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In this article, a corrugated horn feed antenna with a stable phase center is designed for the millimeter wave compact antenna test range (CATR). The calculation method of the phase center of a horn is analyzed in this article. The 45°‐plane phase center is used as the combined phase center of the horn in order to perform the phase center calculation only once, thus faster, and to optimize the phase performance more conveniently. By adding an absorbing material surrounding the edge of the outer surface of the horn, the irregular currents on the outer surface of the horn are suppressed, thus achieving a more stable phase center. The absorbing material can also reduce the radar cross section of the antenna. The designed corrugated horn works in the 24–40 GHz wide band with the following performances: the deviation of the phase center in the working frequency band is less than ±0.25 mm, the phase variation within a ±30° beam width is less than ±2.5°. Moreover, the measured return loss is lower than −10 dB, the measured gain is 8–12 dBi, and the measured cross‐polarization level is less than −30 dB. The beamwidth is about 56°–70° in the whole band, and the beamwidth difference between different planes is less than 5°. The achieved targets listed above makes the proposed corrugated horn suitable for very precise antenna measurements in CATR systems. [ABSTRACT FROM AUTHOR]

The complexity of electronic systems for RF and digital applications is ever increasing, and the corresponding compliance analysis for ensuring the required specifications in terms of performances, signal and power integrity is a challenging task often accomplished by relying on commercial circuit simulators. The modeling of multiport devices involves the assembly of electrical networks usually described in terms of S‐parameter. This work proposes a new single‐step algorithm that computes the global S‐parameter matrix for a cascade of multiple networks with multiple ports without the need of any S‐parameter transformation in T‐parameters and their inverse transformation. The proposed method involves the construction of a large matrix filled with all S‐parameters of all networks, and the subsequent evaluation of only one matrix expression. The proposed method is shown to be very efficient and reliable, since it can be easily automated without the need of a manual connections of tens or even hundreds of ports of the multiple blocks, which is an action that needs to be performed within a typical circuit simulator environment. Also, the proposed method overcomes the limitation of the standard method based on S‐to‐T parameter transformation since it is of general applicability to networks with different number of input and output ports. Examples involving the cascade of multiple 2‐ports and multiports networks are considered, and the results are validated and compared with the reference results obtained from a commercial circuit simulator. The proposed method is shown to be effective and fast compared to its counterpart based on the T‐parameters. [ABSTRACT FROM AUTHOR]

A compact and highly isolated three-sector linear array is proposed targeting point-to-point or point-to-multipoint data communication in Central Business District (CBD) and residential subdivision applications. It features wide bandwidth, high isolation among the units, low wind load, and low manufacturing and installation costs within the 400–500 MHz band. The driving element of the array unit is a wideband high-efficiency electromagnetic structure (WHEMS) applied in combination with the metal rods as passive elements for isolation purposes. The parasitic rod, shared by the adjacent units, decouples the mutual coupling by reducing the distance, which realizes not only the high isolation capability but also reduced size. The beamwidth and the front-to-back ratio of the antenna are controlled by the combined effect of the metal rods and the bent of the active element. The impedance bandwidth of the antenna is 380–670 MHz (55%), and the H-plane half-power beamwidth (HPBW) is more than 70° in the 380–520 MHz. The front-to-back ratio is more than 19 dB and the gain is 8.2 ± 0.4 dBi in 400–500 MHz. The isolation is greater than 36 dB with unit spacing less than $0.2\lambda $ in 380–670 MHz. [ABSTRACT FROM AUTHOR]

The via-plate capacitance for a via transition to a multilayer printed circuit board is evaluated analytically in terms of higher order parallel-plate modes. The Green's function in a bounded coaxial cavity for a concentric magnetic ring current is first derived by introducing reflection coefficients for cylindrical waves at the inner and outer cavity walls. These walls can be perfect electric conductor (PEC)/perfect magnetic conductor (PMC) or a nonreflective perfectly matched layer. By further assuming a magnetic frill current on the via-hole in the metal plate, an analytical formula is derived for the via barrel-plate capacitance by summing the higher order modes in the bounded coaxial cavity. The convergence of the formula with the number of modes, as well as with the radius of the outer PEC/PMC wall is discussed. The analytical formula is validated by both quasi-static numerical methods and measurements. Furthermore, the formula allows the investigation of the frequency dependence of the via-plate capacitance, which is not possible with quasi-static methods. Index Terms--Analytical formula, Green's function in a coaxial cavity, multilayer package/printed circuit board (PCB), signal integrity, via-holes, via-plate capacitance.