Dominic Deslandes

Integrated microstrip and rectangular waveguide in planar form

Usually transitions from microstrip line to rectangular waveguide are made with three-dimensional complex mounting structures. In this paper, a new planar platform is developed in which the microstrip line and rectangular waveguide are fully integrated on the same substrate, and they are interconnected via a simple taper. Our experiments at 28 GHz show that an effective bandwidth of 12% at 20 dB return loss is obtained with an in-band insertion loss better than 0.3 dB. The new transition allows a complete integration of waveguide components on substrate with MICs and MMICs.

Single-substrate integration technique of planar circuits and waveguide filters

The integrated planar technique has been considered as a reliable candidate for low-cost mass production of millimeter-wave circuits and systems. This paper presents new concepts that allow for a complete integration of planar circuits and waveguide filters synthesized on a single substrate by means of metallized post (or via-hole) arrays. Analysis of the synthesized integrated waveguide and design criteria are presented for the post pitch and diameter. A filter design method derived from a synthesis technique using inductive post is presented. An experimental three-pole Chebyshev filter having 1-dB insertion loss and return loss better than 17 dB is demonstrated. Integrating such planar and nonplanar circuits on a substrate can significantly reduce size, weight, and cost, and greatly enhance manufacturing repeatability and reliability.

Accurate modeling, wave mechanisms, and design considerations of a substrate integrated waveguide

A new method of analysis is presented in this paper for the determination of complex propagation constants in substrate integrated waveguides (SIWs). This method makes use of the concept of surface impedance to model the rows of conducting cylinders, and the proposed model is then solved by combining a method of moments and a transverse resonance procedure. The proposed method is further applied to extract results in terms of parametric curves and graphs which demonstrate fundamental and interesting wave guidance and leakage properties of this type of periodic waveguide. Useful design rules are extracted from this analysis, suggesting that appropriate design parameters and regions should be carefully selected for practical applications. In addition, comprehensive review and comparisons with published results are also presented to show the performance and accuracy of the proposed modeling technique. Practical measurements of fabricated samples with different levels of loss have confirmed the accuracy of this new method and validity of design rules

The substrate integrated circuits - a new concept for high-frequency electronics and optoelectronics

A new generation of high-frequency integrated circuits is presented, which is called substrate integrated circuits (SICs). Current state-of-the-art of circuit design and implementation platforms based on this new concept are reviewed and discussed in detail. Different possibilities and numerous advantages of the SICs are shown for microwave, millimeter-wave and optoelectronics applications. Practical examples are illustrated with theoretical and experimental results for substrate integrated waveguide (SIW), substrate integrated slab waveguide (SISW) and substrate integrated nonradiating dielectric (SINRD) guide circuits. Future research and development trends are also discussed with reference to low-cost innovative design of millimeter-wave and optoelectronic integrated circuits.

Design Consideration and Performance Analysis of Substrate Integrated Waveguide Components

This paper presents a new design scheme and measurement results of circuit discontinuities on the basis of the recently proposed substrate integrated waveguide technology. Design considerations are discussed with respect to H-plane step, post resonator, 90° bend and 90° curvature, which are analyzed using an equivalent rectangular waveguide model. Results show a good agreement between design predictions and practical measurements. Loss properties of the discontinuities are also examined. It is demonstrated that the radiation loss of the new substrate integrated waveguide is smaller as compared to dielectric and conductor losses.

Development of substrate integrated waveguide power dividers

Two classes of substrate integrated waveguide (SIW) power divider are presented, namely, Y- and T-types. Using arrays of via, the SIW power dividers and microstrip transitions are integrated on the same substrate. Design models are presented respectively for the Y- and T-junctions. Experimental results over the Ka band are given for both structures. The Y-junction shows a bandwidth of 25.2% at -18.5 dB while the T-junction shows a bandwidth of 10.2% at -19.0 dB.

Design equations for tapered microstrip-to-Substrate Integrated Waveguide transitions

This paper presents design equations for the microstrip-to-Substrate Integrated Waveguide (SIW) transition. The transition is decomposed in two distinct parts: the microstrip taper and the microstrip-to-SIW step. Analytical equations are used for the microstrip taper. As for the step, the microstrip is modeled by an equivalent transverse electromagnetic (TEM) waveguide. An equation relating the optimum microstrip width to the SIW width is derived using a curve fitting technique. It is shown that when the step is properly sized, it provides a return loss superior to 20 dB. Three design examples are presented using different substrate permittivity and frequency bands between 18 GHz and 75 GHz. An experimental verification is also presented. The presented technique allows to design transitions covering the complete single-mode SIW bandwidth.

Integrated transition of coplanar to rectangular waveguides

Usual transitions between planar circuit and rectangular waveguide make use of 3-D complex mounting structures. Such an integration requires costly high precision mechanical alignment, In this paper, a new planar platform is developed in which a coplanar waveguide (CPW) and a rectangular waveguide are fully integrated on the same substrate, and they are interconnected via a simple transition. They can be built with a standard PCB process. Our experiments at 28 GHz show that an effective bandwidth of 7% at 15 dB return loss can easily be achieved. The CPW-to-waveguide transition allows for a complete integration of waveguide components on substrate with active components such as MMIC.

Analysis and design of current probe transition from grounded coplanar to substrate integrated rectangular waveguides

The transition between a grounded coplanar waveguide (GCPW) and a substrate integrated rectangular waveguide (SIRW) is investigated in this paper. The proposed scheme makes use of a current probe to transfer power between the two dissimilar transmission lines. A computer-aided-design-oriented analytical model is developed in order to optimize the geometrical dimensions of the transition. By using the GCPW instead of the microstrip line to interface the SIRW, substrate thickness can be increased without incurring a penalty due to transmission loss. Therefore, it is possible to achieve higher Q components. Experiments at 28 GHz show that an effective bandwidth of 10% can easily be obtained. The insertion loss is less than 0.73 dB over the bandwidth of interest.

Millimeter-wave substrate integrated waveguide filters

This paper presents the design and performance of millimeter waves filter realized with the SIW technology. Using the SIW, low-cost filter can be manufactured at millimeter-wave without tuning. A design methodology for Butterworth or Chebychev prototype is presented. Also a dual-mode filter is presented to improve the out of band rejection. An experimental inductive post Chebychev filter has been designed and measured. The 3 poles, 1 GHz bandwidth filter presents 1.1 dB insertion losses at 28 GHz and return loss better than 16.3 dB. Also, a dual mode filter has been designed and measured. The bandwidth of the 2-poles, 1-zero filter is 0.7 GHz. The insertion loss is 1.8 dB and return loss is better than 20 dB.