SummaryIn this paper, we propose a computer‐aided design (CAD) tool in the electronic design automation (EDA) domain. This tool is dedicated for the design and simulation of Radiofrequency (RF) filters that are integrated into Advanced Design System (ADS) software. It includes a graphical user interface (GUI) developed using the design kit feature available under ADS and “Application Extension Language (AEL)” as a programming language. This will extend the existing smart filter design tool under ADS by adding more types of RF filters. The proposed feature will provide to users a rapid and an accurate tool to design and simulate RF filters by presenting interactive menus facilitating the process. As a proof of concept, an application of this tool is presented for the design of a Dual‐Behavior Resonators filter. The tool can be upgraded by adding other RF components and even entire front‐end circuits. In a future step, this tool will be enhanced by adding tuning capabilities to RF filters using ideal capacitors and varactors, which will make it the first one of its kind in the literature.

A new topology for a multiband filter suitable for multistandard and multiband mobile terminals is proposed. This filter named MultiCrossed Open Stubs (MCOS) is based on the wideband Quarter-Wave Short Circuited Stubs (QWSCS) topology and consists of open stubs connected together with the main transmission line via a multicross junction. This technique allows division the wide bandpass response into several subbands by means of open stub transmission zeros. Full synthesis of the MCOS filter using ABCD matrices and its application to GSM, GPS, UMTS, LTE, and Wi-Fi standards using FR4 microstrip technology are presented. Scattering (S) parameters simulations and measurements show good agreement according to standard specifications in terms of center frequencies and bandwidths.The achievable return losses for all bands are higher than 10 dB, and transmission losses are between 3.9 dB and 6 dB.The proposed multiband filter topology is well suited for the implementation of reconfigurable multiband filters.

A novel reconfigurable dual-bandpass filter with independently controlled center frequencies and fixed bandwidths is presented. It was designed to be integrated as a radio frequency anti-aliasing filter in a reconfigurable multi-bandpass sampling global navigation satellite system (GNSS) receiver. The center frequency tuning ranges are 1190–1210 MHz and 1560–1590 MHz in the lower and the upper L-bands, respectively, with a fixed bandwidths of 35 MHz. Varactor tuning technology associated with open loop stub loaded resonator microstrip topology were investigated to achieve these goals. The proposed dual-bandpass filter design showed the agility to independently control the center frequencies in the two L-bands and to deactivate one of the passbands. Furthermore, it shows enough flexibility to adapt to the deployment of new GNSS standards specifications. It exhibits on all the tuning ranges an insertion and a return losses of less than 4.5 dB and more than 10 dB, respectively.

In this paper, we present a new specific and customized interface tool with parameter identification of Modified Butterworth-Van Dyke models for ladder bulk acoustic wave fillers. The aforementioned tool is easy to use and flexible because it allows simulations and reengineering to be conducted in an application. A modular design approach is applied to simplify the extension of the proposed tool for different topologies. The proposed tool was validated using measurements from an aluminum-nitride based ladder BAW filter dedicated to the frequency ranges of the Universal Mobile Telecommunications Service and standards and Wideband Code Division Multiple Access.

Varactor-based tunable bandpass filters are challenging solutions for next generation mobile phones that allow using one RF front-end for multiple applications. However, these solutions suffer from varactors non-linear effects that may affect signal quality and may introduce important distortions. This paper presents a thorough study of varactors nonlinear effects and some solutions for their cancellation. These solutions are applied in tunable Dual Behavior Resonator (DBR) bandpass filter to reduce non-linear distortions. S-parameter and Harmonic balance simulations were conducted to study and compare the performances of the solutions reported in the literature.

In this work, the non-linearities of a 3G/UMTS geared BandPass Bulk Acoustic Wave ladder filter composed of five resonators were modeled using non-linear modified Butterworth-Van Dyke model. The non-linear characteristics were measured and simulated, and they were compared and found to be fairly identical. The filter's central frequency is 2.12 GHz, the corresponding bandwidth is 61.55 MHz, and the quality factor is 34.55.

Global Navigation Satellite System (GNSS) receivers provide users with positioning, velocity and time. These receivers have to work with different standards and frequency bands in order to enhance the precision and the robustness. A multiband GNSS terminal with a single RF front-end would be a beneficial and cost-effective solution that allows the combination of more than two bands. The RF filter is an important component in the radio receiver. In this paper, we focus on the design of a tri-band filter operating at the three frequency bands (L5, L2, L1) of the GPS standard. The filter schematic is based on the half-wavelength bandpass topology with crossed open stubs. S parameters simulations show good agreement between the filter response and the standard specifications in terms of center frequencies and bandwidths.

In this work, we present a compact capacitively-loaded loop antenna for Ultra-High Frequency (UHF) near-field radio frequency identification (RFID) reader applications. The antenna structure is composed by folded-dipole loop structure with two C-arms and miniaturized to small size of 40 × 36 × 1.6 mm 3 for RFID applications. Our bandwidth measurement of antenna prototype is 10.5 MHz from 865-875.5 MHz with reflection coefficient less than 10 dB, which covers all of Europe RFID Band (865-868 MHz). Furthermore, a capacitive loading through two C-arms is created inside the loop antenna and has an effect of increasing the electrical length of the antenna structure. Therefore, the proposed antenna can be dedicated to different UHF RFID bands by varying the C-arm parameters. The measured reading capability of our antenna is up to 7 cm for near-field RFID Tag, and our measurements show this antenna is suitable for UHF near-field RFID reader applications.

The tunable RF filters are considered as a promising solution which can be implemented in the front-end RF of Software Defined Radio (SDR) receivers to make them suitable for multistandard wireless applications in a cost-effective and power-efficient way. In this paper, a tunable RF filter based on Dual-Behaviour Resonators (DBR) topology and excited by varactors as tuning components is presented. This filter is designed to operate in next generation transceivers using GSM, UMTS, Wi-Fi and LTE wireless standards. Special attention will be paid to the varactor model and its impact on the filter performance. S parameters simulations show a good agreement with the standards specifications in terms of center frequencies and bandwidths.

When seeking to study the performances of an RF system, the first thought that comes to mind is to measure its frequency domain response, a.k.a the S parameters. Time-domain representation could be more appropriate for numerous application, such as RADAR and complex phased array systems, which makes time-domain characterization methods more attractive and appropriate. In this paper we derive a general time-domain state space model for SMR resonators from the modified Butterworth-Van Dyke lumped equivalent model. The model is implemented under MatIab using the control systems tool box and its simulation results are validated using Advanced Design System (ADS). A resonator which series frequency is 2.05 GHz is used to demonstrate its validity. We also show that the derived model is capable of transient time domain simulation and apply it for a finite energy harmonic signal.

As an important key of Software Defined Radio (SDR) receivers, tunable filters field knows a continuous and a rapid growth to resolve some handicaps in performance like electrical specifications and physical properties, especially in weight and size. In this context, a tunable RF filter is proposed. It is based on the quarter-wave length side coupled ring topology and varactors as tuning elements. The filter is implemented on FR4 substrate. This filter covers four wireless bands: GSM, UMTS, Wi-Fi and LTE Band 7. S parameters simulations show a quite good agreement in terms of electrical specifications.

This paper present a new synthesis methodology of band pass filter used as phase shifter that allows to improve phased array system performances . This study, optimization and simulation of tunable bandpass filter centered at 2.45 GHz permit to design an efficient filter used as phase shifter based on coupled microstrip resonator loaded by varactor diodes. We have performed an electromagnetic simulation of improved 2.45 GHz RFID phased array antennas; we have implemented the synthesis methodology and we have used Momentum software to validate the obtained results. Good results were obtained in term of fractional bandwidth between 10% and 17% for our circuit and also a good dynamic range of phase shifting at operating frequency 2.45 GHz.

In this paper, a novel broadband Tag antenna for ultra-high frequency (UHF) near-field and far-field radio-frequency identification (RFID) applications is presented. This antenna is printed on an Rogers RT/duroid 5880 substrate with an overall size of 68 × 19.7 × 0.787 mm. The simulated bandwidth of the proposed Tag antenna is more than 100 MHz (860-960 MHz), which can cover the entire UHF RFID band. The proposed structure can generate a strong and uniform H-field distribution in the region around the antenna. Measurements show that the antenna operating confirms good performance of Tag identification for near-field and far-field UHF RFID applications.

The paper deals with the design of passive broadband tag antenna for Ultra-High Frequency (UHF) band. The antenna is intended for both near and far fields Radio Frequency Identification (RFID) applications. The meander dipole tag antenna geometry modification is designed for frequency bandwidth increasing. The measured bandwidth of the proposed broadband tag antenna is more than 140 MHz (820–960 MHz), which can cover the entire UHF RFID band. A comparison between chip impedance of datasheet and the measured chip impedance has been used in our simulations. The proposed progressive meandered antenna structure, with an overall size of 77 × 14 × 0.787 mm, produces strong and uniform magnetic field distribution in the near-field zone. The antenna impedance is matched to common UHF chips in market simply by tuning its capacitive and inductive values since a perfect matching is required in the antenna design in order to enhance the near and the far field communications. Measurements confirm that the designed antenna exhibits good performance of Tag identification for both near-field and far-field UHF RFID applications.

This paper reports on a new compact UWB band pass filter. Open resonator is employed and loaded with T- or L shaped open stub to achieve the UWB bandpass filter topology. The best performances filter are obtained by UWB filter based on T-open stubs compared to the other ones realized by UWB filter based on L-open stubs. 53% fractional bandwidth and 0.7dB insertion loss are gained experimentally. The proposed band-pass filter exhibiting with a wide pass-band from 5.4 to 9.4 GHz has been simulated and experimentally confirmed. The occupied size of studied filter is only 10×10 mm 2 without connectors. The experimental results show a excellent agreement with the simulation results.

In this work, RF design methodology and characterization of tunable distributed phase shifter are presented. Theoretical modeling and implementation are developed allowing an optimized design of the studied phase shifter. The new methodology allows impedance matching without additional matching network in comparison with a traditional tapered input circuit. We have realized and measured a phase shifter prototype, and good agreement is obtained between simulation and measurements confirming the good validity of our method. Thus, for the designed phase shifter prototype, the insertion loss is less than 2.0 dB and large dynamic of 100° phase was obtained at 2.4 GHz.

Reconfigurable RF filter in Software Defined Radio (SDR) receivers is a promising solution to reduce analog circuit size especially in case of multi-standard radio context. In this paper, a new approach to design tunable RF filters using dual behavior resonators (DBR) topology is proposed. This design methodology is performed to design an electrical tunable filter able to switch between UMTS, WiFi and LTE reception bands. The designed filter is simulated using FR4 microstrip technology. S parameter simulation results show good agreement with standard specifications in terms of filter center frequencies, bandwidths and selectivity.

In this paper, the T and L shaped resonators are considered for the design of UWB band pass filter which operates at the center frequency of 5 GHz. Unlike any earlier work, we propose a novel analytical performance study of T and L shaped resonators that investigates the relationship between the input admittance of both resonators and the electrical lengths. Furthermore, the simulations are carried out using Matlab® as well as ADS™ Software (Momentum). In this work, bandstop filter loaded with two T, L and mixed open stubs, are proposed to design compact UWB band pass filter. Three topology of UWB bandpass filter are presented and comparison study between the performances of these structures is made.

This b paper describes theoretical study, modeling and simulation of tunable coupled line phase shifter. This structure is based on basic Schiffman model in which a coupled dispersive microstrip transmission line was used combined with uniform transmission line. The main idea of this work is to design a mixed structure of tunable phase shifter loaded by Varactor diode. A differential phase between two paths of transmission signal was created and tuned using variable capacitance, this phase keeps approximately the same value on the operating frequency band between 0.8 and 1.4GHz. We have evaluated the performances and good variation of phase shifting was denoted with good insertion loss, less than 1.0dB and return losses for both of two signal paths.

This paper presents new study and design of microstrip phased array antennas used for extending the coverage area of RFID applications (ISO 18000-4 for 2.45GHz). The main idea is to modifying the antenna radiation pattern in order to extend the coverage area. The principle element achieving this operation is a distributed phase shifter. We have designed a patch antenna working at 2.45GHz and used it to build an antenna array. The antenna beam steering was achieved by implementing RF distributed phase shifter to excite the radiating elements of the antenna array. Distributed phase shifters are designed to provide the required phase shift to change the array pattern without disturbing the system performances.