Power Division Ratio Research Articles

A Fully Integrated Arbitrary Power Divider on Printed Circuit Board by a Novel SMD-Resistor-Free Isolation Network

An arbitrary power divider (PD), which can be fully integrated on a multilayered printed circuit board (PCB), is presented without using the surface-mounted device (SMD) resistors. In the proposed SMD-resistor-free isolation network, a new multiple microstrip gap-coupled resonators (MM-GCRs) is designed in an FR4 substrate based on an optimization algorithm to achieve an equivalent grounded resistor in the desired frequency band. Consequently, the acquired output matching and isolation bandwidths are designable and much wider than that of other existing SMD-resistor-free PDs with both output matching and isolation characteristics. To verify it, the design of PCB-based SMD-resistor-free PDs with the power division ratio being 1–3 is given. For all fabricated PDs, the measured input return loss and extra insertion loss are, respectively, better than 20 dB and less than 0.52 dB, respectively, at the operating frequency. In addition, the measured output return loss and isolation loss are better than 15 dB from 2.4 to 2.5 GHz. Moreover, the measured output matching and isolation bandwidths are, respectively, 8 and 3.5 times wider than that of other existing SMD-resistor-free PD with both output matching and isolation characteristics. Since the proposed PD is synthesized based on distributed elements without using any SMD resistor, the proposed PD thus possesses the advantages of being suitable for system-on-package (SoP), cost-efficient, suitable for millimeter-wave (mm-Wave) application, and capable to be fully integrated on a multilayered PCB.

Planar Reconfigurable Balanced Rat-Race Coupler With Improved Amplitude Imbalance Performance and Common-Mode Noise Absorption

In this article, the design method for absorptive balanced rat-race couplers with reconfigurable power-dividing ratio is proposed for the first time. First, the differential-mode (DM) and common-mode (CM) port equivalent impedances of the eight-port balanced network is derived by the even–odd mode method under the mixed-mode isolation and matching conditions. The power-dividing ratio is tuned by changing the admittance ratio of the network components, which greatly extends the amplitude imbalance bandwidth. Then, a nonabsorptive reconfigurable balanced rat-race coupler that consists of transmission lines with adjustable characteristic impedance is proposed. Furthermore, based on the derived DM and CM port equivalent impedances, an absorptive network is designed. Finally, the absorptive reconfigurable balanced rat-race coupler is achieved by attaching the absorptive network at the balanced ports of the designed nonabsorptive reconfigurable balanced rat-race coupler. For verification, the 2-GHz nonabsorptive and absorptive reconfigurable balanced rat-race couplers are designed and measured. The measured results agree well with the simulations. For the nonabsorptive coupler, the measured power-dividing ratio is tuned from −8.5 to 8.9 dB, while the 15-dB DM matching and isolation bandwidth is greater than 370 MHz. For the absorptive coupler, the measured power-dividing ratio is tuned from −8.3 to 9.0 dB, while the 15-dB DM matching and isolation bandwidth and 15-dB CM matching bandwidth are greater than 450 and 1150 MHz, respectively. The measured 0.5-dB amplitude imbalance bandwidths of the nonabsorptive and absorptive couplers are 6%–14.5% and 7%–15.6%, respectively.

An unequal power divider based on ridge gap waveguide with an inserted conductor plate

AbstractA novel unequal power divider based on ridge gap waveguide is proposed and investigated in this paper. The half‐height pin gap waveguide structure is applied to acquire the required stopband. The whole divider can be divided into three parts. The first part is the core of the divider which is a gap waveguide transmission line with a thin inserted conductor plate (ICP). The ICP is printed on a thin substrate for the mechanical feasibility and stability. The position of the ICP can be changed to adjust the power division ratio (PDR). The ICP separates the divider into two different layers. Then, the second and third parts are transitions from top layer and bottom layer to normal gap waveguide transmission lines. Two power dividers with different PDRs of 1:2 and 1:4 working at 28 GHz are designed and manufactured to verify this topology.

Principles, fundamentals, and applications of programmable integrated photonics

Programmable integrated photonics is an emerging new paradigm that aims at designing common integrated optical hardware resource configurations, capable of implementing an unconstrained variety of functionalities by suitable programming, following a parallel but not identical path to that of integrated electronics in the past two decades of the last century. Programmable integrated photonics is raising considerable interest, as it is driven by the surge of a considerable number of new applications in the fields of telecommunications, quantum information processing, sensing, and neurophotonics, calling for flexible, reconfigurable, low-cost, compact, and low-power-consuming devices that can cooperate with integrated electronic devices to overcome the limitation expected by the demise of Moore’s Law. Integrated photonic devices exploiting full programmability are expected to scale from application-specific photonic chips (featuring a relatively low number of functionalities) up to very complex application-agnostic complex subsystems much in the same way as field programmable gate arrays and microprocessors operate in electronics. Two main differences need to be considered. First, as opposed to integrated electronics, programmable integrated photonics will carry analog operations over the signals to be processed. Second, the scale of integration density will be several orders of magnitude smaller due to the physical limitations imposed by the wavelength ratio of electrons and light wave photons. The success of programmable integrated photonics will depend on leveraging the properties of integrated photonic devices and, in particular, on research into suitable interconnection hardware architectures that can offer a very high spatial regularity as well as the possibility of independently setting (with a very low power consumption) the interconnection state of each connecting element. Integrated multiport interferometers and waveguide meshes provide regular and periodic geometries, formed by replicating unit elements and cells, respectively. In the case of waveguide meshes, the cells can take the form of a square, hexagon, or triangle, among other configurations. Each side of the cell is formed by two integrated waveguides connected by means of a Mach–Zehnder interferometer or a tunable directional coupler that can be operated by means of an output control signal as a crossbar switch or as a variable coupler with independent power division ratio and phase shift. In this paper, we provide the basic foundations and principles behind the construction of these complex programmable circuits. We also review some practical aspects that limit the programming and scalability of programmable integrated photonics and provide an overview of some of the most salient applications demonstrated so far.

A balanced-to-balanced directional coupler based on branch-slotline coupled structure

Abstract In this paper, a balanced-to-balanced (BTB) branch-slotline directional coupler (DC) is firstly presented, which can realize an arbitrary power division ratios (PDRs). The coupler is composed by microstrip-to-slotline (MS) transition structures and branch-slotline coupled structures. The single-ended to balanced-ended conversion is simplified and easy to implemented by the MS transition structures, which intrinsically leads to the differential-mode (DM) transmission and common-mode (CM) suppression. Moreover, the different PDRs which are controlled by the widths of branch-slotlines can be achieved. In order to verify the feasibility of the proposed design method, two prototype circuits of the proposed coupler with different PDRs are fabricated and measured. The return loss and the isolation of two designs are all better than 10 dB. Moreover, the CM suppressions are greater than 35 dB. A good agreement between the simulation and measurement results is observed.

Miniaturised wide tuning‐range four‐way quasi‐lumped‐element filtering power divider

This Letter presents a miniaturised wide tuning-range four-way filtering power divider (FPD). It is mainly developed by integrating a co-shared varactor-loaded quasi-lumped-element dual-mode resonator and an isolation resistor, achieving a wide tuning power division ratio (PDR) and centre frequency (CF) simultaneously. The presented tunable four-way FPD stands out from those in the literature, by both its improved performance (wider tuning range for PDR and CF with nice isolation and matching) and ultra-compact design layout. To validate the design concept, a reconfigurable prototype is designed, fabricated, and tested. Measured results will coincide with the simulated ones.

Reconfigurable hybrid matrix‐based power divider with variable power‐dividing ratios and frequencies

In this Letter, the authors present a reconfigurable power divider using a hybrid matrix with variable impedance tuners. The proposed hybrid matrix-based power divider with varactor-tuned impedance tuners (VTITs) can simultaneously obtain variable power-dividing ratios at the centre frequency and variable operating frequencies for the 3 dB coupling states. The VTITs, consisting of a transmission line, an inductor, and a varactor located between the line and the inductor, are connected in parallel between two hybrid couplers for high impedance variation. Measured results demonstrate that the power-dividing ratio of the proposed divider varies from -14.3 to 13.3 dB with a return loss above 20 dB and the isolation above 20 dB at a centre frequency of 2.45 GHz. Moreover, it achieves an insertion loss of 0.7-1.45 dB and a phase variation of less than 8° across the variable power-dividing ratio at the centre frequency. The frequency-tuning range for the 3 dB coupling states is 750 MHz with a small phase variation of 5°.

Design of a Simultaneous Frequency- and Power-Dividing Ratio-Reconfigurable Quadrature Coupler With Simple Tuning Approach

A simple simultaneous frequency- and power-dividing ratio- reconfigurable quadrature coupler using lumped elements is presented for reconfigurable radio applications. The theoretical analysis shows it can achieve perfect matching and isolation at all tuning states. The closed-form design equations are derived. For verification, a simultaneous frequency- and power-dividing ratio-reconfigurable quadrature coupler is designed based on the design equations. The measured 3-dB quadrature coupler is tuned from 1.8 GHz to 4.36 GHz with return loss and isolation of better than 20 dB. In addition, the measured power-dividing ratio can be tuned from −16 to 5.0 dB at 3 GHz while maintaining 20-dB return loss and isolation. As compared with state of the arts, the main merit of the proposed quadrature coupler is achievement of simultaneously wide tuning range of frequency and power-dividing ratio with the simple tuning mechanism and improved amplitude balance performance.

A generalized broadband coupled-line based rat-race coupler with arbitrary power division ratios and free terminated impedances

A generalized broadband coupled-line based rat-race coupler with arbitrary power division ratios and free terminated impedances is proposed in this paper. Besides, rigorous closed-form equations with respect to electrical parameters are derived in the section of analysis. Furthermore, one shorted coupled-line section and two identical open-circuited stubs are employed to achieve the requirement of wideband and miniaturization. Owing to additional design freedom, the calculation of parameters becomes much more flexible. For demonstration, a prototype for 6-dB wideband rat-race coupler centered at 1 GHz with the fractional bandwidth of 51.69% and free terminated impedances is designed, fabricated, and measured. Good agreement between the simulated and measured results can be observed, which can verify the validity of the proposed design principle.

Design Method for Compact Multifunctional Reconfigurable Filtering Power Divider on a New Tunable Three-Port Multi-Mode Topology

In this paper, a new effective approach is proposed to design compact multifunctional reconfigurable filtering power divider (FPD) based on a developed tunable multi-mode FPD topology. Different from conventional tunable FPD method by cascading tunable filter with power divider (PD), and double tunable filtering structures based on the tunable FPD method, it provides one promising solution of high operation performance, miniaturization and design flexibility enhancement etc., for industrial multi-functional modern wireless communication systems. By reformulating the traditional coupling matrix in terms of element-variable coupling coefficients for the developed tunable FPD topology, bandwidth (BW), center frequency (CF), as well as power division ratio (PDR) tuning are well accounted, which can help guide a new class of tunable FPD designs. For demonstration, a new second-order tunable FPD with only one common ring loaded coupled line tunable resonant unit is implemented as an example without losing generality. Higher-order tunable FPD case is further discussed and investigated by freely generalizing the FPD structure through the adoption of different tunable resonant units without dramatically increasing circuit complexity and size. Experimental results indicates that an improved performance (wider tuning range for CF, BW and PDR with nice isolation and matching), a very compact size and flexible design are achieved in the proposed work, which stands out from those in the literature.

An improved wideband three‐way waveguide power divider based on directional coupler for Ku band application

In this paper, a directional-coupler-based wideband three-way waveguide power divider is demonstrated. The proposed power divider consists of tapered rectangular waveguide, six-port directional coupler and iron pentacar-bonyl terminations. Its fractional bandwidth is 10.99% at 12.9 to 14.4 GHz. In addition, the return loss of all input and output ports is better than 20 dB and the isolation of the three output ports is more than 20 dB. Moreover, the insert loss is better than 5.19 dB including the power division ratio of 4.8 dB and the amplitude imbalance among the three output ports of less than ±0.4 dB. The experimental results agree well with the simulation ones, which indicates the validity of our method. With the above-mentioned characteristics, the proposed device can be widely used in Ku band communication systems.

Unlimited Power Division Ratio of Microstrip Balanced-to-Unbalanced Gysel-Type Arbitrary Power Divider

A microstrip balanced-to-unbalanced (BTU) Gysel-type arbitrary power divider without the high-impedance transmission-line (TL) section is proposed to eliminate the power division ratio (PDR) limit of the conventional microstrip BTU power dividers. The proposed circuit includes five moderate-impedance TLs having the same characteristic impedance in addition to a grounded resistor. The arbitrary PDR is easily obtained by varying the electrical length of the TLs without changing the characteristic impedances, especially the large PDR, which is difficult to achieve by means of conventional BTU power dividers. When the PDR is ∞, the proposed circuit becomes a balun. The closed-form design equations are derived and discussed. To verify the proposed circuit, three prototypes I, II, and III are designed and fabricated for PDRs of 10 dB, 20 dB, and ∞ dB, respectively. The measured PDRs are in good agreement with the simulations. The measured isolation between the output ports is higher than 31 dB for prototypes I and II. The measured insertion loss of the balun prototype is 0.194 dB. Furthermore, the common-mode suppression of greater than 32 dB and the return loss of higher than 22 dB are obtained for various PDRs.

Synthesis of Multi-Port Filtering Power Divider for Mixed Topology Using Matrix Optimization

In this brief, a direct synthesis method is proposed to extract the coupling matrix of multi-port filtering power divider (FPD) for mixed topology for the first time. Different from the existing cross-coupled configuration, extracted pole based topology containing non-resonating nodes (NRN) is introduced into the multi-port FPD network to eliminate some inherent limitations. All the elements of coupling matrix are obtained directly in the synthesis process by optimizing the cost function with the deigned Quantum Particle Swarm Optimization (QPSO) algorithm in this brief, avoiding evaluating the numerical value one by one from the conventional two-port filter synthesis method and eliminating the step of similarity transformations of the coupling matrix. Moreover, impedance matching has been considered to the FPD synthesis process to meet the comprehensive needs of more scenarios. Several numerical examples of FPD with equal/unequal power division ratios and arbitrary reference impedance, different responses for both symmetrical and asymmetrical mixed topologies are synthesized to verify the proposed synthesis method.

Arbitrary terminated negative group delay circuit using signal interference concept

In this article, we demonstrate signal interference concept based wideband negative group delay (NGD) circuit with an arbitrary termination port impedance. The proposed circuit consists of unequal power division ratio 180° hybrid and in-phase combiner. The NGD can be generated by controlling power division ratios of 180° hybrid and combiner. For experimental verification, the circuit is designed and fabricated at a center frequency of 2 GHz. The experiment results show that the proposed NGD circuit can provide 460 MHz NGD bandwidth (bandwidth of group delay <0 ns) with group delay of −0.8 ns at 2 GHz.

Compact wideband differential filtering power divider based on three‐line coupled structure with lumped elements

A wideband differential filtering power divider using three-line coupled structure with multiple lumped elements is proposed. The equal power division ratio, filtering response, isolation and common-mode suppression are mainly derived from the symmetrical structure, three-line coupled lines with capacitors, resistors and the short lines along the vertical symmetrical line, respectively. Compared to the reported differential filtering power dividers, the proposed design shows advantages of wide bandwidth, compact size and low insertion loss (IL). A prototype with the small size of 0.5λ g × 0.08λ g (λ g is the guided wavelength at the centre frequency) was designed for demonstration, which exhibits the 3 dB fractional bandwidth of 79.2% and the minimum IL of 0.48 dB.

Multilayer Packaging SIW Three-Way Filtering Power Divider With Adjustable Power Division

A new three-way filtering power divider (FPD) design based on multilayer substrate integrated waveguide (SIW) with equal/unequal power division is proposed in this brief. By elaborately integrating three same-type slotline-microstrip transition structures with a pair of TE101-mode resonant cavities, dual-mode three-way filtering power division response is attained in the design. Owing to the loading effect of the common coupling slot, one transmission zero is generated to improve lower passband selectivity. Furthermore, three-way equal and unequal power division can be achieved by flexibly changing the length of the microstrip line beyond the coupling slot. Simultaneously, favorable in-band port-to-port isolation is obtained by loading isolation resistors between the three output microstrip lines. For demonstration, two FPD prototypes with different power division ratios (1:1:1 and 1:1:1.5) operating at 11.8 GHz are designed, fabricated, and tested. The measured results agree well with the simulation results, verifying the presented design concept.

Novel Reconfigurable Filtering Rat-Race Coupler, Branch-Line Coupler, and Multiorder Bandpass Filter With Frequency, Bandwidth, and Power Division Ratio Control

In this article, for the first time, a novel four-port coupler with reconfigurable multifunctions of filtering rat-race coupler (FRC), filtering branch-line coupler (FBC), and conventional single-ended two-port multipole bandpass filter (BPF) is proposed. It simply consists of four varactor-loaded stepped-impedance resonators that are arranged symmetrically. Through appropriate coupling-type (electrical coupling or magnetic coupling) conversion, 90° or −90° phase shift between the adjacent resonators can easily be obtained and works as a key factor in the transformation between different filtering coupler modes. With this simple configuration, the proposed coupler achieves reconfigurable FRC and FBC with not only operating frequency tuning over a wide tuning range but also bandwidth and power division ratios (PDRs) control for each filtering mode. In addition, by imposing open circuit at any two ports, the four-port coupler can be converted to the conventional single-ended two-port BPFs with reconfigurable filter orders of second, third, and fourth. The measured results show that the FRC and FBC can continuously cover the frequency ranges of 1.21–1.67 and 1.2–1.61 GHz with −1-dB bandwidth tuning of 60–120 and 55–110 MHz, respectively. The 3- and 6-dB PDRs have been demonstrated for both filtering coupler modes. In single-ended two-port BPF mode, the frequency tuning ranges are measured of 1.12–1.6, 1.16–1.6, and 1.2–1.61 GHz, respectively, for the proposed two-port second-, third-, and fourth-order BPFs. Measured and simulated results are in good agreement, validating the proposed design method.

Dual‐band Gysel power dividers with large frequency ratio and unequal power division

In this article, a dual-band Gysel power divider is proposed based on the topology of finite-ground microstrip line. The general design method for the large frequency ratio and unequal power division is derived and the detailed design rules are provided. It is shown that the frequency ratio can be achieved from 1 to 10, and the power division ratio of each frequency band can be separately determined. Moreover, the phase differences at two operating bands could be designed to be either in-phase or out-of-phase. Finally, two prototypes are designed, implemented, and experimented to validate this proposal. The measured results of the first design show the frequency ratio of 4 with power division ratios of 2:1 in both passband, while the second example is designed with the frequency ratio of 10 with power division ratios of 2:1 and 1:1 in the first and second passband, respectively. Both results show a good agreement between the simulated and measured results.

Novel Tunable Isolation Network Used in Ring-Type Single-to-Balanced, Power-Dividing, and Single-Ended Filter With Arbitrary Power-Division Ratios

In this article, a novel tunable isolation network and a novel ring-type reconfigurable single-to-balanced (SE-BAL), power-dividing (PD), and single-to-single-ended (SE) bandpass filter is proposed. The tunable isolation network consists of a simple $\pi $ -type resistive network with tunable varactors, while the proposed filter consists of three ring-type stepped impedance resonators (SIRs) connected by varactors in between. By simply combining the proposed tunable isolation network and the proposed ring-type reconfigurable filter, it can achieve multiple reconfigurable functions among SE-BAL filtering, PD filtering, and conventional SE filtering with fully matched three ports, arbitrary power-division ratios (PDRs), high output isolations, and excellent amplitude and phase balance, in addition to continuous frequency and independent bandwidth tuning. The proposed filter is demonstrated using the microstrip line technology. The measured results show that the SE-BAL, PD, and two SE filtering functions can continuously cover the frequency ranges of 1.03–1.61, 1.01–1.53, 1.03–1.56, and 1.06–1.48 GHz with −1-dB bandwidth tuning of 35–80, 50–140, 60–130, and 70–140 MHz, respectively; the 1-, 3-, and 5-dB PDRs have been demonstrated for both SE-BAL and PD filtering modes. The measured output return losses and isolation are better than 19 and 18 dB, respectively, for SE-BAL filtering mode and 20 and 16 dB, respectively, for PD filtering mode. Good agreement is obtained between the simulated and measured results.

W‐band out‐of‐phase active power divider with continuously tunable power division ratio and invariant phase difference

In this study, a W-band out-of-phase active power divider, with continuously tunable power division ratio, has been presented. Out-of-phase signal is generated by the compact transform balun with accurate phase and amplitude response. To stabilise the phase difference in different power division ratio, phase-invariant cascode variable gain amplifier (VGA) is designed in the two paths of the active power divider and 4-bits proportional to absolute temperature current source is designed to control voltage of VGA. The active power divider is implemented in SiGe BiCMOS process with measured tunable power division ratio from 1:16 up to 16:1, the phase shift from 74 to 90 GHz is about 10° as the gain changes up to 12 dB, which guarantees a good phase-invariant performance.