There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Numerical Initial Value Problems in Ordinary Differential Equations

https://digital.csic.es/bitstream/10261/15682/1/blanes.pdf

The Magnus expansion and some of its applications

Introduction to Electromagnetic Compatibility

This paper focuses on a tutorial overview of defected ground structure (DGS). The basic conceptions and transmission characteristics of DGS are introduced and the equivalent circuit models of varieties of DGS units are also presented. Finally, the main applications of DGS in microwave technology field are summarized and the evolution trend of DGS is given.

/pdf/an-overview-on-defected-ground-structure-3dt7yj00ew.pdf

An Overview on Defected Ground Structure

A 120 GHz step-profiled horn antenna integrated in low-temperature co-fired ceramic (LTCC)is presented in this paper. Based on the substrate integrated waveguide technology, the cavities with several surrounding fences of vertical metallic vias are utilized to construct the hollow horn structure in multilayer LTCC substrates. To verify the effectiveness of the design, the proposed antenna prototype is further fabricated and measured. The measured results indicate that more than 8 GHz (115 GHz-123 GHz)bandwidth of 10 dB return loss and a gain of 13.6 dBi in the broadside at 120 GHz are obtained.

A 120 GHz Step-Profiled Horn Antenna in LTCC

Since the miniaturization of microwave passives will increase power density, it is desirable to do a quick and accurate electro-thermal analysis for component design and optimization. In this paper, the multilayer finite-difference method is extended and migrated into the steady-state electro-thermal characterization of substrate integrated waveguide filter in LTCC, while the method was used to analyze the electromagnetic performance of packages and boards. The distributed heat source in the form of conductor and dielectric losses are derived analytically with the coupled resonator circuit model. Then, the temperature distribution is obtained efficiently by solving a linear matrix equation. Our results have been validated by the simulated ones with commercial FEM simulator.

Multilayered finite-difference method for steady-state thermal analysis of substrate integrated waveguide filter in LTCC

A harmonic suppression band-pass filter based on symmetrical microstrip electromagnetic bandgap (EBG) structure is designed, fabricated and measured. Basic agreement between the experimental and simulation results has been achieved.

Harmonic-suppression band-pass filter with microstrip EBG

This paper presents a generalized model to investigate the wideband shielding performance of metallic rectangular cascaded enclosures with multiple rectangular apertures. The mathematical methodology is based on the integral equation technique combined with the method of moments, by which all unknown aperture fields are solved according to a set of linear algebraic equations of infinite order. Numerical computations are performed to show frequency- and geometry-dependent shielding effectiveness, especially of double- and triple-section cascaded enclosures, respectively. It is found that using metallic cascaded enclosures, high shielding performance can be achieved.

Shielding Effectiveness Characterization of Metallic Rectangular Cascaded Enclosures

An efficient compact two-dimensional (2-D) finite-difference time-domain method with weighted Laguerre polynomials (WLP-FDTD) for plastic rectangular waveguides is proposed. A typical plastic rectangular waveguide is simulated by both the 2-D WLP-FDTD method and the conventional 2-D FDTD method. Since the compact 2-D WLP-FDTD method is without the restriction of the Courant–Friedrichs–Lewy (CFL) condition, it is more efficient than the 2-D FDTD method.

Jun-Fa Mao

Papers

A 120 GHz Step-Profiled Horn Antenna in LTCC

Multilayered finite-difference method for steady-state thermal analysis of substrate integrated waveguide filter in LTCC

Harmonic-suppression band-pass filter with microstrip EBG

Shielding Effectiveness Characterization of Metallic Rectangular Cascaded Enclosures

An Efficient Compact 2-D WLP-FDTD Method for Plastic Rectangular Waveguides