to isolate direct current and pass alternating current; the source S of the MESFET is grounded; the inductor L includes two gold wires, a third chip capacitor and a fourth chip capacitor, the third chip capacitor and the fourth chip capacitor are symmetrically arranged on both sides of the groove frame, and the two are connected by two gold wires, and the gold wire behaves as an inductor in the Ku band; the capacitor C is used to adjust the resonant center frequency and is composed of a varactor diode.

[0012] Furthermore, in order to accurately match the SIW body with the 50Ω microstrip line, two second metallized through holes are introduced at both ends of the SIW body, which are located on both sides of the junction between the gradient transition line and the wide side of the SIW body, for a total of four second metallized through holes.

[0013] Furthermore, the SIW body has a long side length of L s ; The length of the grooved border as the long side of the rectangular area is L r, the length of the groove-shaped frame as the wide side is d; the gradient transition line is located in the middle of the two opposite wide sides of the SIW body, and its length is L t , the width of the end connected with the SIW body is W t , the width of the 50Ω microstrip line is W.

[0014] Furthermore, the diameter of the metallized through hole is d vp , the hole center distance between two adjacent first metallized through holes is s vp , the distance between the two rows of first metallized through holes is W p In the long side direction of the SIW body, the center distance between the second metallized through hole and the first metallized through hole adjacent to it is L x , the hole center distance in the wide side direction of SIW body is L y .

[0015] Furthermore, in two adjacent resonant units in the rectangular area: the spacing between the MESFETs is S r The capacitors C1 are arranged at equal intervals on the two opposite groove-shaped frames as the wide sides of the rectangular area, and the spacing between adjacent capacitors C1 is S c .

[0016] Furthermore, the SIW body adopts Rogers 5880 as the dielectric substrate.

[0017] The working principle of the electronically adjustable equalizer of the present invention is: in the SIW body, the electromagnetic wave is TE 10 The two rows of metallized through holes in the SIW body and the metal covered on the front and back sides of the equalizer together constitute the boundary that constrains the propagation of electromagnetic waves; in the implementation of the "electrically adjustable variable" resistor R, a fixed forward DC voltage V is applied to the drain D of the MESFET. ds (V ds The variable DC negative voltage V is applied to the gate G of the MESFET. gs , used to change the AC microwave resistance r between its drain and source ds , in order to realize the function of adjustable depth of resonance pit; in the composition of inductor L, the two bonded gold wires can be equivalent to high-frequency inductor, and together with the two chip capacitors, realize the function of blocking DC and passing AC; in the adjustment of capacitor C, a reverse bias DC voltage V is applied to the varactor diode c , changing its capacitance value to achieve the function of adjustable resonant center frequency.

[0018] Among the components of the equalizer, MESFET acts as a variable resistor R (applying a suitable forward voltage V to the drain D of the MESFET ds , and the gate G applies a variable DC negative voltage V gsUnder the condition of V gs Controlled variable resistor r ds ), two gold wires as inductance L, and varactor diode as capacitance C, together form an RLC parallel resonant circuit. The admittance of the RLC parallel resonant circuit can be derived as: The resonant angular frequency can be derived as follows:

[0019] By changing the voltage V applied to the varactor diode c The capacitance value in the circuit can be changed. When the capacitance value increases, the resonant frequency decreases, S 21 The resonant center frequency of the curve decreases accordingly. By changing the voltage V applied to the MESFET gate gs , change the AC resistance r between drain and source ds , and then the microwave resistance value in the circuit can be changed. When the microwave resistance increases, the total impedance of the circuit resonance increases, that is, the loss of the circuit increases, corresponding to S 21 The depth of the resonant pit of the curve is deepened. From the above description, it can be known that within the predetermined working frequency band, the center frequency and attenuation of the electrically adjustable SIW equalizer of the present invention can realize continuous regulation of dynamic analog voltage.

[0020] The electrically adjustable SIW equalizer of the present invention is suitable for microwave and millimeter wave circuits, and can solve the problem that the insertion loss of the device at different frequencies is different. By controlling the reverse bias voltage V applied to the varactor diode c To adjust the center frequency of the pit, the negative DC voltage V applied to the MESFET gate is controlled gs To adjust the depth of the pit. At a suitable drain voltage V ds Under control, the gate voltage V gs For every 17.72mV change, the pit depth changes by 1dB (see Fig. 9 ), compared with the average change of 5.91mV and 1dB of pit depth in reference 3, the attenuation adjustment sensitivity of the present invention is lower.

[0021] In addition, the current of the MESFET gate is very small and can be approximated to an open circuit state. Therefore, the actual control voltage source is proportionally amplified by a series voltage divider circuit to expand the range of the control voltage and facilitate the regulation of the equilibrium value. Here is an example: if a 9K resistor and a 1K resistor are connected in series and then grounded, the control signal is connected to one end of the 9K resistor, and the gate G of the MESFET is connected between the two resistors. The source S is grounded, and the drain D is connected to the positive DC voltage V ds , at this time the gate voltage V gs =0.1*V cc , V cc is the control voltage, and V gsCompared to the control voltage V cc The range is expanded by 10 times. In this case, the control voltage V cc The average change is 177.2mV (equivalent to the gate voltage V gs The sensitivity of the present invention is reduced by 30 times, which better solves the engineering problem that the equalization value is sensitive to voltage changes and the equalization value is difficult to adjust. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a top view of the structure of the electrically adjustable SIW equalizer;

[0023] Figure 2 It is the components and structural diagram of the electrically adjustable SIW equalizer;

[0024] Figure 3 The figures are the overall physical picture and partial enlarged picture of the electrically adjustable SIW equalizer, wherein (a) is the overall physical picture, and (b) is the partial enlarged picture of the parallel capacitor, MESFET and varactor diode;

[0025] Figure 4 The S obtained by simulation of the electrically adjustable SIW equalizer dynamically adjusting the capacitance value under different microwave resistances 21 With S 11 Result graph, where the resistance in graph (a) is 25Ω, the resistance in graph (b) is 50Ω, and the resistance in graph (c) is 75Ω;

[0026] Figure 5 It is the simulation value of the equalization amount of the electrically adjustable SIW equalizer under different resistance and capacitance conditions;

[0027] Figure 6 The actual V of the electrically adjustable SIW equalizer under different resonant center frequencies and the same insertion loss is c 、V gs , S 21 and S 11 Test results (TRL calibration de-embedding), where the insertion loss in Figure (a) is -10dB, the insertion loss in Figure (b) is -15dB, the insertion loss in Figure (c) is -20dB, the insertion loss in Figure (d) is -25dB, the insertion loss in Figure (e) is -30dB, and the insertion loss in Figure (f) is -35dB;

[0028] Figure 7 is the varactor diode voltage V c When the V of the electronically adjustable SIW equalizer is fixed at each resonant center frequency, c 、V gs , S21 and S 11 Test results (with TRL calibration de-embedded), where the resonant center frequency in Figure (a) is 13 GHz, the resonant center frequency in Figure (b) is 14 GHz, the resonant center frequency in Figure (c) is 15 GHz, the resonant center frequency in Figure (d) is 16 GHz, and the resonant center frequency in Figure (e) is 17 GHz;

[0029] Figure 8 It is an electrically adjustable SIW equalizer. At each resonant center frequency, the gate voltage V is changed. gs The obtained equalization test results (TRL calibration de-embedding);

[0030] Fig. 9 1 is a comparison result diagram of voltage sensitivity between the electrically adjustable SIW equalizer of the present invention and reference 3;

[0031] Fig.10 It is a schematic diagram of using series resistors to divide the voltage and expand the actual control voltage range;

[0032] Reference numerals: 1 is the SIW body, 2 is the gradual transition line, 3 is the first metallized through hole, 4 is the rectangular groove, and 5 is the second metallized through hole. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and embodiments.

[0034] The invention provides an electrically adjustable SIW equalizer based on MESFET and varactor diode, comprising a SIW body, a gradient transition line and a 50Ω microstrip line. The front and back sides of the SIW body are covered with copper foil, and both ends are connected to the 50Ω microstrip line through a gradient transition line. The different impedance characteristics of MESFET under different gate voltages are used to replace the microwave resistor. By adjusting the DC negative voltage V on the MESFET gate, the DC negative voltage V gs To adjust the impedance value, and then realize the dynamic adjustment of the balance value in a larger range; by using the characteristic that the capacitance value of the varactor diode changes with the DC voltage, by changing the reverse bias voltage V c The value changes the resonant center frequency of the equalizer.

[0035] Example 1

[0036] The electrically adjustable substrate integrated waveguide equalizer provided in this embodiment works in the Ku band, and its top view structure is shown in FIG. Figure 1As shown. The SIW body is provided with two rows of first metallized through holes, a rectangular area and a plurality of electronic components. The plurality of first metallized through holes are symmetrically located on both sides of the long side of the SIW body and are arranged in two rows at equal intervals. The rectangular area is located at the center of the SIW body, and the four sides are all groove structures, wherein the wide side and the long side correspond to the wide side and the long side of the SIW body respectively. The length of the long side of the SIW body is L s , the distance between the two rows of first metallized through holes is W p The hole center distance between two adjacent first metallized through holes is s vp The diameter of the metallized through hole is d vp The gradient transition line is located in the middle of the wide side of the SIW body, and its length is L t , the width of the end connected to the SIW body is W t The width of the 50Ω microstrip line is W. In order to accurately match the SIW body with the 50Ω microstrip line, two second metallized through holes are introduced at both ends of the SIW body. The second metallized through holes are located on both sides of the junction of the gradient transition line and the wide side of the SIW body, for a total of four second metallized through holes. In the long side direction of the SIW body, the center distance between the second metallized through hole and the adjacent first metallized through hole is L x In the wide side direction of the SIW body, the hollow distance between the second metallized through hole and the first metallized through hole adjacent to it is L y .

[0037] like Figure 2 As shown, the electronic components are arranged on the groove-shaped frame of the rectangular area, including: a plurality of resonant units and a plurality of capacitors C1 for isolating direct current from alternating current. The plurality of resonant units are arranged on two opposite groove-shaped frames as the long sides of the rectangular area, and the intervals between the resonant units are the same; the capacitance value of each capacitor C1 is 100pF, and a 01005 package is used. The plurality of capacitors C1 are arranged at equal intervals on two opposite groove-shaped frames as the wide sides of the rectangular area, and are used for isolating direct current from alternating current.

[0038] The distance between the MESFETs in two adjacent resonant units is S r . Six 100pF, 01005 package capacitors C1 are set at equal intervals on the two opposite wide sides of the rectangular area, and the spacing between two adjacent capacitors C1 is S c , used to pass microwave signals.

[0039] In this embodiment, there are 12 resonance units, which are arranged at equal intervals on two opposite long sides of the rectangular area, and each long side is provided with 6 resonance units. The circuit structure of each resonance unit is exactly the same, and they are all composed of an inductor L, a resistor R and a capacitor C in parallel, which is equivalent to an RLC parallel resonance circuit in principle.

[0040] The resistor consists of a first chip capacitor, a second chip capacitor and a MESFET. The first chip capacitor is connected to the gate G of the MESFET through a gold wire to act as a bridge. The second chip capacitor is connected to the drain D of the MESFET through a gold wire to block direct current and pass alternating current. The source of the MESFET is grounded. The part between the drain and source of the MESFET is equivalent to an AC resistor r. ds , the value of which is expressed as the depth of the resonance pit. During assembly, the MESFET is first assembled along the groove, and then the first chip capacitor and the second chip capacitor are assembled in sequence. The chip capacitor model of this embodiment is SK00C101M11A6, and the MESFET model is XT2503.

[0041] The inductor L is composed of two gold wires, a third chip capacitor and a fourth chip capacitor. The third and fourth chip capacitors are distributed on both sides of the groove and are used to isolate direct current and pass alternating current. The gold wires are equivalent to inductors at high frequencies and are located above the two chip capacitors, forming a "Π"-shaped structure with the two chip capacitors. When assembling components, the positions of the third and fourth chip capacitors should be accurately determined first, then the capacitors should be assembled, and finally the two gold wires should be bonded to the plates of the third and fourth chip capacitors. The models of the third and fourth chip capacitors are also SK00C101M11A6.

[0042] Capacitor C is used to adjust the resonant center frequency, which is realized by a varactor diode. The varactor diode model is MAVR-000120-14110P, and the two ends of the varactor diode are connected across the two sides of the groove.

[0043] The actual picture of the electrically adjustable SIW equalizer of this embodiment is as follows Figure 3 (a) and Figure 3 (b) as shown.

[0044] In this embodiment, the electrically adjustable SIW equalizer is implemented using a Rogers 5880 dielectric substrate with a thickness of 0.254mm, a dielectric constant of 2.2, and a tangent loss of 0.0009. The copper thickness is 18um, and the metal layers on both sides are gold-plated, with a final thickness of 40um. After simulation and optimization using the electromagnetic simulation software Ansoft HFSS, the optimal parameter size is obtained, as shown in Table 1:

[0045] Table 1 Physical dimensions of the optimized electronically adjustable equalizer

[0046]

[0047] In the simulation software Ansoft HFSS, the capacitance value of the varactor diode is set as a variable, and its value range is 0.25pF-0.45pF. The simulation analysis is performed with a step capacitance value of 0.05pF. Five groups of data, 0.25, 0.30, 0.35, 0.40, and 0.45, are selected to plot the corresponding S21 and S 11 When the capacitance value of the varactor diode and the resistance value of the MESFET change, the corresponding S 21 and S 11 The change curve of Figure 4 (a) to Figure 4 (c), and Figure 5 As shown in the figure, it can be seen that the pit depth and resonant center frequency of the equalizer can be adjusted within the frequency band; the size of the resistance value controls the depth of the pit, and the size of the capacitance value controls the resonant center frequency.

[0048] Based on the above theory and method, the actual circuit is processed. In the actual test, TRL calibration is first performed to embed the circuit, and then a reverse bias DC variable voltage V is applied to the varactor diode. c , V c Adjustable from 0V to 18V, a fixed voltage V is applied to the drain of the MESFET ds =0.65V(V ds Working in the variable resistance region of MESFET), finally a variable DC negative voltage V is applied to the gate of MESFET gs , V gs Dynamically adjustable within the range of -0.4V to -1.2V, the test data is analyzed and processed as follows.

[0049] First, by changing the voltage V c and V gs Find out the value of V at different frequencies / same insertion loss (-10dB, -15dB, -20dB, -25dB, -30dB and -35dB). c 、V gs , S 21 and S 11 The test results are as follows: Figure 6 (a) to Figure 6 As shown in (f), it can be seen that the center frequency and pit depth of the equalizer are dynamically adjustable within a predetermined frequency band.

[0050] Next, find out the V at each center resonant frequency. c 、V gs , S 21 and S 11 The test results are as follows Figure 7 As shown, the diode reverse bias voltage V c Fixed, only V changes gs We plot the test data of the electronically adjustable equalizer at each center frequency into Table 2. Figure 7 From Table 2, it can be seen that when the resonant frequency of the equalizer remains unchanged, V gsChanges within a certain range will cause changes in the equalization value. To better understand the law of change, we plot the equalization value at each center frequency as a curve, such as Figure 8 As shown: At different frequencies, as the gate voltage V gs The reduction (V gs The absolute value increases), and the equalization amount of the equalizer shows an overall increasing trend.

[0051] Table 2 Test data of the electronically adjustable equalizer at each center frequency

[0052]

[0053] Finally, the reverse bias DC voltage V of the fixed varactor diode is c =9.3V, the center frequency is 15GHz, and the gate voltage V of the MESFET is adjusted every 10mV gs , and tested. The comparative example is the SIW electrically adjustable equalizer based on the varactor diode and the PIN diode described in the background technology. The test results of the SIW electrically adjustable equalizer of the comparative example are compared with the electrically adjustable equalizer of this embodiment, and the comparison results are plotted as Table 3, and the comparison images are plotted as Fig. 9 . It can be seen that when the voltage of the former changes by about 150mV, the maximum loss value of the equalizer reaches -35dB, and the change is too sensitive; when the voltage of this embodiment changes by about 450mV, the maximum loss value reaches -35dB, and the voltage change is about 3 times that of the former, making it easier to adjust the equalizer. In addition, the PIN diode in the comparative example is a current-controlled component and is easily affected by external factors, while the MESFET in this embodiment is a voltage-controlled component and is less affected by the outside world, making it easier to implement in the circuit and more advantageous in practical applications.

[0054] In addition, the current of the MESFET gate is very small, which can be close to the open circuit state. The actual control voltage range can be expanded by connecting a series voltage divider circuit, which is convenient for adjusting the equilibrium value. The schematic diagram is shown in Fig.10 shown. Fig.10 The actual control voltage V cc The voltage is negative DC, resistors R1 and R2 are connected in series, the gate G of the MESFET is connected between the two resistors, the source S is grounded, and the drain D is connected to the positive DC voltage V ds , gate voltage V gs =R2 / (R1+R2)*V cc If R1 = 9KΩ, R2 = 1KΩ, then the gate voltage V gs =0.1*V cc, which is equivalent to expanding the range of the control voltage by 10 times. In Table 3, the voltage variation of the embodiment is linearly expanded from 443mV to 4430mV, which can further reduce the sensitivity of the control voltage and facilitate fine adjustment of the equilibrium value. In reference 3, since the PIN diode has current passing through it, if a resistor is used to divide the voltage, the expanded control voltage and the loading voltage of the PIN diode are nonlinear, the adjustment circuit will be more complicated, and it is impossible to achieve a significant expansion of the control voltage. The impact of external interference on the circuit is greater than that of MESFET.

[0055] Table 3 Comparison of voltage sensitivity between the embodiment and the comparative example

[0056]

[0057] Therefore, in comparison, due to the small control voltage range of PIN diodes (only 150mV), it is difficult to fine-tune the balance value in engineering. Introducing MESFET to replace PIN diodes and realize electrically adjustable microwave resistance can better solve the engineering problem that the balance value is sensitive to voltage changes and difficult to accurately adjust the balance value.

[0058] From the simulation and actual test results, it can be seen that the equalizer adjusts the reverse bias voltage V c and the gate voltage of the MESFET V gs It can realize dynamic electrical adjustment of the equalizer center frequency and equalization value. It has the advantages of higher operating frequency, larger equalization value range and lower adjustment sensitivity of the equalization value. It can effectively solve the problem of amplitude fluctuation of the gain curve and can adjust the circuit response in real time to make the circuit output flatter.

[0059] In summary, the electrically adjustable substrate integrated waveguide equalizer based on MESFET and varactor diode provided in this embodiment overcomes the problems of the PIN diode itself, such as the inability to linearly amplify and the narrow adjustable range, after introducing MESFET into the electronic component, and effectively improves the control range of the equalizer equalization value, which is beneficial to practical engineering applications.

Claims

1. An electrically adjustable substrate integrated waveguide equalizer based on MESFET and varactor diode, comprising: SIW body, both ends of the SIW body are provided with a 50Ω microstrip line, and the 50Ω microstrip line and the SIW body are connected by a gradual transition line, characterized in that: The SIW body is provided with a rectangular area, two rows of first metallized through holes, and electronic components; the two rows of first metallized through holes are symmetrically arranged on both sides of the line connecting the centers of the wide sides of the SIW body; the rectangular area is located at the center of the SIW body and between the two rows of first metallized through holes, and its four frames are all groove-shaped frames, and the long frame and the wide frame correspond to the long side and the wide side of the SIW body respectively; the electronic components are arranged on the groove-shaped frame of the rectangular area, including: a plurality of resonant units and a plurality of capacitors C1, the plurality of resonant units are arranged on two opposite groove-shaped frames as the long sides of the rectangular area, and the plurality of capacitors C1 are arranged on two opposite groove-shaped frames as the wide sides of the rectangular area; wherein: Each of the multiple resonant units is equivalent to an RLC parallel resonant circuit, which includes a resistor R, an inductor L and a capacitor C; the resistor includes a first chip capacitor, a second chip capacitor and a MESFET, the first chip capacitor is connected to the gate G of the MESFET through a gold wire; the second chip capacitor is connected to the drain D of the MESFET through a gold wire; the source of the MESFET is grounded; the inductor L includes two gold wires, a third chip capacitor and a fourth chip capacitor, the third chip capacitor and the fourth chip capacitor are symmetrically arranged on both sides of the groove frame, and the two are connected by two gold wires; the capacitor C is used to adjust the resonant center frequency and is composed of a varactor diode.

2. The electrically adjustable substrate integrated waveguide equalizer based on MESFET and varactor diode according to claim 1, characterized in that: Two second metallized through holes are introduced at each end of the SIW body, and are located on both sides of the junction between the gradual transition line and the wide side of the SIW body, for a total of four second metallized through holes.

3. The electrically adjustable substrate integrated waveguide equalizer based on MESFET and varactor diode according to claim 1, characterized in that: The length of the groove-shaped frame of the long side of the rectangular area is L r , the grooved frame as the wide side is d long, and L r >d.

4. The electrically adjustable substrate integrated waveguide equalizer based on MESFET and varactor diode according to claim 1, characterized in that: In two adjacent resonant units in the rectangular area, the spacing between adjacent MESFETs is S r The capacitors C1 are evenly spaced on the two opposite groove-shaped frames as the wide sides of the rectangular area, and the average spacing between adjacent capacitors C1 is S c .

5. An electrically adjustable substrate integrated waveguide equalizer based on MESFET and varactor diode according to any one of claims 1 to 4, characterized in that: The SIW body adopts Rogers5880 dielectric substrate.

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