Yi Zhang’s research while affiliated with University of Electronic Science and Technology of China and other places

... This results in a novel cavity termed the deformed ellipsoidal resonator, as depicted in Figure 2A. The detailed process of creating the new resonator is described in Zhang et al. 28 The length, denoted r d , between the subtracted sphere and target ellipsoid determines both the Q u and the frequency ratio of the first higher-order mode to the fundamental mode (f h /f 0 ). The corresponding plots Q u and f h /f 0 versus r d are presented in Figure 2B. ...

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Three‐dimensional printed X‐band waveguide variable bends with integrated filters

... An advanced solution provides a higher integration and better RF performance, which directly applies rotation to the structures of BPFs, to achieve filtering and bending or twisting simultaneously. Notable studies include a lowpass filter with a 90 • bend and a 90 • twist [15], two 90 • -twisted waveguide BPFs utilizing step-twisted rectangular waveguide resonators [16] and gradually twisted ones [17], and a 90 • benttwisted BPF using gradually distorted rectangular waveguide resonators [18]. And, in [14], BPFs based on elliptical or ellipsoidal resonators are proposed to achieve more flexible waveguide routines. ...

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A 3D-Printed Bent–Twisted Waveguide Filter Using Mixed TE101 and TE102 Mode Resonators

... For rapid experimental validation, filter I was selected to be manufactured by adopting the commercial 3-D metal printing technology, which has revealed the superiority in prototyping microwave/millimeter-wave components [19], [20], [21], [22], [23] with acceptable tolerance. The laser scanning gap is 90 µm, the scanning speed is 1800 mm/s, the laser power is 350 W, and the layer thickness is 35 µm. ...

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Analysis of the Metal Plate Coupled Resonator With Its Compact In-Line Filter Design Applications

... Several works re-port AM of spherical/ellipsoid resonator filters operating at a fundamental TM 101 mode [6]- [10]. A TM 211 mode was used in [11] and [12] to further increase the Q-factor. Recently, a TE 101 mode was used to significantly increase the Q-factor of spherical resonator filters, about 1.67 times compared to the fundamental TM 101 mode at 10 GHz [13], [14]. ...

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Investigation of Metal 3-D Printed High-Q Multiband Waveguide Filters Using Spherical Resonators

... To further facilitate miniaturization of 3D RF BPFs, monolithic metal or plastic-based AM integration concepts are increasingly explored. Metal-based AM processes such as direct laser metal sintering (DLMS) [23] and selective laser melting (SLM) [24] are the most commonly used ones for monolithic integration of spherical resonator-based BPFs [9], [17], [25], [26], [27]. Although a decent performance has been achieved, such processes have high operational costs and lead to high surface roughness (common R a > 15 μm in [28]). ...

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Monolithically-Integrated 3D Printed Bandpass Filters Using Highly-Miniaturized Dome-Shaped Resonators

... An advanced solution provides a higher integration and better RF performance, which directly applies rotation to the structures of BPFs, to achieve filtering and bending or twisting simultaneously. Notable studies include a lowpass filter with a 90 • bend and a 90 • twist [15], two 90 • -twisted waveguide BPFs utilizing step-twisted rectangular waveguide resonators [16] and gradually twisted ones [17], and a 90 • benttwisted BPF using gradually distorted rectangular waveguide resonators [18]. And, in [14], BPFs based on elliptical or ellipsoidal resonators are proposed to achieve more flexible waveguide routines. ...

Reference:

A 3D-Printed Bent–Twisted Waveguide Filter Using Mixed TE101 and TE102 Mode Resonators

... It is common in microstrip based LPFs that using special shaped branches to modify the filter performance. [8][9][10][11][12][13][14] Nevertheless, these empirical shapes are not reliable at higher frequency. The defected ground structure (DGS) is also widely used in PCB-based low frequency LPF, 15 but it may cause energy leakage and signal interference at higher frequency. ...

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A micromachined ultra‐wide stopband lowpass filter based on stepped impedance resonator loaded T‐shaped structure

... DC block capacitors are 2.2 pF, 1.2 pF, and 0.8 pF. Furthermore, the RF choke inductor is 100 nH [25]. Another study presents a new structure for a reconfigurable dual-band stop filter for the tuning extends from the lower and upper band stop at 1.16 to 1.29 GHz and 1.6 to 1.76 GHz. ...

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Design and analysis of reconfigurable filters employing varactor and PIN diodes

... In a traditional filtering antenna design, the antenna and filter are cascaded. This method is simple for design, but does not effectively reduce the size of system [7,8]. In [9][10][11][12], metallic-nail or mushroom-type-based metamaterial surfaces have been applied to the bottom of waveguide to obtain a bandgap that cannot propagate electromagnetic waves. ...

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Wideband filtering waveguide antenna based on the stepped impedance resonator

... To evaluate the performance and structural characteristics of the proposed 2 × 2 subarray antenna, a comparison between the proposed 2 × 2 subarray and previous 2 × 2 subarrays is made in Table 2. A 2 × 2 filtering subarray, which truncated the apertures to achieve high gain and circularly polarized presented in [29], was realised by employing five resonators. However, our design has employed only two resonators and has wider bandwidth and smaller volume. ...

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A NEW 2×2-ELEMENT SUBARRAY ANTENNA SYNTHESIS BASED ON WAVEGUIDE CAVITY RESONATORS