Dual-band filtering power divider with capacitor-loaded centrally coupled-line resonators

In this paper, a dual-band filtering power divider (DB-FPD) with capacitor-loaded centrally coupled-line resonators (CLCCLRs) is presented. The proposed design utilizes four CLCCLRs, two resistors and one inductor to achieve the dual functions of dual-band filtering and power division. By altering the values of the capacitors loaded at the ends of the coupled-lines, the center frequencies of the two passbands can be adjusted independently. It is noted that changing one passband will not affect the other. For demonstration, a microstrip filtering power divider is designed, fabricated and measured. Under different values of the loaded capacitors, experimental results show that the lower band center frequency varies from 0.7 GHz to 1.0 GHz with the upper band fixed at 1.75 GHz, whereas the upper band center frequency varies from 1.65 GHz to 1.95 GHz when the lower band is fixed at 1.0 GHz. The measured results show good agreement with the simulations

Wideband bandpass-to-all-stop reconfigurable filtering power divider with bandwidth control and all-passband isolation

A novel wideband bandpass-to-all-stop reconfigurable filtering power divider is proposed in this study, which allows for four-order bandpass-to-all-stop reconfigurable operating function and equal power division. Its circuit configuration includes the cascaded coupled-line sections with tight coupling to extend the impedance transforming. Furthermore, with the introduction of the half-wavelength open-circuit stubs, which controls the bandwidth, extra transmission poles located at the cut-off frequency are generated, thus resulting in high frequency selectivity. Moreover, by using a single resistor between input coupled-lines, the high all-passband isolation can be achieved. The grounding are then loaded to the output coupled-lines to enable bandpass-to-all-stop operating functionality. For demonstration, a prototype operating at 2 GHz is designed, simulated, and measured with a 15 dB bandwidth of 51%, 19 dB stopband rejection up to 5 GHz, and 14.5 dB all-passband isolation, which shows a good agreement between the simulated and measured results

A Horst-type Power Divider with Wide Frequency Tuning Range Using Varactors

OAPA This paper presents a novel power divider with a wide frequency tuning range. In our previous work, a pair of capacitors were connected in parallel with the front transmission lines of a Trantanella-type power divider introducing an additional reflection minimum together with the original reflection zero to broaden the bandwidth. In this design, the latter transmission lines are removed. The added capacitors generate a reflection minimum which can be easily controlled by varactors. Thus, the frequency band of the power divider can be flexibly tuned by altering the varactors. Design parameters are carefully chosen to eliminate the effect of the original reflection zero. By doing so, the power divider will have a tunable centre frequency instead of a tunable bandwidth. Theoretical formulas for the characteristic impedances and electrical lengths of the transmission lines of the power divider are derived and analyzed. A power divider has been designed and fabricated to demonstrate the validity of the proposed design. The measured results indicate that the power divider can achieve a frequency tuning range of 0.9-4.2 GHz (fH/fL= 4.67:1), with in-band input and output return losses both better than 22 dB, and an insertion loss of 3.2-4 dB. The measured in-band isolation is better than 15 dB. The power divider has a simple layout and a compact size of 0.2 Ωg ෗ 0.16 Ωg which demonstrates the excellent potential of the proposed power divider for modern communication systems

A Survey of Differential-Fed Microstrip Bandpass Filters: Recent Techniques and Challenges

Differentially driven devices represent a highly promising research field for radio frequency (RF), microwave (MW), and millimeter-wave (mmWave) designers and engineers. Designs employing differential signals are essential elements in low-noise fourth-generation (4G) and fifth-generation (5G) communications. Apart from the conventional planar MW components, differential–fed balanced microstrip filters, as promising alternatives, have several advantages, including high common-mode rejection, low unwanted radiation levels, high noise immunity, and wideband harmonic suppression. In this paper, a comprehensive and in-depth review of the existing research on differential-fed microstrip filter designs are presented and discussed with a focus on recent advances in this research and the challenges facing the researchers. A comparison between different design techniques is presented and discussed in detail to provide the researchers with the advantages and disadvantages of each technique that could be of interest to a specific application. Challenges and future developments of balanced microstrip bandpass filters (BPFs) are also presented in this paper. Balanced filters surveyed include recent single-, dual-, tri-, and wide-band BPFs, which employ different design techniques and accomplish different performances for current and future wireless applications

Unbalanced two-way filtering power splitter for wireless communication systems

A compact unbalanced two-way filtering power splitter with an integrated Chebyshev filtering function is presented. The design is purely based on formulations, thereby eliminating the constant need for developing complex optimization algorithms and tuning, to deliver the desired amount of power at each of the two output ports. To achieve miniaturization, a common square open-loop resonator (SOLR) is used to distribute energy between the two integrated channel filters. In addition to distributing energy, the common resonator also contributes one pole to each integrated channel filter, hence, reducing the number of individual resonating elements used in achieving the inte-grated filtering power splitter (FPS). To demonstrate the proposed design technique, a prototype FPS centered at 2.6 GHz with a 3 dB fractional bandwidth of 3% is designed and simulated. The circuit model and layout results show good performances of high selectivity, less than 1.7 dB insertion loss, and better than 16 dB in-band return loss. The common microstrip SOLR and the microstrip hair-pin resonators used in implementing the proposed integrated FPS ensures that an overall compact size of 0.34 λg × 0.11 λg was achieved, where λg is the guided-wavelength of the 50 Ω microstrip line at the fundamental resonant frequency of the FPS passband

Control and evaluation of the ad-fmcomms5-ebz software-defined radio

Software-defined radios (SDR) have presented a new way to do telecommunication systems in a configurable, efficient and portable manner. With the rapid evolving capabilities of these systems, the traditional non-software-configurable ones are being left behind. This project explores the concept of software-defined radio in a theoretical and practical way using the ADFMComms5-EBZ, a SDR provided by Analog Devices with 4 transceivers. A complete analysis is done on the AD-FMComms5-EBZ, understanding all its physical components and its digital interface that make it software-configurable. Furthemore, its interaction with MATLAB/Simulink and with the IIO Oscilloscope application is studied, providing a profound explanation of the board's capabilities on these software. Finally, a few algorithms we found interesting are designed with MATLAB to enable all the potential of the board by reaching MIMO capabilities, analysing the phase of each transmitter and the reception order of symbols.Les ràdios definides per software (SDR) s'han presentat com a una nova manera de fer sistemes de telecomunicacions gràcies a la seva configurabilitat, eficiència i portabilitat. La seva evolució ha sigut ràpida i contínua, fent que els sistemes tradicionals que no son configurables en software s'hagin quedat enrere. Aquest projecte explora el concepte de ràdio definida per software de forma teòrica i pràctica utilitzant l'AD-FMComms5-EBZ, una SDR dissenyada per Analog Devices que incorpora 4 transceptors. En el projecte s'hi fa una anàlisi completa de l'AD-FMComms5-EBZ, entenent tots els seus components físics i la seva interfície digital que en permet la configurabilitat per via de software dels seus components. A més, s'estudia la seva interacció amb MATLAB/Simulink i amb l'aplicació IIO Oscilloscope, donant una explicació profusa de les capacitats de la placa amb aquest programari. Finalment, es dissenyen alguns algoritmes que hem trobat interessants amb MATLAB per a habilitar tot el potencial de la placa, aconseguint que funcioni com a un sistema MIMO, analitzant la fase ens els diferents transmissors i l'ordre de la recepció dels símbols.Las radios definidas por software (SDR) se han presentado como una nueva manera de hacer sistemas de telecomunicaciones gracias a su configurabilidad, eficiencia y portabilidad. Su evolución ha sido rápida y continua, haciendo que los sistemas tradicionales que no son configurables en software se hayan quedado atrás. Este proyecto explora el concepto de radio definida por software de forma teórica y práctica utilizando el AD-FMComms5-EBZ, una SDR diseñada por Analog Devices que incorpora 4 transceptores. En el proyecto se hace un análisis completo de la AD-FMComms5-EBZ, entendiendo todos sus componentes físicos y su interfaz digital que permite su configurabilidad por vía de software de sus componentes. Además, se estudia su interacción con MATLAB / Simulink y con la aplicación IIO Oscilloscope, dando una explicación profusa de las capacidades de la placa con este software. Finalmente, se diseñan algunos algoritmos que hemos encontrado interesantes con MATLAB para habilitar todo el potencial de la placa, consiguiendo que funcione como un sistema MIMO, analizando la fase en los diferentes transmisores y el orden de la recepción de los símbolos