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

RF-MEMS Switches Designed for High-Performance Uniplanar Microwave and mm-Wave Circuits

Radio frequency microelectromechanical system (RF-MEMS) switches have demonstrated superior electrical performance (lower loss and higher isolation) compared to semiconductor-based devices to implement reconfigurable microwave and millimeter (mm)-wave circuits. In this chapter, electrostatically actuated RF-MEMS switch configurations that can be easily integrated in uniplanar circuits are presented. The design procedure and fabrication process of RF-MEMS switch topologies able to control the propagating modes of multimodal uniplanar structures (those based on a combination of coplanar waveguide (CPW), coplanar stripline (CPS), and slotline) will be described in detail. Generalized electrical (multimodal) and mechanical models will be presented and applied to the switch design and simulation. The switch-simulated results are compared to measurements, confirming the expected performances. Using an integrated RF-MEMS surface micromachining process, high-performance multimodal reconfigurable circuits, such as phase switches and filters, are developed with the proposed switch configurations. The design and optimization of these circuits are discussed and the simulated results compared to measurements

Módulo posterior del radiómetro Planck a 30 GHz: modelo de calificación

The Back End Module at 30 GHz for the Planck mission has been manufactured in its Qualification Model version. Design, integration and main performances are described. Electrical, thermal and vibration tests, already done for space qualification, are summarised. This module consists basically in four identical branches based on broadband low noise amplification, direct detection and video amplification

FULLY ADAPTABLE BAND-STOP FILTER USING VARACTOR DIODES

ABSTRACT: In this article a reconfigurable band-stop filter able to reconfigure center frequency, bandwidth, and selectivity for fine tuning applications is demonstrated, device topology discussion and implementation details are given, and followed by discussion on simulations and measurements. The reconfigurable filter topology has four poles and a quasi-elliptic band-stop filter response. The device is tuned by varactor diodes placed at different locations on the filter; varactors are voltage controlled in pairs due to filter symmetry for center 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 center frequency, which tunes filter selectivity. Simulations show a tuneable center frequency range from 1.42 to 1.48 GHz, a tuneable fractional bandwidth range from 9.46 to 12.96%, and a tuneable selectivity range from 0.53 to 0.65 dB/MHz. Measurements show a tuneable center frequency range from 1.37 to 1.43 GHz, a tuneable fractional bandwidth range from 11.31 to 15.93%, and a selectivity tuning range from 0.37 to 0.40 dB/MHz. Simulations and measurements are in good agreement