CN108832291A - A substrate integrated waveguide filter antenna - Google Patents

Abstract

The invention relates to a substrate-integrated waveguide filter antenna, which belongs to the technical field of filter antennas. The antenna includes upper and lower dielectric substrates, metal through holes, metal coupling probes, complementary split resonant rings, excitation sources and grounding plates; upper and lower layers The surface of the dielectric substrate is rectangular, and the upper and lower dielectric substrates are closely attached. The upper surface of the upper dielectric substrate is provided with a grounding plate, and the upper and lower surfaces of the lower dielectric substrate are provided with a grounding plate; metal through holes are used to connect the upper and lower dielectric substrates. The metal walls that form the upper and lower resonant cavities on the substrate; the complementary split resonant ring is etched on the ground plate on the upper surface of the upper dielectric substrate; the metal coupling probe is used to connect the metal ground plate on the lower surface of the lower dielectric substrate and the upper dielectric substrate Metal ground plane on the surface; the excitation source consists of sequentially connected 50-ohm microstrip lines, coplanar waveguides and rectangular slots. The filter antenna of the invention has good matching, good out-of-band suppression and flat passband gain.

Description

A substrate integrated waveguide filter antenna

technical field

The invention belongs to the technical field of filter antennas and relates to a substrate integrated waveguide filter antenna.

Background technique

In recent years, with the development of miniaturization and compactness of communication equipment, RF front-end devices are required to be multifunctional. Antennas and filters are important components of the RF front-end, and their integrated and integrated design has received extensive attention. The design of filter antenna with out-of-band suppression has become a current research hotspot.

Contents of the invention

In view of this, the object of the present invention is to provide a kind of substrate integrated waveguide filter antenna with good out-of-band suppression function and flat passband gain, and realize antenna profile height is low simultaneously, and size is compact, and it is easy to integrate with other planar circuits integration purpose.

To achieve the above object, the present invention provides the following technical solutions:

A substrate-integrated waveguide filter antenna, which includes upper and lower dielectric substrates, metal through holes, metal coupling probes, complementary split resonant rings, excitation sources and grounding plates;

The surfaces of the upper and lower dielectric substrates are rectangular, and the upper and lower dielectric substrates are closely attached up and down, the upper surface of the upper dielectric substrate is provided with a grounding plate, and the upper and lower surfaces of the lower dielectric substrate are provided with grounding plates;

The metal through holes are used to form the metal walls of the upper and lower resonant cavities on the upper and lower dielectric substrates. The positions of the metal through holes of the upper and lower dielectric substrates are asymmetrical, and the metal through holes constituting the upper resonant cavity penetrate through The upper dielectric substrate and its grounding plate are distributed in a straight line around the upper dielectric substrate, the upper dielectric substrate and its grounding plate, the metal through holes of the upper dielectric substrate, and the grounding plate on the upper surface of the lower dielectric substrate constitute the Upper resonant cavity;

The metal through holes constituting the lower resonant cavity run through the lower dielectric substrate and the grounding plates on its upper and lower surfaces, and are distributed in a straight line around the lower dielectric substrate, and the lower dielectric substrate and the grounding plates on its upper and lower surfaces , the metal through holes of the lower dielectric substrate constitute the lower resonant cavity;

The complementary split resonant ring is etched on the ground plate on the upper surface of the upper dielectric substrate, the complementary split resonant ring is not closed, and the complementary split resonant ring is arranged around the metal through hole close to the upper dielectric substrate;

The metal coupling probe penetrates from the ground plate on the lower surface of the lower dielectric substrate to the ground plate on the upper surface of the upper dielectric substrate, and the metal coupling probe is located close to the gap of the resonant ring with complementary gaps to connect the metal ground on the lower surface of the lower dielectric substrate. Metal ground plate on the upper surface of the floor and upper dielectric substrate;

The excitation source includes sequentially connected 50-ohm microstrip lines, coplanar waveguides and rectangular slots, and the 50-ohm microstrip lines, coplanar waveguides and rectangular slots are arranged on the ground plate on the lower surface of the lower dielectric substrate from outside to inside superior.

Further, the upper and lower dielectric substrates are squares with a side length of 68 mm, the same size, and a thickness of 1.575 mm. The three layers of ground plates completely cover the surfaces of the upper and lower dielectric substrates.

Further, the radius of the metal through holes of the upper dielectric substrate is 0.5mm, and the distance between the centers of the metal through holes is 1.7mm; the radius of the metal through holes of the lower dielectric substrate is 0.5mm, and the distance between the centers of the metal through holes is 1.8 mm. mm.

Further, the length of the wide-side slit of the complementary slit resonant ring is 42.6 mm, the width of the wide-side slit is 0.8 mm, the length of the narrow-side slit is 33.6 mm, and the width of the narrow-side slit is 1.5 mm. The center of the side is symmetrical, and the length of the gap is 3mm.

Further, the radius of the metal coupling probe is 0.3 mm, the gap between the metal coupling probe and the complementary split resonant ring is 12.1 mm on the wide side, and the narrow side gap is 1.7 mm.

Further, the rectangular groove is mirror-symmetrical to the central axis of the coplanar waveguide feeder line, the length of the 50 ohm microstrip line is 10.5mm, and the width is 3mm, the length of the coplanar waveguide is 15.7mm, and the width is 3mm, and the gap of the coplanar waveguide The width is 0.5mm, the length of the rectangular slot is 4.5mm, and the width is 1.3mm.

The beneficial effects of the present invention are:

1. By constructing resonant cavities on two vertically placed dielectric substrates, the coupling of electromagnetic energy is realized through metal coupling probes between the two resonators, thereby introducing the function of filtering. In order to form effective electromagnetic energy radiation, adopt A complementary split resonant ring is etched on the upper metal surface of the upper dielectric substrate.

2. The filter antenna is well matched, and has good out-of-band rejection and flat passband gain. The peak gain reaches 6.7dBi, and the -10dB impedance bandwidth exceeds 6%, so that the filter antenna can be applied to complex electromagnetic signal environments.

3. The filter antenna has a compact structure with a section height of only 0.03λ ₀ , which is easy to process and integrate.

Description of drawings

In order to make the purpose, technical scheme and beneficial effect of the present invention clearer, the present invention provides the following drawings for illustration:

Fig. 1 is a three-dimensional view of the overall structure of the filter antenna of the present invention;

Fig. 2 is the top view of the upper metal ground plate of the filter antenna of the present invention;

Fig. 3 is the top view of the middle metal ground plate of the filter antenna of the present invention;

Fig. 4 is the top view of the metal ground plate of the lower floor of the filter antenna of the present invention;

Fig. 5 is the S parameter of filter antenna of the present invention and achievable gain graph;

Fig. 6 is a radiation field diagram of the E plane and the H plane at the center frequency point of the filter antenna of the present invention.

Detailed ways

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

A substrate-integrated waveguide filter antenna, including two dielectric substrates 1, 2, metal through holes 6, metal coupling probes 8, complementary split resonant ring 7, excitation source, grounding plate and other structures; the two dielectric substrates are vertically compact Bonding, the upper and lower surfaces of the lower dielectric substrate 2 are provided with metal grounding plates 4, 5, while the upper dielectric substrate 1 is only provided with a metal grounding plate 3 on the upper surface; metal through holes 6 are used to connect the upper and lower substrates respectively. The upper part constitutes the metal wall of the resonant cavity, the lower cavity consists of the lower dielectric substrate 2, the grounding plates 4, 5 on the upper and lower surfaces of the lower dielectric substrate 2, and the surrounding metal through holes 6, and the upper cavity consists of the upper dielectric substrate 1, the upper dielectric The ground plate 3 on the upper surface of the substrate 1, the ground plate 4 on the upper surface of the lower dielectric substrate 2, and the surrounding metal through holes 6; the metal coupling probe 8 is used to connect the ground plate on the lower surface of the lower dielectric substrate and the upper surface of the upper dielectric substrate 1 The ground plate 3; the complementary gap resonant ring 7 is etched on the upper surface metal ground plate of the upper dielectric substrate; the excitation source is composed of 50 ohm microstrip line 9, coplanar waveguide feeder line 10 and etched on the lower surface ground plate of the lower dielectric substrate It consists of two rectangular slots 11 symmetrical to the center of the coplanar waveguide feeder line.

The two dielectric substrates are vertically attached tightly, and the upper and lower surfaces of the lower dielectric substrate are provided with grounding plates. The size of the grounding plate on the lower surface is 68mm×58mm, the size of the grounding plate on the upper surface is 68mm×68mm, and the size of the corresponding dielectric substrate is 68mm×68mm , the thickness is 1.575mm, the upper surface of the upper dielectric substrate is provided with a grounding plate, the size of the upper surface grounding plate is 68mm×68mm, the size of the corresponding dielectric substrate is 68mm×68mm, and the thickness is 1.575mm.

Two upper and lower resonant cavities composed of metal through holes. The upper resonant cavity is composed of the upper dielectric substrate, the upper surface grounding plate of the upper dielectric substrate, the upper surface grounding plate of the lower dielectric substrate, and the metal through holes in the upper dielectric substrate. The metal through holes The radius is 0.5mm, and the distance between the centers of metal through holes is 1.7mm. The lower resonant cavity is composed of the lower dielectric substrate, the upper and lower surface grounding plates of the lower dielectric substrate, and the metal through holes in the lower dielectric substrate. The radius of the metal through hole is 0.5mm. The center-to-center spacing of the through-holes is 1.8mm.

The complementary split resonant ring is etched on the grounding plate on the upper surface of the upper dielectric substrate. The length of the gap on the wide side is 42.6 mm, the width of the gap is 0.8 mm, the length of the slot on the narrow side is 33.6 mm, and the width of the gap is 1.5 mm. The position of the gap is on the narrow side. The center of the narrow side is symmetrical, and the length of the gap is 3mm.

The metal coupling probe runs through the ground plate on the lower surface of the lower dielectric substrate to the upper surface ground plate of the upper dielectric substrate. The position of the metal coupling probe is close to the gap of the complementary gap resonant ring. The radius of the metal coupling probe is 0.3mm, and the distance between the metal coupling probe is complementary The nearest wide-side gap of the split resonant ring is 12.1mm, and the narrow-side gap is 1.7mm.

The excitation source consists of a 50-ohm microstrip line, a coplanar waveguide feeder line, and two rectangular slots etched on the ground plate on the lower surface of the lower dielectric substrate, which are symmetrical to the center of the coplanar waveguide feeder line. The length of the corresponding 50-ohm microstrip line is 10.5mm. The width is 3mm, the length of the coplanar waveguide is 15.7mm, the width is 3mm, the slot width is 0.5mm, the length of the rectangular slot is 4.5mm, and the width is 1.3mm.

specific embodiment

1 is a three-dimensional view of the overall structure of the filter antenna of the present invention, as shown in the figure: the filter antenna of the present invention includes an upper dielectric substrate 1, a lower dielectric substrate 2, an upper metal ground plate 3, a middle metal ground plate 4, and a lower metal ground plate. Floor 5, metal via 6, complementary split resonant ring 7, metal coupling probe 8, 50 ohm microstrip line 9, coplanar waveguide 10, rectangular slot 11.

The thickness of the upper dielectric substrate 1 is 1.575 mm, the upper surface of the substrate is close to the upper metal ground plate 3, the lower surface of the substrate is close to the middle metal ground plate 4, the complementary split resonant ring is etched on the upper metal ground plate 3, and the upper resonant cavity is formed by The upper dielectric substrate 1 , the upper metal ground plate 3 , the middle metal ground plate 4 , and metal through holes, the metal coupling probe 8 directly connects the lower metal ground plate 5 and the upper metal ground plate 3 .

The thickness of the lower dielectric substrate 2 is 1.575mm. The upper surface of the substrate is close to the middle metal ground plate 4, and the lower surface is close to the lower metal ground plate 5. The lower resonant cavity is composed of the lower dielectric substrate 2, the middle metal ground plate 4, and the lower metal ground plate. The floor 5, the metal through-hole group layer, the excitation source is composed of a 50 ohm microstrip line 9, a coplanar waveguide 10, and a rectangular slot 11.

The two dielectric substrates, the upper dielectric substrate 1 and the lower dielectric substrate 2, are vertically and tightly bonded. The material is TheRogers Duroid 5880, the relative permittivity is 2.2, the relative permeability is 1.0, and the loss tangent is 0.0009.

The metal ground plate and the 50-ohm microstrip line metal strips are all copper-clad films with the same thickness.

After completing the above initial design, use the high-frequency electromagnetic simulation software HFSS13.0 for simulation analysis. After simulation optimization, the parameters and sizes are obtained as shown in the following table:

Referring to accompanying drawings 2, 3 and 4, W1 and L1 represent the width and length of the lower resonant cavity respectively, W2 and L2 represent the width and length of the upper resonant cavity respectively, and Wp and Lp represent the width and length of the complementary split resonant ring respectively , gy and gx respectively represent the gap width of the complementary split resonant ring, d and s represent the distance between the metal vias and the metal vias respectively, p represents the diameter of the metal coupling probe, fw represents the width of the coplanar waveguide, and pw represents Coplanar waveguide slot width, mw, ml represent the width and length of the rectangular slot.

Table 1 The optimal size table of each parameter of the present invention

According to the above parameters, HFSS is used to simulate and analyze the reflection coefficient |S ₁₁ | characteristic parameters and achievable gain of a substrate-integrated waveguide filter antenna designed. The analysis results are as follows:

Fig. 5 is a graph of S parameters and achievable gain varying with frequency obtained from the simulation of the present invention. As shown in the figure, the working frequency band of the antenna involved is 2.855GHz to 3.040GHz, the resonance center frequency is 2.95GHz, and the -10dB bandwidth is 185MHz; it can be seen from the achievable gain curve that the achievable gain curve has a good out-of-band Suppression function, the maximum gain is 7.18dBi, and the gain in the passband is relatively flat. Figure 6 is the radiation pattern of the simulated antenna on the E plane and the H plane respectively at the resonant frequency point of 2.95 GHz. It can be seen from the figure that the antenna has good side-firing radiation characteristics.

Finally, it is noted that the above preferred embodiments are only used to illustrate the technical solutions of the invention and not limit them. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that it may be possible in form and details. Various changes can be made to it without departing from the scope defined by the claims of the present invention.

Claims (6)

1. A substrate-integrated waveguide filter antenna, characterized in that: the antenna comprises upper and lower dielectric substrates, metal vias, metal coupling probes, complementary gap resonant rings, excitation source and ground plate; The surfaces of the upper and lower dielectric substrates are rectangular, and the upper and lower dielectric substrates are closely attached up and down, the upper surface of the upper dielectric substrate is provided with a grounding plate, and the upper and lower surfaces of the lower dielectric substrate are provided with grounding plates; The metal through holes are used to form the metal walls of the upper and lower resonant cavities on the upper and lower dielectric substrates. The positions of the metal through holes of the upper and lower dielectric substrates are asymmetrical, and the metal through holes constituting the upper resonant cavity penetrate through The upper dielectric substrate and its grounding plate are distributed in a straight line around the upper dielectric substrate, the upper dielectric substrate and its grounding plate, the metal through holes of the upper dielectric substrate, and the grounding plate on the upper surface of the lower dielectric substrate constitute the Upper resonant cavity; The metal through holes constituting the lower resonant cavity run through the lower dielectric substrate and the grounding plates on its upper and lower surfaces, and are distributed in a straight line around the lower dielectric substrate, and the lower dielectric substrate and the grounding plates on its upper and lower surfaces , the metal through holes of the lower dielectric substrate constitute the lower resonant cavity; The complementary split resonant ring is etched on the ground plate on the upper surface of the upper dielectric substrate, the complementary split resonant ring is not closed, and the complementary split resonant ring is arranged around the metal through hole close to the upper dielectric substrate; The metal coupling probe penetrates from the ground plate on the lower surface of the lower dielectric substrate to the ground plate on the upper surface of the upper dielectric substrate, and the metal coupling probe is located close to the gap of the resonant ring with complementary gaps to connect the metal ground on the lower surface of the lower dielectric substrate. Metal ground plate on the upper surface of the floor and upper dielectric substrate; The excitation source includes sequentially connected 50-ohm microstrip lines, coplanar waveguides and rectangular slots, and the 50-ohm microstrip lines, coplanar waveguides and rectangular slots are arranged on the ground plate on the lower surface of the lower dielectric substrate from outside to inside superior. 2. A substrate-integrated waveguide filter antenna according to claim 1, characterized in that: the upper and lower dielectric substrates are squares with a side length of 68mm, the same size, and a thickness of 1.575mm. completely cover the surface of the upper and lower dielectric substrates. 3. A substrate-integrated waveguide filter antenna according to claim 1, characterized in that: the radius of the metal through-hole of the upper dielectric substrate is 0.5mm, the distance between the centers of the metal through-holes is 1.7mm, the lower layer The radius of the metal through hole of the dielectric substrate is 0.5 mm, and the distance between centers of the metal through hole is 1.8 mm. 4. A kind of substrate integrated waveguide filter antenna according to claim 1, characterized in that: the length of the broadside slit of the complementary slit resonator ring is 42.6mm, the width of the broadside slit is 0.8mm, and the length of the narrowside slit is 33.6mm, the gap width of the narrow side is 1.5mm, the split position of the complementary split resonant ring is symmetrical about the center of the narrow side, and the split length is 3mm. 5. A substrate-integrated waveguide filter antenna according to claim 4, characterized in that: the radius of the metal coupling probe is 0.3 mm, and the nearest wide-side gap between the metal coupling probe and the complementary split resonant ring is 12.1 mm , The narrow side gap is 1.7mm. 6. A substrate-integrated waveguide filter antenna according to claim 1, wherein the rectangular slot is mirror-symmetrical to the central axis of the coplanar waveguide feeder line, the length of the 50-ohm microstrip line is 10.5 mm, and the width The length of the coplanar waveguide is 15.7mm, the width is 3mm, the slot width of the coplanar waveguide is 0.5mm, the length of the rectangular slot is 4.5mm, and the width is 1.3mm.