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A non-uniform C-section phaser is introduced as a powerful approach to enhance the design flexibility of uniform phasers. Moreover, an efficient synthesis technique is provided to design such phasers. Two design examples are presented. The first example is a single non-uniform C-section phaser. The second one is a cascaded double non-uniform C-section phaser featuring larger group delay swing and...
A nonuniform symmetrical QTEM-mode directional slot-line coupler operating in a multi-octave frequency range from 2.5 GHz up to 28.6GHz is presented. The calculated continuously varying even- and odd-mode line impedances are realized by a 3D electromagnetic (EM) field simulation of the slot-coupled microstrip cross section. A new method of even- and odd-mode phase velocity compensation, based on a...
An on-chip miniaturized 3-dB directional coupler is investigated in this paper using coupled synthesized coplanar waveguides (CPWs) on the integrated passive device (IPD) process. Coupled spiral inductors and MIM capacitors are used to achieve tight coupling between the lines. The proposed on-chip coupler is only 15% the length of a conventional design in CPW form on the same substrate. The design...
High directivity is achieved in a 3 dB directional coupler operating over the 6–18 GHz range. A symmetric, tri-sectional microstrip structure is employed with tight and weak coupling at the center and adjacent sections, respectively. To enhance directivity and return loss in the weak coupling sections, a new design methodology is used, based on manipulating the gap and metal lines such that even and...
In this paper broadband branch-line couplers with loose couplings (less than −10 dB) utilizing open/short-circuited coupled-transmission lines are proposed. By applying the equivalent admittance approach to the proposed branch-line coupler, broadband characteristics with a relative bandwidth of 47.5% for 20 dB return loss and directivity can be obtained in the case of the branch-line coupler with...
An original solution for the realization of pseudoelliptic evanescent mode filters with extreme close-in rejection is presented in this paper. The basic idea consists of using high-Q bypassed TE201 mode cavities embedded within two or more evanescent mode resonators. Such a combination of resonators allows the generation of extremely close transmission zeros while realizing at the same time relatively...
This paper presents a novel filter topology for the implementation of asymmetric responses with transmission zeros (TZs) in rectangular waveguide technology. It is based on a compact folded E-plane arrangement where adjacent resonators are capacitively coupled through rectangular slots, and non-adjacent resonators are coupled through simple inductive windows. The new folded configuration allows the...
In this paper, an original solution for dielectric wide bandpass filters is introduced. A 4-pole filter based on the TM01δ mode has been designed in a single piece including resonators and coupling elements. The dielectric part is based on a high permittivity material (Zirconia) and has been manufactured using additive manufacturing technology (stereolithography). The breadboard shows a Q-factor around...
A 12×12 Switch Matrix Unit featuring silicon RF MEMS assembled on LTCC boards has been developed under a Contract with the European Space Agency (ESA) for satellite communication application. The Switch Matrix is a complete Engineering Model unit, housed in a mechanical box in aluminum with RF coaxial connectors and DC connectors for powering and commanding. To the authors' knowledge, it is the first...
Vialess shielded composite right/left-handed (CRLH) stripline is proposed. The structure preserves the CRLH properties while preventing undesired radiations and minimizing electromagnetic interference (EMI) coupling from the surrounding noisy environments. The vialess topology also allows a simple realization option. As an application example, a 3-dB directional coupler and a novel broadband tunable...
This paper presents a novel type of tunable band-pass filters with constant bandwidth and wide tuning range. A constant absolute pass-band has been obtained by integrating a low-pass filter at the input and the output of the filter. The filter fabricated on duroid substrate can be tuned from 690MHz up to 1130MHz, by using RF-MEMS switches mounted in series with fixed capacitors. Matching is better...
This paper introduces a new concept capable of obtaining a wide frequency excursion, keeping high electrical performances. To reach such performances, the use of waveguide resonators is chosen, actuated by a mechanical system is made. Starting from a classical 2 pole E-plane filter, which consists of thin walls implemented along the propagation axis inside a waveguide, we make both the filter external...
We report on a resonantly-coupled wireless power (RWPT) system for locomotion of a seat in an automobile environment. The seat moves transversely 28 cm, resulting in a time-varying geometry and coupling. In addition, the proximity of a metallic undercarriage creates the potential for interference and additional loss. We present a system that was able to achieve 80% efficiency over the entire 28 cm...
Backward-wave oscillation is frequently a problem in TWT amplifiers that use the conventional circular helix slow-wave structure (SWS). Circular contra-wound helix SWS, proposed in the past to solve this problem, is hard to fabricate at high frequencies. In this paper, we propose a planar contra-wound planar helix SWS with potential for microfabrication. It is shown with the help of simulated dispersion...
In this article the design and the construction of an ultrawideband (UWB) 3 dB hybrid coupler are presented. The coupler is realized in broadside stripline technology to cover the operating bandwidth 0.5 – 18 GHz (more than five octaves). Detailed electromagnetic design has been carried to optimize performances according to bandwidth. The comparison between simulations and measurements validated the...
First imaging tests of a 4-channel RF coil using novel 41 cm-long dipole elements with an eigen-resonant shielding plate in a 7-Tesla magnetic resonance imaging (MRI) system are presented. The proposed 4-channel coil is loaded by a homogeneous phantom to model the human body. Gradient echo images on the transverse, sagittal and coronal planes are acquired in CP+ mode and compared to the more established...
This paper presents a new coupling matrix synthesis method. The method synthesizes a coupling matrix by moving poles and zeros to their own target positions in the complex plane. Mathematically speaking, the procedure is to solve a system of nonlinear equations using Newton's method. In addition, a new algorithm for generating the initial values is devised. The method exhibits a lower possibility...
An effective coupling topology for multi-phase oscillators is proposed and demonstrated in a standard 90nm CMOS technology. Compared with the conventional parallel or series coupling methods, the PMOS-source-follower coupled (PSFC) technique with the coupling transistors operated in the cut-off region can significantly reduce the flicker noise and hence the phase noise of VCO. The proposed PSFC QVCOs...
We discuss in this work a novel approach to the synthesis of dual-band filters having a parallel-connected topology. The only existing synthesis technique for this class of filters offers a very limited control over the topology of the two constituting filters. The approach we propose allows to control the number of transmission zeros of each filter connected in parallel, making the realization of...
Many authors have published methods to synthesize microwave filters that provide a circuit prototype composed of ideal resonators and ideal couplings between them. Usually, the implementation step of that network with a particular technology is provided with few details. This work presents a method to synthesize a rectangular waveguide filter with transmission zeros designed by the extracted pole...
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