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CN-118645782-B - SSPP-based bandwidth-controllable compact ridge waveguide cavity band-pass filter and manufacturing method thereof

CN118645782BCN 118645782 BCN118645782 BCN 118645782BCN-118645782-B

Abstract

The invention discloses a bandwidth-controllable compact ridge waveguide cavity band-pass filter based on SSPP and a manufacturing method thereof, wherein the device comprises a cavity, a ridge waveguide is arranged in the cavity, a plurality of inverted T-shaped grooves are etched on the ridge waveguide at intervals to form a structure with an artificial surface plasmon polariton SSPP at the middle section, the left end and the right end are structures of the transition artificial surface plasmon polariton SSPP, the structures of the transition artificial surface plasmon SSPP at the left end and the right end are respectively connected with a horizontal coaxial connector, and double grating structures are respectively arranged at the two sides of the ridge waveguide in the cavity. The invention realizes the broadband band-pass structure of 7.6GHz-12.4GHz by integrating the ridge waveguide, the SSPP and the double gratings into one cavity. A return loss below-16 dB and an insertion loss of 0.23dB are achieved in-band. Low loss and small size are achieved over a wide frequency band of 44.8%, and the passband bandwidth can be flexibly tuned.

Inventors

  • CHEN JIANXIN
  • ZHU PENGXU
  • SHI XU

Assignees

  • 南通大学

Dates

Publication Date
20260505
Application Date
20240624

Claims (6)

  1. 1. The bandwidth-controllable compact ridge waveguide cavity band-pass filter based on the SSPP is characterized by comprising a cavity, wherein a ridge waveguide (1) is arranged in the cavity, a plurality of inverted T-shaped grooves (2) are etched on the ridge waveguide (1) at intervals to form a middle section artificial surface plasmon polariton SSPP, the left end and the right end are structures of transition artificial surface plasmon polaritons SSPP, and the structures of the transition artificial surface plasmon SSPP at the left end and the right end are respectively connected with a horizontal coaxial connector (4); the artificial surface plasmon polariton SSPP structure of the middle section is as follows: the inverted T-shaped groove (2) is etched downwards on the ridge waveguide (1), the depth hs is 2mm-4.6mm, the upper width d is 0.4mm-1.2mm, and the lower width ls is 1.5mm-3.3mm; the transition artificial surface plasmon polariton SSPP structure is as follows: The depth hs 1 is 1.5mm-4.1mm, the depth hs 2 is 1mm-3.6mm, and the width d is 0.4mm-1.2mm.
  2. 2. The SSPP-based bandwidth controllable compact ridge waveguide cavity bandpass filter of claim 1, wherein the cavity has dimensions of 30-32mm cavity length L, 12.3-13mm width W and 5.5-6mm height H.
  3. 3. The SSPP-based bandwidth controllable compact ridge waveguide cavity bandpass filter of claim 1, wherein the inverted T-shaped slot (2) has dimensions of: the depth hs of the inverted T-shaped groove is 2mm-4.6mm, the upper width d is 0.4mm-1.2mm, and the lower width ls is 1.5mm-3.3mm.
  4. 4. The SSPP-based bandwidth controllable compact ridge waveguide cavity bandpass filter of claim 1, wherein the dual grating structure (3) is specifically configured as follows: the two sides of the cavity are loaded with stepping grating structures which are the same as the cavity, the length lg of the three grating depths in the middle is 0.8mm-4mm, the width wg is 0.5mm-3mm, and the lengths of the other two sides are gradually reduced according to 0.3 mm.
  5. 5. The SSPP-based bandwidth controllable compact ridge waveguide cavity bandpass filter of claim 1, wherein the filter is made of aluminum metal.
  6. 6. A method for preparing a bandwidth-controllable compact ridge waveguide cavity band-pass filter based on the method in claim 1, comprising the following steps: step 1, determining the sizes of a cavity and internal ridges of a ridge waveguide through the center frequency of a target working frequency band, so that the ridge waveguide works in a TE 10 mode in the target frequency band; step 2, etching a T-shaped groove downwards on the ridge waveguide to realize bandpass characteristics, realizing independent control of upper cut-off frequency by adjusting the depth and width of the groove, and adjusting the determined depth and width of the groove; Step 3, determining the order and the size of the double gratings, and realizing the regulation and control of the lower cutoff frequency by adjusting the order and the extension length of the double gratings; and 4, optimizing the related parameters to achieve the best matching result.

Description

SSPP-based bandwidth-controllable compact ridge waveguide cavity band-pass filter and manufacturing method thereof Technical Field The invention belongs to the field of band-pass filter design, and particularly relates to an SSPP-based bandwidth-controllable compact ridge waveguide cavity band-pass filter and a manufacturing method thereof. Background Artificial surface plasmons (SSPPs) are periodic structures that can support surface wave propagation with short operating wavelengths and near field constraints. SSPP is widely used in the fabrication of bandpass filters based on its natural low-pass characteristics. Existing SSPP filters use microstrip lines, substrate integrated waveguides, rectangular waveguides, gap waveguides, etc. to implement SSPP filter designs. With the development of communication technology, the miniaturization and low loss requirements for bandpass filters are increasing, and waveguide structures are widely used in the design of high frequency systems due to their lower loss and high power capacity. The ridge waveguide has lower cut-off frequency than the waveguide with the same size, so that miniaturization of a circuit is facilitated, and meanwhile, a wider single-mode working bandwidth is obtained. In the prior art, the structure of loading periodic metal strips on a microstrip transmission line and a substrate integrated waveguide has large loss, and the application requirement of low loss is difficult to meet. Meanwhile, loading periodic metal columns in rectangular waveguides and gap waveguides can generate longer transition structures, and the requirements of small size cannot be met. Disclosure of Invention The invention aims to provide an SSPP-based bandwidth-controllable compact ridge waveguide cavity band-pass filter and a manufacturing method thereof. A7.6 GHz-12.4GHz broadband bandpass structure is achieved by integrating the ridge waveguide, SSPP and dual gratings into one cavity. A return loss below-16 dB and an insertion loss of 0.23dB are achieved in-band. Low loss and small size are achieved over a wide frequency band of 44.8% and the bandwidth is flexible to tune. The bandwidth-controllable compact ridge waveguide cavity band-pass filter based on the SSPP comprises a cavity, wherein ridge waveguides are arranged in the cavity, a plurality of inverted T-shaped grooves are etched on the ridge waveguides at intervals to form an artificial surface plasmon polariton SSPP in the middle section, the left end and the right end are structures of transition artificial surface plasmon polaritons SSPP, the structures of the transition artificial surface plasmon polaritons SSPP at the left end and the right end are respectively connected with a horizontal coaxial connector, and double grating structures are respectively arranged at two sides of the ridge waveguides in the cavity. Further, the middle-segment artificial surface plasmon SSPP structure is: The inverted T-shaped grooves are etched down on the ridges, the depth (hs) can vary from 2mm to 4.6mm, the upper width (d) can vary from 0.4mm to 1.2mm, and the lower width (ls) can vary from 1.5mm to 3.3 mm. Further, the transition artificial surface plasmon SSPP structure is: The depth (hs 1) is 1.5mm-4.1mm, the depth (hs 2) is 1mm-3.6mm, and the width (d) is 0.4mm-1.2mm. Further, the size of the cavity is as follows: The length L of the cavity is 30-32mm, the width W is 12.3-13mm and the height H is 5.5-6mm. Further, the inverted T-shaped groove has the following dimensions: The depth (hs) of the inverted T-shaped groove can vary from 2mm to 4.6mm, the upper width (d) can vary from 0.4mm to 1.2mm, and the lower width (ls) can vary from 1.5mm to 3.3 mm. Further, the dual grating structure specifically includes: The two sides of the cavity are loaded with stepping grating structures which are the same as the cavity, the lengths (lg) of the three middle grating depths can be changed between 0.8mm and 4mm, and the widths (wg) can be changed between 0.5mm and 3 mm. The lengths of the other two sides are gradually reduced by 0.3 mm. Further, the filter is made of metal aluminum. The invention also discloses a preparation method of the bandwidth-controllable compact ridge waveguide cavity band-pass filter based on the SSPP, which comprises the following steps: step 1, determining the sizes of a cavity and internal ridges of a ridge waveguide through the center frequency of a target working frequency band, so that the ridge waveguide works in a TE 10 mode in the target frequency band; step 2, etching a T-shaped groove downwards on the ridge waveguide to realize bandpass characteristics, realizing independent control of upper cut-off frequency by adjusting the depth and width of the groove, and adjusting the determined depth and width of the groove; Step 3, determining the order and the size of the double gratings, and realizing the regulation and control of the lower cutoff frequency by adjusting the order and the extension length