John Papapolymerou

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Liquid crystal polymer (LCP) is a material that has gained attention as a potential high-performance microwave substrate and packaging material. This investigation uses several methods to determine the electrical properties of LCP for millimeter-wave frequencies. Microstrip ring resonators and cavity resonators are measured in order to characterize the(More)
This paper investigates both theoretically and experimentally the dielectric charging effects of capacitive RF microelectromechanical system switches with silicon nitride as dielectric layer. Dielectric charging caused by charge injection under voltage stress was observed. The amphoteric nature of traps and its effect on the switch operation were confirmed(More)
A planar Microwave Band Gap (MBG) cavity resonator filter that is completely compatible with current commercial printed circuit board (PCB) fabrication techniques has been designed, fabricated and tested. This filter provides a 1.33% bandwidth passband response at 10.67 GHz with a corresponding insertion loss of 2.17 dB. Design considerations and equations(More)
This paper presents novel planar dynamically reconfigurable double-stub tuners that utilize electrostatically activated microelectromechanical system (MEMS) switches. The tuners operate in the 10–20-GHz frequency range and have stubs that consist of a digital capacitor bank. Each bank has a predetermined number of capacitors that can be selected through the(More)
In this paper, microstrip coupled-line bandpass filters using a Koch fractal shape are proposed for the first time. These filters are fabricated on a liquid crystal polymer (LCP) substrate for Ku-band. Conventional microstrip coupled-line filters are very popular for RF front ends because they can be fabricated easily. However, their large second harmonic(More)
A standard non-metallized liquid crystal polymer (LCP) 4 mil thick microwave substrate with depthcontrolled laser-micromachined cavities was investigated as a system-level packaging layer for integrated packaging of monolithic microwave integrated circuits (MMICs) and radio frequency microelectromechanical systems (RF MEMS) switches. The RF characteristics(More)
A reconfigurable planar electromagnetic bandgap (EBG) cavity resonator has been designed, fabricated, and tested. The resonator, based on a microstrip-coupled cavity constructed with periodic metallic post side walls, resonates at 10.60 GHz or 8.63 GHz, depending on the state of two rows of switchable post elements. Fabricated on 0.031” 5880 Duroid, the(More)
Modern RF-MEMS device design is difficult due to the lack of tools capable of simulating highly integrated structures. This paper presents methods in which the FDTD technique can be used to model a reconfigurable RF-MEMS tuner. A new method of modeling a conductor intersecting a cell is presented. In addition, code parallelization and variable gridding are(More)
This paper presents the design and measured performance of an X-band to Ka-band SiGe HBT SPDT switch. The proposed SPDT switch was fabricated using a 200 nm, 150 GHz peak f<sub>T</sub> silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) BiCMOS technology. The SPDT switch design uses diode-connected SiGe HBTs in a series-shunt configuration to(More)