A dual-polarized aperture-coupled magneto-electric (ME) dipole antenna is proposed. Two separate substrate-integrated waveguides (SIWs) implemented in two printed circuit board (PCB) laminates are used to feed the antenna. The simulated $- {10}$ -dB impedance bandwidth of the antenna is 21% together with an isolation of over 45 dB between the two input ports. Good radiation characteristics, including almost identical unidirectional radiation patterns in two orthogonal planes, front-to-back ratio larger than 20 dB, cross-polarization levels less than $- {23}\;{\text{dB}}$ , and a stable gain around 8 dBi over the operating band, are achieved. By employing the proposed radiating element, a ${2} \times {2}$ wideband antenna array working at the 60-GHz band is designed, fabricated, and tested, which can generate two-dimensional (2-D) multiple beams with dual polarization. A measured $- {10}\;\text{dB}$ impedance bandwidth wider than 22% and a gain up to 12.5 dBi are obtained. Owing to the superiority of the ME dipole, the radiation pattern of the array is also stable over the operating frequencies and nearly identical in two orthogonal planes for both of the polarizations. With advantages of desirable performance, convenience of fabrication and integration, and low cost, the proposed antenna and array are attractive for millimeter-wave wireless communication systems.

60-GHz Dual-Polarized Two-Dimensional Switch-Beam Wideband Antenna Array of Aperture-Coupled Magneto-Electric Dipoles

In this paper, high-performance $W$ -band substrate integrated waveguide (SIW) filters have been investigated by using the low-cost printed-circuit-board (PCB) technology. Two types of SIW bandpass filters including cascaded quadruplet (CQ) and cascaded triplet (CT) filters were studied. The coupling matrix theory has been used to synthesize initial geometries, and the aggressive space mapping (ASM) algorithm was adopted as fast and low computation cost optimization method for realizations of investigated filters. A fin-line SIW-WR10 waveguide transition was developed for experiments. As demonstrations, two $W$ -band prototypes having a 2.5% fractional bandwidth centered at 80 GHz were fabricated on a 0.508-mm-thick RO5880 substrate and measured by a vector network analyzer. Good agreement between simulated and measured results is obtained. This work demonstrates that high-performance $W$ -band planar filters can be realized by utilizing the low-cost commercial PCB technology, and some design rules are recommended.

Developing Low-Cost $W$ -Band SIW Bandpass Filters Using the Commercially Available Printed-Circuit-Board Technology

A simple right-angle transition between a rectangular waveguide (RWG) and a substrate integrated waveguide (SIW) is proposed. Two slots etched on the broad wall of the SIW are used to couple the waveguides. To obtain a wide bandwidth of operation the slots have different lengths to create a double resonance behaviour. The proposed component has a simple mechanical configuration with the flange of the standard RWG flush-mounted to the substrate of the SIW. A sample transition is designed to work in the lower part of the Ka-band. The experimental results agree well with numerical predictions. The proposed component has 6.6% bandwidth and insertion loss below 0.5 dB.

Broadband Ka-band rectangular waveguide to substrate integrated waveguide transition

A broadband air-filled rectangular waveguide to substrate integrated waveguide (SIW) transition is proposed at V-band. By introducing an aperture coupled patch antenna structure into the design, a bandwidth wider than 35% for |S
 11
| <; -10 dB is achieved. A back-to-back prototype fabricated by the low-cost printed circuit board (PCB) technology shows that the insertion loss of a single transition is less than 0.58 dB within the bandwidth. With good performance and compact volume, the proposed transition is attractive for millimeter-wave circuit designs and measurements.

A Broadband V-Band Rectangular Waveguide to Substrate Integrated Waveguide Transition

A single-layer right-angle broadband transition between the substrate-integrated waveguide and air-filled standard rectangular waveguide is proposed and demonstrated at the V-band. An aperture coupled patch with two pairs of inductive posts is employed to form the transition. An impedance bandwidth wider than 48% for return loss less than −10 dB is achieved. The proposed back-to-back transition is fabricated on a single layer substrate using the printed circuit board technology. The measured results of back-to-back prototype show that the insertion loss of a single transition is less than 0.5 dB. The measured results show a good agreement with HFSS simulation results. This transition with compact size, wide bandwidth, and low cost can be used for a variety of millimeter-wave circuits and systems.

Broadband Transition of Substrate-Integrated Waveguide-to-Air-Filled Rectangular Waveguide

A novel broadband transition from a substrate integrated waveguide to a rectangle waveguide with an antipodal fin-line in its quasi-TE mode is presented. Impedance match and field mode gradual changing of transition circuits have been carefully analysed and performed. Experimental results show about a 1.6 dB insertion loss and greater than 12 dB return loss for back-to-back transitions over 10 GHz bandwidth from 26.5 to 40 GHz, so single transition insertion loss is about 0.8 dB. The transition is proposed for low-loss front-end circuits in the millimetre-wave band.

Broadband substrate integrated waveguide to rectangular waveguide transition with fin-line

Silicon based optoelectronic integrated optical phased array is attractive owing to large-dense integration, large scanning range and CMOS compatibility. In this paper, we design and fabricate a SiN-on-SOI two-dimensional optical phased array chip. We demonstrate a two-dimensional scanning range of 96°×14.4° and 690 mW peak power of the main lobe. Additionally, we set up the time of flight (ToF) and frequency-modulated continuous-wave (FMCW) ranging systems by using this optical phased array chip, and achieve the objects detection at the range of 20 m in the ToF system and 109 m in the FMCW system, respectively.

Two-dimensional multi-layered SiN-on-SOI optical phased array with wide-scanning and long-distance ranging.

A broadband transition between a half mode substrate integrated waveguide and a rectangular waveguide with an antipodal fin-line in its quasi-TEM mode is presented Experimental results show about 13 dB insertion loss and below −15 dB return loss for a back-to-back double transition over 10 GHz bandwidth from 265 to 40 GHz (the single transition insertion loss is about 065 dB) The transition may be used in low-loss and low-noise front-end circuits of the microwave and millimetre-wave bands

Broadband transition between half mode substrate integrated waveguide and rectangular waveguide

Germanium-on-silicon (Ge-on-Si) avalanche photodiodes (APDs) are widely used in near-infrared detection, laser ranging, free space communication, quantum communication, and other fields. However, the existence of lattice defects at the Ge/Si interface causes a high dark current in the Ge-on-Si APD, degrading the device sensitivity and also increasing energy consumption in integrated circuits. In this work, we propose a novel surface illuminated Ge-on-Si APD architecture with three terminals. Besides two electrodes on Si substrates, a third electrode is designed for Ge to regulate the control current and bandwidth, achieving multiple outputs of a single device and reducing the dark current of the device. When the voltage on Ge is <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m1"> <mml:mrow> <mml:mo form="prefix">−</mml:mo> <mml:mn>27.5</mml:mn> <mml:mtext> </mml:mtext> <mml:mi mathvariant="normal">V</mml:mi> </mml:mrow> </mml:math> , the proposed device achieves a dark current of 100 nA, responsivity of 9.97 A/W at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m2"> <mml:mrow> <mml:mo form="prefix">−</mml:mo> <mml:mn>40</mml:mn> <mml:mtext> </mml:mtext> <mml:mi>dBm</mml:mi> </mml:mrow> </mml:math> input laser power at 1550 nm, and optimal bandwidth of 142 MHz. The low dark current and improved responsivity can meet the requirements of autonomous driving and other applications demanding weak light detection. 

A Novel Three-Terminal Germanium-on-Silicon Avalanche Photodiode with Extended p-charge layer for Dark Current Reduction

Abstract Bessel beam featured with self-healing is essential to the optical sensing applications in the obstacle scattering environment. Integrated on-chip generation of the Bessel beam outperforms the conventional structure by small size, robustness, and alignment-free scheme. However, the maximum propagation distance (Z max ) provided by the existing approaches cannot support long-range sensing, and thus, it restricts its potential applications. In this work, we propose an integrated silicon photonic chip with unique structures featured with concentrically distributed grating arrays to generate the Bessel–Gaussian beam with a long propagation distance. The spot with the Bessel function profile is measured at 10.24 m without optical lenses, and the photonic chip’s operation wavelength can be continuously performed from 1500 to 1630 nm. To demonstrate the functionality of the generated Bessel–Gaussian beam, we also experimentally measure the rotation speeds of a spinning object via the rotational Doppler Effect and the distance through the phase laser ranging principle. The maximum error of the rotation speed in this experiment is measured to be 0.05%, indicating the minimum error in the current reports. By the compact size, low cost, and mass production potential of the integrated process, our approach is promising to readily enable the Bessel–Gaussian beam in widespread optical communication and micro-manipulation applications. 

/pdf/on-chip-generation-of-bessel-gaussian-beam-via-2lysglpq.pdf

Z.Y. Zhi

Papers

Broadband substrate integrated waveguide to rectangular waveguide transition with fin-line

Two-dimensional multi-layered SiN-on-SOI optical phased array with wide-scanning and long-distance ranging.

Broadband transition between half mode substrate integrated waveguide and rectangular waveguide

A Novel Three-Terminal Germanium-on-Silicon Avalanche Photodiode with Extended p-charge layer for Dark Current Reduction

On-chip generation of Bessel–Gaussian beam via concentrically distributed grating arrays for long-range sensing