Lukui Jin

This letter proposes a wideband vertical transition for multilayer PCBs based on a fuzz button. The discontinuity in the vertical transition is analyzed, and an etched aperture is introduced in the ground plane beneath the connecting pad to compensate for the parasitic capacitance arising from the intentionally oversized pad. This technique extends the concept of chamfering from 2-D microstrip bends to a 3-D chamfer-like design in vertical interconnects. A three-stage transformer is further employed to enhance the impedance matching, enabling the wideband operation from DC to 35 GHz. A back-to-back measurement is conducted for verification, demonstrating a return loss below −10 dB from DC to 33.8 GHz and an insertion loss below 0.5 dB at 30 GHz. The proposed vertical transition offers a promising solution for high-density, removable interconnects in multilayer PCB applications.

In this letter, we propose a shared-aperture antenna composed of a variable inclination continuous transverse stub antenna (VICTS) and a reflectarray (RA) for connecting with Low Earth Orbit (LEO) and Geostationary Earth Orbit (GEO) satellites simultaneously. The VICTS antenna, operating in the K-band, provides a scanning beam, while the RA, operating in the Ku-band, generates a fixed-direction beam. The shared-aperture configuration is realized by positioning the RA above the VICTS antenna. Notably, the RA elements function as a frequency selective surface (FSS) for the VICTS antenna, effectively mitigating mutual interference. A prototype was fabricated and measured to validate the design, good agreement is achieved between the measured and the simulated results.

This paper presents a new design method of digital baseband signal for generating fully digital programmable optical frequency comb (OFC), which solves the problem of how to optimally select the digital baseband signal when OFC is generated by binary digital signal modulation. The inverse Fourier transform is used to study the waveform of binary digital signal which is used to generate OFC. It is found that the number of “0” bits of digital signal determines the flatness of comb lines. Based on this, a tunable ultra‐fine and ultra‐flat OFC was obtained by using a digital signal containing a large number of “0” bits in the experiment. This saves substantial computing time and resources compared to the current method of the k‐means clustering algorithm.

In this paper, a novel Optically Controlled BeamForming Network (OCBFN) is presented. A simplified circuit topology is used, which comprises shared highly reflective Linearly Chirped Fiber Bragg Gratings (LCFBG), to reduce the network complexity while improving optical and electrical performances. The OCBFN also integrates the capability of multiple beams for multiple stream data transmit simultaneously. Theoretical analysis, calculation and an experiment are carried out to verify the concept of OCBFN. Results show that it can realize a dynamic group delay (GD) range of nearly 1000 ps. It is promising for this novel OCBFN to be used in the fields of satellite communications, radar detection/monitoring, etc.

This paper presents a design of dielectric waveguide filter using dual-mode dielectric waveguide resonators (DWRs). The filter is formed by a ceramic monoblock, thus it is compact and ease of fabrication. The employed degenerate modes of DWR are TE101 and TE011 mode, which can be coupled by a slot on the dielectric block. The coupling between a dual-mode DWR and a single-mode DWR is realized by aperture and slot. The external coupling is realized by a silver-coated blind hole that aligns to the mode for excitation. Transmission zero (TZ) can be flexibly generated above or below passband, by changing the relative position of coupling slot. A sixth order bandpass filter working at 4.9 GHz is designed using dual- and single-mode DWRs. The filter is fabricated and measured, agreeing well with simulation. This filter has compact size, low insertion loss, good selectivity and wide spurious-free response, which is applicable to 5G base stations.

This letter presents a triple-quasi-TEM-resonance dielectric cavity for compact bandpass filter design. The proposed dielectric cavity is silver coated and has three blind holes which form three distinct quasi-TEM mode resonators. The external coupling structure for the resonator is realized by tapping hole. The inter-resonator couplings are realized and controlled by slots on the outer surfaces of the dielectric block. A three-pole filter with two controllable transmission zeros is designed and implemented. The measured results agree well with the simulated results, verifying the proposed triple-resonance dielectric cavity structure and coupling mechanisms.