Microfabricated Otto chip device for surface plasmon resonance based optical sensing

Surface plasmon resonance (SPR) based sensors are usually designed using the Kretschmann prism coupling configuration in which an input beam couples with a surface plasmon through a thin metal film. This is generally preferred by sensor developers for building planar devices instead of the Otto prism coupling configuration, which, for efficient coupling, requires the metal surface to be maintained at a distance on the order of the wavelength from the input prism surface. In this paper, we report on the microfabrication and characterization of an Otto chip device, which is suitable for applications of the SPR effect in gas sensing and biosensing

Sintonización automática de filtros de microondas mediante motores a pasos

Este artículo describe un sistema para sintonizar filtros de microondas de manera automática. Se presentan los resultados obtenidos de la sintonización automática de un resonador de microondas mediante un sistema diseñado específicamente para tal propósito. Este sistema es extrapolable a filtros de microondas que requieren múltiples tornillos de sintonización. El sistema diseñado se encarga de pedir al usuario los datos necesarios, procesar las medidas realizadas y finalmente hacer girar un motor a pasos para conseguir el ajuste deseado de frecuencia de resonancia. El tornillo de sintonización está unido al motor a pasos, y al girar el motor se hace variar la frecuencia del resonador. Dependiendo del paso del motor se podrá conseguir mayor precisión en el ajuste, pero lo que se mejora sustancialmente es el tiempo invertido en la sintonía y la velocidad a la que se puede cambiar la respuesta del dispositivo.Peer Reviewe

All resonator based LTCC diplexer using substrate integrated waveguides

A compact diplexer is implemented in Low-Temperature-Cofired-Ceramic (LTCC) technology and consists of six coupled Substrate-Integrated-Waveguide (SIW) cavity resonators stacked in two layers. No transmission-line based junction is used. The couplings between the cavities are achieved through both SIW irises and slots placed in metal layers. The diplexer has two third-order filtering channels, centred at 2.7 and 3.3 GHz with 120 MHz bandwidths. The overall size of the diplexer is 27.74 mm (2.3 λg at 3 GHz) × 10.4 mm (0.86 λg at 3 GHz) × 0.84 mm, achieved by using an LTCC material of a high dielectric constant of 68. Simulations and measurements are in good agreement to demonstrate a compact diplexer based on an all resonator structure using high dielectric constant LTCC material

Review on Microwave and Millimeter Filters Using MEMS Technology

Abstrac

Characterizing a Tune-all bandstop filter

In this paper a reconfigurable bandstop filter able to reconfigure central frequency, bandwidth and selectivity for fine tuning applications is presented. The reconfigurable filter topology has four poles and a quasielliptic bandstop filter response. The filter is tuned by varactor diodes placed at different locations on the filter topology. The varactors are voltage controlled in pairs due to filter symmetry for central frequency and bandwidth control. An additional varactor is placed on a crossing line to move a pair of transmission zeros, closer or farther to the filter central frequency, which tunes filter selectivity. The filter has a tuneable fractional bandwidth range from 11.51 to 15.46%, a tuneable central frequency range from 1.346 to 1.420 GHz and a selectivity tuning range from 0.37 to 0.40 dB/MHz.Postprint (published version

Filtros para un cabezal de comunicaciones entre vehículos

In this paper two reconfigurable bandpass filters able to switch between WiFi and UMTS for transmit and receive band standards are presented. The filters are designed in such a way that center frequency and bandwidth specifications are precisely met by defining two switchable filter topologies. Design specifications require two center frequency states, one at 2.440 GHz with an 80 MHz bandwidth and a second center frequency state at 1.955 GHz with a 140 MHz bandwidth for the WiFi and UMTS transmit bands. The second filter is able to have one center frequency at 2.440 GHz with an 80 MHz bandwidth and a second center frequency state at 2.165 GHz with a 110 MHz bandwidth for the WiFi and UMTS receive bands, respectively. Filter simulations were performed to match the required filters specifications. Measured results on the transmit filter show a very good agreement with the simulations where a 2.428 GHz center frequency with a 71 MHz bandwidth was obtained for the WiFi state, and a 1.939 GHz center frequency with a 144 MHz bandwidth was obtained for the UMTS filter state. Simulated results on the receive filter show a very good agreement with the specified parameters. The filters specifications were successfully matched with the proposed filter topologies.Postprint (published version

Inkjet-Printed Silver CPW with Narrow Gap

Inkjet-printed silver coplanar waveguide on a glass substrate with narrow gap is firstly realized by using a selective surface treatment. The measured gap between signal and ground is 16.7 mm. Insertion loss is measured to be 2.04 dB/cm and 4.40 dB/cm at 10 GHz and 40 GHz, respectively

Frequency and Bandwidth Control of Switchable Microstrip Bandpass Filters using RF-MEMS Ohmic Switches

Abstract -In this paper a reconfigurable bandpass filter is designed using ohmic-contact cantilever-type Micro Electro Mechanical Systems (MEMS) switches. The filter can switch between two different states with a center frequency tunable range of 13% in C band. The topology allows achieving two accurate center frequencies, each associated with a precisely defined bandwidth, using six MEMS ohmic-switches. The design carefully takes into account the external quality factor for both filter states to ensure a good impedance match at each frequency. The two sets of coupling coefficients and resonator lengths implemented with the MEMS ohmic switches originate the bandwidths and center frequencies required by design specifications. The filter is designed to have center frequencies of 5.5 and 6.2 GHz, with a fractional bandwidth (FBW) of 5 and 3%, respectively. Filter specifications were successfully met with the proposed topology. The filter was fabricated on a quartz substrate and measured responses are in good agreement with simulations