Presents an efficient numerical application of the Galerkin method in the spectral domain (SD) to the analysis of striplike/slotlike coplanar transmission lines embedded in a bianisotropic multilayered medium. The method is based on obtaining the spectral dyadic Green's function by the equivalent boundary method (EBM), a suitable third order extraction technique of the asymptotic behavior of the Green's dyad, an enhanced numerical integration scheme, and the use of an adequate contour integral method for searching zeros in the complex plane. This method, namely the SD-EBM, has been found to be very suitable for analyzing transmission lines with semiconductors and/or ferrites magnetized at an arbitrary direction, including the study of magnetostatic wave propagation phenomena. >

An efficient numerical spectral domain method to analyze a large class of nonreciprocal planar transmission lines

A phase shifting structure that exhibits both broadband operation and high nonreciprocity is presented. This structure comprises a slot line between two oppositely magnetized ferrite substrates. A full-wave spectral-domain analysis is used, where Green's functions are formulated using a transmission matrix approach. By eliminating the use of relatively thick high-dielectric substrates, a bandwidth of 3:1 and a differential phase of 50 degrees /cm are feasible. The geometry of the present structure can be optimized to increase both the nonreciprocity and the bandwidth. The characteristic impedance of the slot line is presented and shows a strong dependence on the slot width and the state of ferrite magnetization. The addition of thin layers of high-dielectric material increases the differential phase to over 100 degrees /cm without significantly reducing the bandwidth. These layers were found to reduce the variation of characteristic impedance versus the ferrite magnetization. >

Dual-ferrite slot line for broadband, high-nonreciprocity phase shifters

A general theory for analysing an inclined microstrip-slotline transition is proposed, with a view to developing a network model of the transition The reciprocity theorem and spectral-domain immittance approach are invoked to formulate the electromagnetic field analysis The equivalent circuit model consists of an ideal transformer and a series reactance element, and the circuit element parameters are explicitly expressed The theory is applied to some examples of the transition, including a feed for the tapered-slot antenna, and is shown to yield more accurate results than previous theories

Network analysis of inclined microstrip-slotline transitions

During the past decade, several new fabrication techniques have evolved which helped popularize micro-electromechanical systems (MEMS), and numerous novel devices have been reported in diverse areas of engineering and science. One such area is microwave and millimeter wave systems. MEMS technology for microwave applications should solve many intriguing problems of high frequency technology for wireless communications. The recent and dramatic developments of personal communication devices forced the market to acquire miniaturized efficient devices, which is possible only by the development of RF MEMS. Semiconductor- polymer based sensor use silicon use silicon or compound semiconductors as inorganic parts with sensitive polymers as insulating, semiconducting or conductive materials. Organic thin film transistor has also been fabricated using this concept. These devices may allow control circuitry to be integrated with 2D or 3D MEMS. Interdigital type RF-MEMS can be designed and fabricated with Interdigital Electrodes (IDE) deposited on either polymer or an inorganic material such as Barium Strontium Titanate (BST). In the case of polymer-based device, we study the capacitance change and calibrate it for desired sensing application. In the inorganic case, we make use of the change in dielectric properties of BST as a function of DC bias. IDE will act like a RF filter and oscillator just like the comb-type RF MEMS devices. These polymeric based devices can be integrated with organic thin film transistors. RF switches, tuners and filters are some of the initial applications of RF MEMS although many others are still under development. In this paper we present the design and development of few devices such as phase shifters, switches and IDT capacitors. It is observed that, dielectric constant of BST thin film changes by more than 50 percent with an applied bias voltage of 25 V dc, which could therefore be easily implemented in RF switch.

Semiconductor polymer-based rf MEMS and its applications to microwave systems

New types of planar transmission lines employing multilayer structures are proposed for possible applications in microwave and millimeter-wave integrated circuits. Detailed investigations are presented through numerical results calculated using the spectral domain technique. The newly proposed transmission lines have many attractive features such as a large impedance range, flexibility and ability to realize complicated, densely packed integrated circuits, as well as miniaturization through the use of thin dielectric layers. Additionally, they possess all of the inherent advantages of the CPW and microstrip line. Their use in microwave circuits is exemplified through a low-pass filter realized using the new slot-coplanar lines with less than 0.5-dB insertion loss and better than 20-dB return loss. The filter's measured and calculated performances also agree well. >

New multilayer planar transmission lines for microwave and millimeter-wave integrated circuits

The analysis and design of printed phase shifters based on the microstrip line are described. A spectral-domain analysis is presented where the necessary Green's functions are formulated using the transmission matrix technique. The nonreciprocal characteristics for single-layer and multilayer structures are studied. Microstrip-slot in a multilayer structure of ferrite and high-dielectric material is found to have considerably more nonreciprocity than microstrip-slot for microstrip in a single-layer structure. Over 65 degrees /cm is predicted for certain optimized designs. This, in addition to the 50- Omega design capability of the line, makes the microstrip-slot line a suitable choice for phase shifting applications. A multilayer microstrip-slot line was constructed on a rectangular ferrite toroid. Differential phase shifts of roughly 45 degrees /cm were measured over a 6.0-8.5-GHz frequency range. These results are in good agreement with the analysis. >

E.-B. El-Sharawy

Papers

Analysis and design of microstrip-slot line for phase shifting applications