A PARAMETRIC MODEL OF LOW-LOSS RF MEMS CAPACITIVE SWITCHES

This paper is focused on the creation of an efficient electromagnetic model of MEMS switches which operates at microwave frequencies. The switches are first characterized using a full wave analysis based on a finite element method to extract the S-parameters of the switches for different geometrical dimensions. From the S-parameter database, a scalable lumped circuit model is extracted to allow easy implementation of the switch model into commercial microwave CAD software. The lumped circuit model results are compared with published measured data as validation of our model

Magnetic/semiconductor multilayer flip-chip-type tunable bandstop filter

Abstract A flip-chip-type MMIC architecture is used to build a wideband filter with ultrathin iron (Fe) films grown on compound semiconductor substrate (GaAs). Microwave and millimeter-wave components incorporating these ferromagnetic films possess the unique capability of having a resonance frequency that can be easily tuned by an externally applied magnetic bias. A bandstop notch filter is realized using this feature, with a wide tuning range of 10-40GHz being observed with bias fields up to 5000 Oe. Measured performance is compared to simulation based on a twodimensional model employing the full permeability tensor. Introduction Present systems employing microwave and millimeterwave technology require high operating frequencies and the circuit integration of a variety of electronic components to provide wideband performance is a necessity. The maturation of ferrimagnetic microwave devices such as yttrium iron garnet (YIG)-based filters demonstrates a continuing effort to develop magnetic thin-film structures capable of operating at high frequencies The filter consists of a broadband transmission structure with a flip-chip overlay containing the magnetically active layer. The operating principle is straightforward: At the frequency of ferromagnetic resonance (FMR) electromagnetic energy is absorbed into electronic spin precession in the magnetic layer. This results in a passband outside of resonance and a sharp insertion loss peak at FMR. This notch frequency not only tunes readily with external bias but can also be combined in multiple bias configurations to yield desired stop bandwidth for microwave applications such as image frequency suppression

A 63 GHz single-feed low-profile Fabry-Pérot cavity antenna using a thick metallic FSS

A simple solution for a 63 GHz planar single-feed Fabry-Pérot cavity (FPC) antenna covered by a thick metallic frequency selective surface (FFS) is proposed. The antenna is fed through a planar feed consisting of a coplanar-waveguide-fed slot on the ground plane of the cavity. The FSS is made of periodic circular slots in a thick Brass plate. Moreover, the sides of the metallic FSS are terminated with vertical metallic walls leading to a self-supported low-profile FPC filled with air. Good agreement is observed between measured and simulated results. © 2013 IEEE

A 44 GHz single-Feed Fabry-Pérot Cavity antenna designed and fabricated on quartz

In this paper, a design of Fabry-Pérot Cavity antenna at millimiter-waves frequencies is investigated. Four Fabry-Pérot cavity antennas, covered by different Frequency Selective Surfaces, are discussed which are fabricated on a Quartz disk to guarantee mechanical stability and also for ease of fabrication, probing and measurement. A planar feed, a slot dipole fed by a coplanar waveguide, is also designed to excite the cavities. Prototypes have been designed and fabricated at central frequencies in frequency range of 42 to 46 GHz with various gains; however the same design can be adopted at higher frequencies. Full-wave simulations, done by Ansys HFSS, are verified with measurement results. © 2011 IEEE

Design of a single-feed 60 GHz planar metallic Fabry-Perot cavity antenna with 20 dB gain

In this paper a Fabry-Perot cavity (FPC) has been used to design a 60 GHz single feed directive antenna. The FPC antenna is made by a ground plane covered by a frequency selective surface (FSS). We have provided simple design guidelines based on a transmission line model. Numerical simulations confirm the design guidelines and antenna performances. ©2009 IEEE

Single-feed highly-directive Fabry-Perot Cavity antenna for 60 GHz wireless systems: Design and fabrication

In this paper, a prototype Fabry-Perot Cavity (FPC) antenna is designed and fabricated at millimeter-wave frequencies, aiming at designing directive antennas for 60 GHz wireless systems. A prototype FPC antenna is designed to have 17 dB gain at 42.8 GHz with 600-700 MHz 3dB-pattern-bandwidth and it is designed in order to be mounted on a wafer (chip). Measurement tools at millimeter frequencies and also antenna integration possibilities lead us to design an efficient feeding network for this kind of antenna. The antenna is fabricated on a quartz wafer (very low loss dielectric especially at millimeter-wave frequencies) which is coated by a thin layer of gold on each side. All the simulations on the reflection coefficient, gain and the radiation pattern of the antenna are done and compared using two most powerful EM simulators, Ansoft HFSS and Zeland IE3D and they are also compared with some measurement results for the prototype antenna. © 2010 IEEE

Design of a single-feed all-metal 63 GHz Fabry-Perot cavity antenna using a TL and a wideband circuit model

In this paper, we show a wideband transmission line (TL) model for a Fabry-Perot cavity (FPC) antenna which is designed at a center frequency of 63 GHz using a thick and slotted metallic partially reflective surface. Then, by using the proposed wideband circuit model, we predict the gain and 3dB gain bandwidth of the antenna, assumed as infinitely large in the transverse domain (for the modeling purposes). Finally we compared the circuit model results to the full-wave ones for a FPC antenna of finite extent. © 2009 IEEE

A highly-efficient single-feed planar Fabry-Pérot cavity antenna for 60 GHz technology

A low-loss planar Fabry-Pérot cavity antenna fed by a planar feed, a CPW-fed slot dipole, is designed and fabricated for 60 GHz wireless systems. The antenna is fabricated on a planar substrate using standard lithography process. The measurement results of the fabricated antenna are in good agreement with simulation data and show a gain of 16.5 dB. © 2012 IEEE

Design of a single-feed 60 GHz planar metallic Fabry-Perot cavity antenna with 20 dB gain

In this paper a Fabry-Perot cavity (FPC) has been used to design a 60 GHz single feed directive antenna. The FPC antenna is made by a ground plane covered by a frequency selective surface (FSS). We have provided simple design guidelines based on a transmission line model. Numerical simulations confirm the design guidelines and antenna performances. ©2009 IEEE

Design of a single-feed all-metal 63 GHz Fabry-Perot cavity antenna using a TL and a wideband circuit model

In this paper, we show a wideband transmission line (TL) model for a Fabry-Perot cavity (FPC) antenna which is designed at a center frequency of 63 GHz using a thick and slotted metallic partially reflective surface. Then, by using the proposed wideband circuit model, we predict the gain and 3dB gain bandwidth of the antenna, assumed as infinitely large in the transverse domain (for the modeling purposes). Finally we compared the circuit model results to the full-wave ones for a FPC antenna of finite extent. © 2009 IEEE