In this article, an ultrawideband magnetic probe with high electric field suppression ratio (EFSR) is proposed. The probe has three parts: the loop part, the transmission part, and the head part. Shield metal sheets are designed in the loop part to enhance EFSR. The tapered transmission line in the transmission part and the quasi coaxial transition in the head part are adopted for impedance matching between the induction loop and the grounded coplanar waveguide (GCPW) in the head part. Then, segmented resistance–inductance–capacitance ( RLC ) equivalent circuit models of the probe are proposed for magnetic field coupling and electric field coupling, which are suitable for accurate modeling and efficient optimization of the magnetic probe. In addition, the coupling capacitors between the shield metal sheets and the device under test (DUT) are extracted utilizing the conformal transforming method with analytical formulas. Finally, this magnetic probe is fabricated under printed circuit board (PCB) technology and used in measuring the magnetic field distribution. The measurement and simulation results agree well. The probe has a bandwidth of 100 MHz–30 GHz and an EFSR of higher than 21 dB. Compared with the conventional probe with similar bandwidth, the proposed probe can improve the EFSR by 9 dB.

Substrate integrated coaxial line (SICL) is a kind of planar transmission line, which can guarantee the propagation of transverse electromagnetic mode wave within a wide band. In this paper, a multichannel SICL array with coaxial lines placed in both vertical and horizontal directions is proposed for high-speed parallel data transmission. The adjacent channels of the SICL array share outer conductors for high-density integration. Moreover, the outer conductor is enhanced by metal fence to suppress the crosstalk between adjacent channels of the SICL array. In addition, a quasi-coaxial transition is designed for the proposed SICL array. A systematical design procedure is given to determine the physical dimensions of SICL array with transitions. The SICL array has flat group delay so that data can be transmitted without significant phase distortion. It is suitable for high-density integration and high-speed data transmission due to the low crosstalk and high bandwidth. To verify the advantage of the proposed SICL array, a 15 x 3 channel prototype is designed and fabricated in low temperature co-fired ceramic. The measured S-parameters agree well with the simulated results. The maximum bandwidth of a single channel of the SICL array is up to 56 GHz and the coupling of adjacent channels in the SICL array is less than -30 dB. Data rate of 30 Gb/s is measured for each channel with good eye diagram and low bit error rate, and hence, a total 1.35-Tb/s data rate can be achieved with the proposed 15 x 3 channel SICL array.

In this article, a half-mode substrate integrated waveguide (HMSIW) combined with 2.5-D spoof surface plasmon polaritons (SPPs) structure is proposed to tailor the dispersion features and cutoff frequency of the HMSIW. The proposed HMSIW-SPP structure has a smaller longitudinal dimension since the dispersion of the proposed structure can be tailored by adjusting the geometric parameters of the 2.5-D spoof SPP arbitrary. Simultaneously, the proposed structure has a smaller lateral width than that of the classical HMSIW because the 2.5-D spoof SPP introduces extra capacitance in the waveguide. Moreover, an equivalent circuit model is proposed and used to analyze the design principles. The structure exhibiting the cutoff frequency of 6.0 GHz is designed and fabricated under the printed circuit board process. Measurement and simulation results show that the proposed HMSIW-SPP structure decreases the longitudinal dimension by more than 50% and the lateral width by 25% without sacrificing its transmission performance. Due to the reduced cutoff frequency and effective wavelength, the proposed structure enables extreme miniaturization and can be applied in the design of miniaturized microwave circuits.

An ultra-wideband electric field probe with high sensitivity is proposed for near-field measurement. It consists of the coupling part, the transmission part and the output part. In coupling part, the L-shaped tip and the loaded sensing via are designed to improve the sensitivity. In the output part, the horizontal gradual substrate integrated coaxial line (SICL) to grounded coplanar waveguide (GCPW) transition is designed for good field and impedance matching, resulting in wide bandwidth. In addition, the equivalent circuit is established to explain the mechanism of sensitivity improvement and optimize performance of the proposed probe. The proposed electric field probe is made with printed circuit board (PCB) process and applied to measure the electric near field. The measurement results show that the electric field probe has the bandwidth from 10 MHz to 60 GHz and the spatial resolution of 0.7 mm. In addition, the sensitivity of the proposed electric field probe is about 12 dB higher than that of the conventional monopole electric field probe at the same size of the coupling part.

High-speed link consisting of drivers and interconnects is essential for high-speed data transmission. In this article, a surrogate modeling technique based on graph neural network (GNN) and recurrent neural network (RNN) is proposed for signal integrity (SI) analysis of high-speed links with variable physical parameters and variable topologies. First, GNN extracts global features that can fully characterize components of the high-speed link from their topologies and physical parameters. Second, RNN takes the extracted global features and the excitation waveforms as inputs to predict the response waveforms. Finally, the well-trained GNN-RNN surrogate models of components of the high-speed link are cascaded as the entire surrogate model of the high-speed link. Numerical examples of the dri-ver model, the interconnect model, and the entire high-speed link model are provided for validation. It is shown that the proposed GNN-RNN surrogate models achieve low mean squared errors (MSEs), mean absolute errors (MAEs), and high efficiency.