A new systematic approach for designing wideband tunable combline filters is presented. New results on tunable combline filter theory are proposed and explicit design formulas, to obtain the filter design parameters from specifications, are included. These design parameters are: center frequency, resonator electrical length, instantaneous bandwidth and tuning capacitance. The proposed design te...

This paper introduces a flexible antenna, printed on a low-cost Polyethylene Terephtalate (PET) substrate for UHF applications. The RF characteristics of the PET substrate are examined using a microstrip resonator to characterize the substrate’s relative permittivity and the loss tangent at UHF band. The PET substrate is used to print an antenna designed to work in the 868 ISMBand. The printing...

The use of quadrature RF magnetic fields has been demonstrated to be an efficient method to reduce transmit power and to increase the signal-to-noise (SNR) in magnetic resonance (MR) imaging. The goal of this project was to develop a new method using the common-mode and differential-mode (CMDM) technique for compact, planar, distributed-element quadrature transmit/receive resonators for MR sign...

A sensor that integrates high-sensitivity micro-Hall effect magnetometry and high-frequency electron paramagnetic resonance spectroscopy capabilities on a single semiconductor chip is presented. The Hall-effect magnetometer (HEM) was fabricated from a two-dimensional electron gas GaAsAlGaAs heterostructure in the form of a cross, with a 50 x 50 microm2 sensing area. A high-frequency microstrip ...

The relative permittivity of LCP material has been characterized within the whole 60 GHz frequency band using the microstrip ring resonator (MRR) method. Using a circuit model, the gap capacitance of the MRR has been taken into account in order to improve the accuracy of the determined relative permittivity. The results show that the relative permittivity of LCP is almost constant (εr ≈ 3.1) wi...

In this paper, frequency-tunable microstrip antennas, for cognitive radio applications, are proposed. The approach is based on electrically tuning the antenna’s operating frequency by integrating reconfigurable band pass filters into wideband antenna structures. The design of an open loop resonator (OLR)-based bandstop filter, and its transformation to a bandpass filter, are investigated first....

A novel microstrip lowpass filter is proposed to achieve a very wide stopband and high selectivity as well as compact size. This filter utilizes a resonator with symmetric structure that consists of a transmission line, loaded with open stubs. Each stub ends with a defected taper and these tapers are coupled two by two to generate enhanced capacitances and increase the selectivity. Two units of...

In this paper, UWB technology operating in broad frequency range of 3.1-10.6 GHz has shown great achievement for highspeed wireless communications. to satisfy the UWB system requirements, a band pass filter with a broad pass band width, low insertion loss, and high stop-band suppression. UWB band-pass filter (BPF) with wireless local area network (WLAN) notch at 5.8 GHz and 3-dB fractional band...

A retransmission chipless tag with multiple U-shaped slot resonators is proposed to cut down the cost of traditional tags chips. Multiple side-by-side structures different lengths are printed on microstrip line, and two terminals line connected correspondingly orthogonal ultra-wideband (UWB) transceiver antennas form tag. The resonator has high Q values narrow impedance bandwidth. bandwidth tha...