Microwave common-time double-frequency miniaturized radiator

Abstract

The invention provides a microwave common-time double-frequency miniaturized radiator. According to the miniaturized radiator, two transistors are adopted to respectively construct negative resistance circuits to compensate resonator energy loss of a microwave common-time dual-frequency oscillator, and then output signals of SIW resonators are radiated and output through metal patches coupled through cross slot gaps. Comprising a high-frequency-band active negative resistance circuit, a high-frequency-band input blocking capacitor C1, a low-frequency-band active negative resistance circuit, a low-frequency-band input blocking capacitor C2, a high-frequency-band input matching circuit, a low-frequency-band input matching circuit and an SIW dual-mode dual-frequency radiation type resonator. According to the invention, the dual-mode resonator gap coupling metal patches are adopted to realize the function of common-time dual-frequency oscillation signal radiation output, and the oscillation signal obtained by radiation has the advantages of high output power, high isolation and low phase noise.

Description

Technical Field

[0001] This invention belongs to the field of microwave technology and relates to a microwave radiator, and more particularly to a miniaturized microwave simultaneous dual-frequency radiator. Background Technology

[0002] With the continuous development of wireless communication technology, especially in fields such as multi-band communication, radar, and satellite communication, more and more systems are beginning to require simultaneous transmission on multiple frequency bands, leading to an increasing demand for high-performance, dual-band microwave radiators. Traditional microwave radiators are generally designed to operate at a single frequency. To meet the needs of communication systems that require operation at different frequencies, dual-band radiators, especially simultaneous dual-band radiators, have gradually become an indispensable and important component in wireless communication systems.

[0003] However, most dual-band microwave radiators currently face a series of challenges in achieving dual-band functionality. Traditional dual-band radiator designs typically require complex structures, such as multiple resonant cavities operating in different frequency bands, resulting in a large radiator area that is difficult to meet the miniaturization requirements of modern communication systems. Secondly, existing dual-band radiators often suffer from poor isolation between different frequency bands and mutual coupling of resonant modes.

[0004] Therefore, how to design a miniaturized, high-performance simultaneous dual-frequency radiator is an urgent problem to be solved in the field of microwave technology. In light of the above background, this paper proposes to provide a miniaturized, high-performance, low-phase-noise microwave simultaneous dual-frequency radiator with good frequency isolation characteristics. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a miniaturized microwave synchronous dual-frequency radiator. Specifically, it is a miniaturized microwave synchronous dual-frequency radiator based on a substrate integrated waveguide (SIW) dual-mode dual-frequency radiating resonator combined with a microwave synchronous dual-frequency oscillation circuit. More specifically, it employs two transistors to construct negative resistance circuits to compensate for the energy loss of the SIW resonator, and radiates the resonant signal of the SIW resonator through a cross-slot-coupled metal patch.

[0006] The technical solution of this invention is as follows:

[0007] A microwave simultaneous dual-frequency miniaturized radiator includes: a high-frequency active negative resistance circuit, a high-frequency input DC blocking capacitor C1, a low-frequency active negative resistance circuit, a low-frequency input DC blocking capacitor C2, a high-frequency input matching circuit, a low-frequency input matching circuit, and a SIW dual-mode dual-frequency radiating resonator; the input terminal of the high-frequency active negative resistance circuit is connected to the collector voltage V. dd and base voltage V gThe output terminal is connected to one end of the high-frequency input DC blocking capacitor C1; the other end of the high-frequency input DC blocking capacitor C1 is connected to the input terminal of the high-frequency input matching circuit; the input terminal of the low-frequency active negative resistance circuit is connected to the collector voltage V. dd and base voltage V g The output terminal is connected to one end of the low-frequency input DC blocking capacitor C2; the other end of the low-frequency input DC blocking capacitor C2 is connected to the input terminal of the low-frequency input matching circuit; the output terminals of the high-frequency input matching circuit and the low-frequency input matching circuit are respectively connected to the two input terminals of the SIW dual-mode dual-frequency radiating resonator.

[0008] The SIW dual-mode dual-frequency radiating resonator comprises, from top to bottom, a top metal layer, a first dielectric substrate, a metal ground plane, a second dielectric substrate, and a bottom metal layer. The first dielectric substrate has multiple periodically distributed first metal vias, which, except at the power supply points, form a closed structure, and both ends of the first metal vias are connected to the top metal layer and the metal ground plane, respectively. The second dielectric substrate has multiple periodically distributed second metal vias, which form a closed structure, and the second metal vias correspond to the first metal vias, with both ends of the first metal vias connected to the metal ground plane and the bottom metal layer, respectively. The top metal layer, the first dielectric substrate, the metal ground plane, and the first metal vias constitute the SIW resonator, while the second dielectric substrate, the bottom metal layer, and the second metal vias constitute the radiator.

[0009] Preferably, the top metal layer includes a rectangular metal patch and two microstrip lines forming an equal-amplitude, in-phase T-type power divider; the two T-type power dividers are respectively connected to two adjacent sides of the rectangular metal patch.

[0010] Preferably, the two branch arms of the T-type power divider are connected to rectangular metal patches, and the converging arm serves as a signal input port.

[0011] Preferably, the length and width of the rectangular metal patch are both smaller than those of the first dielectric substrate.

[0012] Preferably, the first metal through-hole is provided along the edge of the rectangular metal patch.

[0013] Preferably, the metal floor has a cross-shaped slit at its center, which falls within the resonant cavity and does not contact the first metal through hole.

[0014] Preferably, the length and width dimensions of the metal floor are equal to those of the first dielectric substrate.

[0015] Preferably, a rectangular notch is formed at the center of the bottom metal layer, and the rectangular notch falls within the resonant cavity; a radiating patch is disposed within the rectangular notch and does not contact the bottom metal layer.

[0016] More preferably, the center of the projection of the cross-shaped slit onto the bottom metal layer coincides with the center of the radiating patch.

[0017] Preferably, two transistors are used to construct a high-frequency active negative resistance circuit and a low-frequency active negative resistance circuit respectively to compensate for the energy loss of the SIW resonator. The oscillation signal of the SIW resonator is radiated out through the cross-slot gap coupling of the bottom metal layer. The SIW resonator is based on a dual-mode design and can simultaneously excite the TE in a single resonant cavity. 201 and TE 102 Two modes enable dual-frequency radiation characteristics and excellent polarization isolation performance. SIW technology has advantages such as low insertion loss and high Q value, making it suitable for use as a radiator with even lower insertion loss and higher Q value, resulting in an oscillating signal with high output amplitude and excellent phase noise performance.

[0018] The present invention has the following advantages and beneficial effects:

[0019] 1) This invention uses a dual-mode characteristic design of a SIW resonator to create a microwave synchronous dual-frequency radiator, by separating the TE in the resonator. 201 TE 102 The two modes generate different resonant frequencies, and radiate through mutually perpendicular gaps, achieving dual differentiation of frequency and polarization, thus realizing an integrated dual-frequency, dual-polarization design. Combined with a negative-resistance active circuit, two oscillation signals of different frequencies are generated simultaneously, achieving the advantages of high amplitude and good phase noise in the simultaneous dual-frequency oscillation signal output.

[0020] 2) This invention uses an equal-amplitude, in-phase T-type power divider as the feed for the SIW dual-mode dual-frequency radiating resonator, combined with the two modes TE of the resonant cavity. 201 TE 102 The electric field characteristics enable high isolation between the two output signals.

[0021] 3) This invention uses a single-cavity TE 201 TE 102 The two modes generate different resonant frequencies and output them through slot-coupled metal patches. The structure is simple and compact, avoiding complex structures such as multi-cavity resonators. It achieves miniaturization better while maintaining high output power, high isolation, and low phase noise.

[0022] 4) The two modes of radiated electric fields generated by this invention are respectively in the horizontal polarization direction and the vertical polarization direction, which are orthogonal to each other and have natural polarization isolation. Therefore, the polarization isolation of this invention is high, which can effectively reduce cross-polarization interference and improve the signal quality at the receiving end. Attached Figure Description

[0023] Figure 1 Circuit schematic diagram of a microwave synchronous dual-frequency miniaturized radiator design example;

[0024] Figure 2 A structural diagram of a design example for a SIW dual-mode dual-frequency radiating resonator;

[0025] Figure 3 Dimensions for a design example of a SIW dual-mode dual-frequency radiating resonator, where (a) is the top metal layer and (b) is the metal ground plane;

[0026] Figure 4 The diagram shows the electric field distribution of different modes in a rectangular resonant cavity, where (a) represents the electric field distribution of the TE mode. 201 Mode (b) is TE 102 model;

[0027] Figure 5 The curve shows the change of the dual-mode frequency ratio (f1 / f2) of a rectangular cavity with the cavity width-to-length ratio (W1 / L1).

[0028] Figure 6 The effect of the cross-shaped gap size on the S-parameters is shown, where (a) is the length L. c1 The relationship with |S(2,2)|, (b) is the width W c1 The relationship with |S(2,2)|;

[0029] Figure 7 Simulation results for a design example of a SIW dual-mode dual-frequency radiating resonator;

[0030] Figure 8 The far-field radiation pattern of a SIW dual-mode dual-frequency radiating resonator is shown in the design example, where (a) is the radiation pattern of a SIW dual-mode dual-frequency radiating resonator operating at TE. 201 The low-frequency signal in the mode is excited through a slit along the y-axis, (b) is generated by the TE mode. 102 The high-frequency signal in the mode is excited through a slit along the x-axis;

[0031] Figure 9 Gain results for a design example of a SIW dual-mode dual-frequency radiating resonator;

[0032] Figure 10 Example polarization component patterns for SIW dual-mode dual-frequency radiating resonator design, where (a) is 5.70 GHz and (b) is 6.45 GHz;

[0033] Figure 11 The simulation results are shown in the example of receiving antenna design, where (a) represents the vertical polarization direction and (b) represents the horizontal polarization direction.

[0034] Figure 12 This is a spectrum diagram of the received oscillation signal.

[0035] Figure 13 The diagram shows the phase noise of the oscillation signal, where (a) is 5.74 GHz and (b) is 6.50 GHz.

[0036] The diagram is labeled as follows: 1. High-frequency active negative resistance circuit; 2. Low-frequency active negative resistance circuit; 3. High-frequency input matching circuit; 4. Low-frequency input matching circuit; 5. SIW dual-mode dual-frequency radiating resonator; 6. Top metal layer; 6. Rectangular metal patch; 6. T-type power divider; 6. First dielectric substrate; 7. Metal ground plane; 8. Cross-shaped slot; 81. Second dielectric substrate; 9. Bottom metal layer; 10. Rectangular notch; 101. Radiating patch; 102. Detailed Implementation

[0037] The invention will be further illustrated below with reference to the accompanying drawings and examples.

[0038] like Figure 1 As shown, this embodiment provides a microwave simultaneous dual-frequency miniaturized radiator operating at 5.70 GHz and 6.45 GHz, including: a high-frequency active negative resistance circuit 1, a high-frequency input DC blocking capacitor C1, a low-frequency active negative resistance circuit 2, a low-frequency input DC blocking capacitor C2, a high-frequency input matching circuit 3, a low-frequency input matching circuit 4, and a SIW dual-mode dual-frequency radiating resonator 5; the input terminal of the high-frequency active negative resistance circuit 1 is connected to the collector voltage V. dd and base voltage V g The output terminal is connected to one end of the high-frequency input DC blocking capacitor C1; the other end of the high-frequency input DC blocking capacitor C1 is connected to the input terminal of the high-frequency input matching circuit 3; the input terminal of the low-frequency active negative resistance circuit 2 is connected to the collector voltage V. dd and base voltage V g The output terminal is connected to one end of the low-frequency input DC blocking capacitor C2; the other end of the low-frequency input DC blocking capacitor C2 is connected to the input terminal of the low-frequency input matching circuit 4; the output terminals of the high-frequency input matching circuit 3 and the low-frequency input matching circuit 4 are respectively connected to the two input terminals of the SIW dual-mode dual-frequency radiating resonator 5.

[0039] In some embodiments, such as Figure 2As shown, the SIW dual-mode dual-frequency radiating resonator 5 comprises, from top to bottom, a top metal layer 6, a first dielectric substrate 7, a metal ground plane 8, a second dielectric substrate 9, and a bottom metal layer 10. The first dielectric substrate 7 has multiple periodically distributed first metal vias, which, except at the power feeding points, form a closed structure (e.g., a rectangle). The two ends of each first metal via connect to the top metal layer 6 and the metal ground plane 8, respectively. The second dielectric substrate 9 has multiple periodically distributed second metal vias, which form a closed structure (e.g., a rectangle). The second metal vias correspond to the first metal vias, and the two ends of each first metal via connect to the metal ground plane 8 and the bottom metal layer 10, respectively. The top metal layer 6, the first dielectric substrate 7, the metal ground plane 8, and the first metal vias constitute the SIW resonator, while the second dielectric substrate 9, the bottom metal layer 10, and the second metal vias constitute the radiator. The SIW resonator and the radiator, together forming a five-layer structure, constitute the SIW dual-mode dual-frequency radiating resonator.

[0040] Specifically, the top metal layer 6 includes a rectangular metal patch 61 and two microstrip lines forming an equal-amplitude, in-phase T-shaped power divider 62; the two T-shaped power dividers 62 are respectively connected to two adjacent sides of the rectangular metal patch 61. For example, the two branch arms of the T-shaped power divider 62 are connected to the rectangular metal patch 61, and the converging arm serves as a signal input port.

[0041] Specifically, the length and width of the rectangular metal patch 61 are both smaller than those of the first dielectric substrate 7.

[0042] Specifically, the first metal through-hole is provided along the edge of the rectangular metal patch 61.

[0043] In some embodiments, the metal floor 8 has a cross-shaped slit 81 at its center, which falls within the resonant cavity and does not contact the first metal through hole.

[0044] Specifically, the length and width of the metal floor 8 are equal to those of the first dielectric substrate 7.

[0045] In some embodiments, a rectangular notch 101 is formed in the center of the bottom metal layer 10, and the rectangular notch 101 falls within the resonant cavity; a radiating patch 102 is disposed within the rectangular notch 101 and does not contact the bottom metal layer 10.

[0046] Specifically, the projection center of the cross-shaped slit 81 onto the bottom metal layer 10 coincides with the center of the radiating patch 102.

[0047] The microwave synchronous dual-frequency miniaturized radiator provided in this embodiment is a SIW dual-mode dual-frequency radiating resonator. This resonator is a 2-port network, with both ports being input ports. The bottom metal layer 10 radiates electromagnetic signals in two frequency bands. The main body is a rectangular resonant cavity with a length of L1 and a width of W1, as shown below. Figure 3 As shown in (a), port 1 is fed inward by a T-type power divider 62 composed of microstrip lines with equal amplitude and in phase, and port 2 is fed in the same way. Adjusting the slot length L... S1 L S2 Groove width W S1 W S2 The feed strength can be changed; changing the length L1 and width W1 of the rectangular cavity can change the TE in the rectangular cavity. 201 TE 102 The resonant frequency of the mode; changing the distance W from the feed line to the edge of the rectangular cavity. T With W T2 The feed position can be symmetrically controlled to adjust the isolation of the SIW resonator, thereby producing a resonator with high isolation. This is based on the two operating modes of the rectangular resonator, TE. 201 and TE 102 The resonant frequency is determined by adjusting the microstrip line lengths L2, L3, L4, and L5 of the T-type power divider to meet the requirements of the T-type power divider at different frequencies, which helps to achieve high isolation. The electromagnetic signal radiating unit is composed of a cross-shaped slot coupling dielectric substrate at the bottom ground plane of the resonator, with a metal patch attached to the bottom of the dielectric substrate. Adjusting the length and width of the cross-shaped slot in the intermediate metal layer can affect the coupling between the resonator structure and the radiating unit, where the slot length L along the y-axis (i.e., the width direction of the resonator) is... c1 and gap width W c1 Control TE 201 The output of the mode, the gap length L along the x-axis (i.e., the resonator length direction) c2 and gap width W c2 Control TE 102 Output of the mode. Adjust the length and width of the bottom metal layer 10 of the second dielectric substrate to meet the required signal output of the two frequency bands.

[0048] The rectangular resonator operates at TE 201 and TE 102 Two modes, electric field distribution diagrams for both modes are shown below. Figure 4 (a)- Figure 4 In figure (b), it can be seen that the rectangular resonator simultaneously generates two resonant frequencies (corresponding to TE). 102 The mode is f1, corresponding to TE. 201 The mode is f2). During the design, the resonant cavity is designed as a rectangular structure with different lengths L1 and W1, so that its TE... 102 and TE201 The mode resonant frequencies are separated, operating at high and low frequencies respectively, such as Figure 5 As shown: When the width-to-length ratio (W1 / L1) is 1, its TE 201 and TE 102 When the modes have the same resonant frequency, f1 / f2 = 1. As the aspect ratio changes, the resonant frequencies of the two modes gradually diverge, and f1 / f2 increases. The maximum aspect ratio is 1.5, corresponding to a dual-frequency ratio f1 / f2 of 1.276. Beyond this aspect ratio, the TE... 103 The resonant frequency of the mode is less than TE. 102 Pattern, thereby stimulating TE 102 TE mode 103 The mode is also easily excited, which is not conducive to designing a simultaneous dual-frequency radiator with high spectral purity and good isolation. Therefore, the maximum aspect ratio should be much less than 1.5 to prevent TE. 102 Pattern and TE 103 The resonant frequencies of the modes are too close.

[0049] Based on the rectangular resonant cavity operating in dual mode and separating the dual-mode resonant frequencies f1 and f2 by adjusting the width-to-length ratio, and according to the electric field distribution characteristics, a microstrip line-based equal-amplitude in-phase T-type power divider is used as the feed to excite the two modes of the rectangular resonant cavity, and high isolation is obtained by combining phase characteristics. Changing the width-to-length ratio of the rectangular resonant cavity allows the two operating modes of the resonant unit to be separated, resonating at different frequencies f1 and f2; a suitable equal-amplitude in-phase T-type power divider is designed according to the resonant frequency to reduce signal insertion loss; changing W... T W T2 Adjusting the values ​​of the feed distance to the wide and long sides, and adjusting the isolation between ports, allows for the creation of a dual-frequency resonator based on SIW technology. This SIW high-isolation resonator serves as the core of the dual-frequency radiator, contributing to the generation of high-quality oscillating radiation signals.

[0050] A cross-shaped slot is cut into the bottom floor of a rectangular resonant cavity to couple a dielectric substrate for signal transmission, and a metal patch is attached for signal radiation, forming the radiating element of a SIW dual-mode dual-frequency radiating resonator. In the slot coupling structure, the length and width of the slot have a significant impact on the energy coupling efficiency, resonance characteristics, and overall radiation performance. When the slot is fed, the electric field difference at both ends of the slot will induce a strong local electric field in the slot region. This electric field propagates along the edge of the slot and is reflected, forming a standing wave mode. Under specific geometric dimensions and boundary conditions, the slot can induce a standing wave electric field and store electromagnetic energy, exhibiting frequency selectivity and energy amplification characteristics analogous to traditional resonators. The size of the slot affects the coupling between the rectangular resonant cavity and the radiating element; moreover, the longer the slot, the lower the frequency of the radiated signal. Adjusting the size of the patch to enable simultaneous radiation of signals in both high and low frequency bands requires special attention, as the size of the slot and the patch are interrelated. When adjusting the size of the slot to change the radiation frequency, the size of the patch must be adjusted simultaneously. By combining the rectangular resonant cavity structure with the radiating unit, the design of the SIW dual-mode dual-frequency radiating resonator is completed.

[0051] In some embodiments, the high-frequency active negative resistance circuit 1 includes a first common-emitter transistor Q1, a first base bias resistor R1, a first base sector microstrip bias circuit, a first base feedback line TL5, a second base feedback line TL6, a first collector sector microstrip bias circuit, and a first emitter feedback line TL7.

[0052] The first base sector microstrip bias circuit includes a first microstrip line TL1, a second microstrip line TL2, and a first sector microstrip MRSTUB1; the first collector sector microstrip bias circuit includes a third microstrip line TL3, a fourth microstrip line TL4, and a second sector microstrip MRSTUB2.

[0053] One end of the first microstrip line TL1 is connected to the base voltage V. g One end is connected to one end of the second microstrip line TL2 and the tip of the first sector microstrip MRSTUB1; one end of the first base bias resistor R1 is connected to the other end of the second microstrip line TL2, and the other end is connected to one end of the first base feedback line TL5 and one end of the second base feedback line TL6; the other end of the first base feedback line TL5 is left floating; the base of the first common-emitter transistor Q1 is connected to the other end of the second base feedback line TL6, and the collector is connected to one end of the fourth microstrip line TL4 as the output terminal of the high-frequency active negative resistance circuit 1; the emitter is connected to one end of the first emitter feedback line TL7; the other end of the first emitter feedback line TL7 is grounded; the other end of the fourth microstrip line TL4 is connected to one end of the third microstrip line TL3 and the tip of the second sector microstrip MRSTUB2; the other end of the third microstrip line TL3 is connected to the collector voltage V. dd .

[0054] The first base feedback line TL5, the second base feedback line TL6, and the first emitter feedback line TL7 provide positive feedback for transistor Q1. Adjusting their lengths allows a negative resistance state to be observed at the collector. The first base sector-shaped microstrip bias circuit and the first collector sector-shaped microstrip bias circuit isolate DC signals from RF signals and provide a stable DC bias voltage. The base voltage V... g Collector voltage V dd Provides the DC condition for transistor Q1 to conduct.

[0055] In some embodiments, the low-frequency active negative resistance circuit 2 includes a second common-emitter transistor Q2, a second base bias resistor R2, a second base sector microstrip bias circuit, a third base feedback line TL15, a fourth base feedback line TL16, a second collector sector microstrip bias circuit, and a second emitter feedback line TL17. The second base sector microstrip bias circuit includes a fifth microstrip line TL11, a sixth microstrip line TL12, and a third sector microstrip MRSTUB3; the second collector sector microstrip bias circuit includes a seventh microstrip line TL13, an eighth microstrip line TL14, and a fourth sector microstrip MRSTUB4.

[0056] One end of the fifth microstrip line TL11 is connected to the base voltage V. g One end is connected to one end of the sixth microstrip line TL12 and the tip of the third sector microstrip MRSTUB3; one end of the second base bias resistor R2 is connected to the other end of the sixth microstrip line TL12, and the other end is connected to one end of the third base feedback line TL15 and one end of the fourth base feedback line TL16; the other end of the third base feedback line TL15 is left floating; the base of the second common-emitter transistor Q2 is connected to the other end of the fourth base feedback line TL16, and the collector is connected to one end of the eighth microstrip line TL14 as the output terminal of the low-frequency active negative resistance circuit 2; the emitter is connected to one end of the second emitter feedback line TL17; the other end of the second emitter feedback line TL17 is grounded; the other end of the eighth microstrip line TL14 is connected to one end of the seventh microstrip line TL13 and the tip of the fourth sector microstrip MRSTUB4; the other end of the seventh microstrip line TL13 is connected to the collector voltage V. dd .

[0057] The third base feedback line TL15, the fourth base feedback line TL16, and the second emitter feedback line TL17 provide positive feedback for transistor Q2. Adjusting their lengths allows a negative resistance state to be observed at the collector. The second base sector-shaped microstrip bias circuit and the second collector sector-shaped microstrip bias circuit isolate DC signals from RF signals and provide a stable DC bias voltage. The base voltage V... g Collector voltage V dd Provides the DC conditions for transistor Q2 to conduct.

[0058] In some embodiments, the high-frequency input matching circuit 3 and the low-frequency input matching circuit 4 are both composed of T-type matching networks. By adjusting the lengths of the matching microstrip lines TL8, TL9, TL10, TL18, TL19, and TL20, the negative resistance can be adjusted so that the negative resistance network can compensate for the energy consumed by the load.

[0059] Specifically, the high-frequency input matching circuit 3 includes matching microstrip lines TL8, TL9, and TL10. One end of the high-frequency input DC blocking capacitor C1 is connected to the output terminal of the high-frequency active negative resistance circuit 1, and the other end is connected to one end of the matching microstrip line TL8. The other end of the matching microstrip line TL8 is connected to one end of the matching microstrip line TL9. The other end of the matching microstrip line TL9 is connected to one end of the matching microstrip line TL10. The other end of the matching microstrip line TL10 serves as the output terminal of the high-frequency input matching circuit 3.

[0060] Specifically, the low-frequency input matching circuit 4 includes matching microstrip lines TL18, TL19, and TL20. One end of the low-frequency input DC blocking capacitor C2 is connected to the output terminal of the low-frequency active negative resistor circuit 2, and the other end is connected to one end of the matching microstrip line TL18. The other end of the matching microstrip line TL18 is connected to one end of the matching microstrip line TL19. The other end of the matching microstrip line TL19 is connected to one end of the matching microstrip line TL20. The other end of the matching microstrip line TL20 serves as the output terminal of the low-frequency input matching circuit 4.

[0061] According to the requirements of a reflective oscillator, the active negative resistance network needs to provide energy to the resonator controlling the oscillation frequency and other loads. Therefore, in the design of the active negative resistance network, the active transistors need to generate negative resistance at the corresponding frequency to provide energy for the subsequent energy-dissipating network. Here, Q1 and Q2 are active transistors, and their base voltage V0... g and collector voltage V dd A bias network keeps the transistor in a conducting state; emitter feedback lines TL7 and TL17 are connected to the emitter of the transistor, and base feedback lines TL5, TL6, TL15, and TL16 are connected to the base of the transistor, causing the transistor to operate in an unstable state. By adjusting the lengths of the emitter and base feedback lines, negative resistance can be generated at different frequencies. Choosing a reasonable feedback line length can make the transistor generate negative resistance at the frequency corresponding to the resonator. After generating negative resistance, the magnitude of the negative resistance can be adjusted by adjusting the input matching network. When the negative resistance is too large, the oscillation frequency may shift, so the input matching network needs to be continuously adjusted to obtain a suitable negative resistance.

[0062] Port 1 of the SIW dual-mode dual-frequency radiating resonator is connected to a high-frequency active negative resistance circuit (1). Appropriate TL5, TL6, and TL7 are designed to make the active negative resistance circuit composed of Q1 generate negative resistance near 6.45GHz. The negative resistance is adjusted to a suitable value through the input matching circuit (3). When the circuit satisfies the equivalent input impedance of the negative resistance device... The load impedance at the output of the matching network When the conditions for the start-up of the reflective oscillator are met, the synchronous dual-frequency radiator generates an oscillating radiation signal at 6.45 GHz. Port 2 of the SIW resonator is connected to a low-frequency active negative resistance circuit (2). By designing appropriate TL15, TL16, and TL17, the active negative resistance circuit composed of Q2 generates a negative resistance near 5.70 GHz. The negative resistance is adjusted to a suitable value by the input matching circuit (4), so that the synchronous dual-frequency radiator generates an oscillating radiation signal at 5.70 GHz.

[0063] In the design process of SIW dual-mode dual-frequency radiating resonator, it is necessary to continuously adjust the gap length L along the y-axis. c1 and gap width W c1 Control TE 201 The output of the pattern, the gap length L along the x-axis. c2 and gap width W c2 Control TE 102 The output mode is adjusted, and the length and width of the metal patch at the bottom of the dielectric substrate are adjusted to meet the signal output requirements of the two frequency bands. The gap length L along the y-axis can be observed. c1 The relationship with |S(2,2)| is as follows Figure 6 As shown in (a), the gap width W c1 The relationship with |S(2,2)| is as follows Figure 6 As shown in (b), it can be seen that the length L of the gap is... c1 It has a significant impact on signal output, and the width W of the gap... c1 The impact on signal output is relatively small, and since the gap width cannot be adjusted significantly, it is generally limited to a selected gap width W. c1 After that, no further adjustments were made; instead, the length L of the gap was adjusted. c1 The amount of coupling that affects the signal, L c2 and W c2 The value of L c1 and W c1 Similarly, based on the above theory, by continuously adjusting the length and width of the gap and the size of the patch, the simulation results of the final SIW dual-mode dual-frequency radiating resonator design example are as follows: Figure 7As shown, |S(1,1)| and |S(2,2)| represent the two return losses of the two-port SIW dual-mode dual-frequency radiating resonator. The minimum low-frequency return loss is 5.70 GHz, with a return loss of -37.50 dB; the minimum high-frequency return loss is 6.45 GHz, with a return loss of -31.71 dB. |S(2,1)| represents the isolation between the two ports. Thanks to the design of the equal-amplitude, in-phase T-type power divider as the feeder, the isolation between the two ports is maintained below -35 dB within the operating frequency band. This allows the SIW dual-mode dual-frequency radiating resonator provided in this example to be used as a dual-frequency radiator with high isolation and low insertion loss. The microwave synchronous dual-frequency radiator designed based on this SIW dual-mode dual-frequency radiating resonator can have high output power and good spectral purity.

[0064] like Figure 8 The diagram shows the far-field radiation patterns of a SIW dual-mode dual-frequency radiating resonator operating at low and high frequencies, respectively. The radiation direction of the radiating resonator is downward, indicating good radiation performance. Figure 8 (a) is mainly composed of workers in TE 201 The low-frequency signal in the mode is excited through a gap along the y-axis. Figure 8 (b) is mainly composed of workers in TE 102 In this mode, a high-frequency signal is excited through a slit along the x-axis to achieve a gain such as Figure 9 As shown. To distinguish between vertical and horizontal polarization, we artificially define the +X direction as the "vertical polarization" reference direction when φ is 0 degrees. Therefore, the rETheta component represents the vertical polarization component, and the rEPhi component represents the horizontal polarization component. For example... Figure 10 (a)- Figure 10 As shown in (b), since the low-frequency components operate at TE... 201 In this mode, the electric field distribution within the cavity exhibits two half-wave variations along the y-axis, while the electric field vector primarily travels along the x-axis. Therefore, it radiates into free space via coupling through a slit along the y-axis, achieving vertical polarization signal radiation. The high-frequency components operate at TE... 102 In this mode, the electric field distribution within the cavity exhibits two half-wave variations along the x-axis, while the electric field vector is primarily along the y-axis. Consequently, it radiates into free space via coupling through a slit along the x-axis, thus achieving the radiation of a horizontally polarized signal.

[0065] To understand the electromagnetic energy radiated by a microwave simultaneous dual-frequency miniaturized radiator in air, we introduced a conventional slot-coupled receiving patch antenna below the radiator to measure the radiated signal. Since the slot directions corresponding to the two operating modes are perpendicular to each other, the polarization directions of the radiated electric field are also orthogonal. Therefore, this invention can simultaneously achieve the radiation of two mutually orthogonal dual-frequency signals within the same radiating structure. At the receiving end, because the horizontally and vertically polarized signals are independent in space and have high polarization isolation, the receiving system can effectively distinguish the two frequency band signals through polarization separation technology, thereby avoiding inter-band interference and improving signal quality. The final results are as follows: Figure 11 As shown, the return loss of the radiating resonator under both parallel conditions is less than -15dB, where Figure 11 (a) shows the received low-frequency component from the vertical polarization direction, with a transmission loss of -13.53 dB at 5.70 GHz. Figure 11 (b) shows the high-frequency component received from the horizontal polarization direction, with a transmission loss of -15.78 dB at 6.45 GHz. It is easy to see that the isolation of the main polarization component of the two polarization signals received by the receiving antenna from the cross-polarization component is above -30 dB.

[0066] like Figure 12 The figure shows the radiated signal spectrum results of a microwave simultaneous dual-frequency miniaturized radiator design example. The dashed line corresponds to the received low-frequency oscillating radiation signal from the vertical polarization direction, with an oscillation frequency of 5.74 GHz and a received power of -9.887 dBm; the solid line corresponds to the received high-frequency oscillating radiation signal from the horizontal polarization direction, with an oscillation frequency of 6.50 GHz and an output power of -14.409 dBm. Since the SIW dual-mode dual-frequency radiating resonator designed in this study can simultaneously radiate signals in both vertical and horizontal polarization directions, electromagnetic simulation results based on HFSS also demonstrate that the two polarization modes maintain essentially independent radiation characteristics, with almost no significant interference between them. Therefore, we can see that in the subsequent ADS circuit-level simulation, the microwave simultaneous dual-frequency miniaturized radiator implemented using the above two operating frequencies also exhibits good independence and non-interference characteristics in its radiated oscillation signals, thus verifying the feasibility and effectiveness of this structure in dual-polarization signal applications.

[0067] like Figure 13 (a)- Figure 13As shown in Figure (b), the output signal phase noise results of a simultaneous dual-frequency radiator design example are presented. At a frequency offset of 1 MHz, the phase noise at the 5.74 GHz oscillation frequency is -149.47 dBc / Hz, and the phase noise at the 6.50 GHz oscillation frequency is -145.27 dBc / Hz. It can be seen that the microwave simultaneous dual-frequency miniaturized radiator manufactured in this invention has good phase noise in its oscillation signal, meeting the design objectives.

[0068] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A microwave synchronous dual-frequency miniaturized radiator, characterized in that, include: High-frequency active negative resistance circuit (1), high-frequency input DC blocking capacitor C1, low-frequency active negative resistance circuit (2), low-frequency input DC blocking capacitor C2, high-frequency input matching circuit (3), low-frequency input matching circuit (4), SIW dual-mode dual-frequency radiating resonator (5); the input terminal of the high-frequency active negative resistance circuit (1) is connected to the collector voltage V. dd and base voltage V g The output terminal is connected to one end of the high-frequency input DC blocking capacitor C1; the other end of the high-frequency input DC blocking capacitor C1 is connected to the input terminal of the high-frequency input matching circuit (3); the input terminal of the low-frequency active negative resistance circuit (2) is connected to the collector voltage V. dd and base voltage V g The output terminal is connected to one end of the low-frequency input DC blocking capacitor C2; the other end of the low-frequency input DC blocking capacitor C2 is connected to the input terminal of the low-frequency input matching circuit (4); the output terminal of the high-frequency input matching circuit (3) and the output terminal of the low-frequency input matching circuit (4) are respectively connected to the two input terminals of the SIW dual-mode dual-frequency radiating resonator (5); The SIW dual-mode dual-frequency radiating resonator (5) comprises, from top to bottom, a top metal layer (6), a first dielectric substrate (7), a metal ground plane (8), a second dielectric substrate (9), and a bottom metal layer (10). The first dielectric substrate (7) has multiple periodically distributed first metal vias, which form a closed structure except at the power supply point, and the two ends of the first metal vias are respectively connected to the top metal layer (6) and the metal ground plane (8). The second dielectric substrate (9) has multiple periodically distributed second metal vias, which form a closed structure, and the second metal vias are corresponding to the first metal vias, and the two ends of the first metal vias are respectively connected to the metal ground plane (8) and the bottom metal layer (10). The top metal layer (6), the first dielectric substrate (7), the metal ground plane (8), and the first metal vias constitute the SIW resonator, and the second dielectric substrate (9), the bottom metal layer (10), and the second metal vias constitute the radiator.

2. The microwave synchronous dual-frequency miniaturized radiator according to claim 1, characterized in that, The top metal layer (6) includes a rectangular metal patch (61) and two equal-amplitude, in-phase T-type power dividers (62); the two T-type power dividers (62) are respectively connected to two adjacent sides of the rectangular metal patch (61).

3. The microwave synchronous dual-frequency miniaturized radiator according to claim 2, characterized in that, The two branch arms of the T-type power divider (62) are connected to rectangular metal patches (61), and the converging arm serves as a signal input port.

4. The microwave synchronous dual-frequency miniaturized radiator according to claim 1, characterized in that, The length and width of the rectangular metal patch (61) are both smaller than the first dielectric substrate (7); the length and width of the metal ground plate (8) are equal to the first dielectric substrate (7).

5. The microwave synchronous dual-frequency miniaturized radiator according to claim 1, characterized in that, The first metal through hole is provided along the edge of the rectangular metal patch (61).

6. The microwave synchronous dual-frequency miniaturized radiator according to claim 1, characterized in that, The metal floor (8) has a cross-shaped slit (81) at its center, which falls inside the resonant cavity and does not contact the first metal through hole.

7. The microwave synchronous dual-frequency miniaturized radiator according to claim 1, characterized in that, The aspect ratio of the SIW resonator is less than 1.

5.

8. A microwave synchronous dual-frequency miniaturized radiator according to claim 6, characterized in that, A rectangular notch (101) is opened in the center of the bottom metal layer (10), and the rectangular notch (101) falls inside the resonant cavity; a radiating patch (102) is disposed inside the rectangular notch (101) and does not contact the bottom metal layer (10).

9. A microwave synchronous dual-frequency miniaturized radiator according to claim 8, characterized in that, The projection center of the cross-shaped slit (81) on the bottom metal layer (10) coincides with the center of the radiating patch (102).

10. A microwave synchronous dual-frequency miniaturized radiator according to claim 1, characterized in that, Two transistors are used to construct a high-frequency active negative resistance circuit (1) and a low-frequency active negative resistance circuit (2) to compensate for the energy loss of the SIW resonator. The oscillation signal of the SIW resonator is radiated out by coupling the bottom metal layer (10) through the cross slot gap (81). The SIW resonator is based on a dual-mode design and can simultaneously excite TE in a single resonant cavity. 201 and TE 102 Two modes.

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