Generalized high‐isolation n‐way Gysel power divider with arbitrary power ratio and different real terminated impedances

This chapter discusses several kinds of balanced-to-balanced power divider/ combiner. As the key component in a balanced RF transceiver, the concept of balanced-to-balanced power divider/combiner is proposed, which divides the input differential-mode power into several ways with good port isolation and common-mode suppression. To extend the applications of balanced-to-balanced power dividers, the chapter designs a dual-band balanced-to-balanced power divider. It introduces balanced-to-balanced Wilkinson power dividers implemented using microstrip technology. The desired performance of the balanced-to-balanced Gysel power divider has been implemented with the half-mode substrate integrated waveguides (SIWs) ring structure, and a high power handling capability can be expected. The balanced-to-balanced power dividers are designed in Wilkinson and Gysel topologies and realized in microstrip line and half-mode SIW. They are also designed with arbitrary power division ratio, bandpass filtering response, and dual-band operation.

A planar miniaturized asymmetrical four-port circuit structure based on the composite left- and right-handed transmission lines (CLRHTLs) is proposed in this paper to design a balanced-to-single-ended (BTSE) power divider (PD) with arbitrary power division. The two outputs of the power divider are in-phase, hence, the proposed circuit can be seen as the cascade of a balun and a Gysel power divider with arbitrary power division. The matrix conversion between the single-ended scattering parameters and the mixed-mode scattering parameters along with the circuit analytical formulation are presented. Finally, a prototype of the PD with 2 dB magnitude difference between its output ports is designed and fabricated. The measured results validate the proposed design approach.

Omnidirectional conformal microstrip array antenna with electronically beam switching capabilities for 5G applications

A novel Gysel power divider, which can be fabricated without a need for any high-impedance transmission-line section (TL), even for the power-division ratios higher than 15 dB, is presented. To derive its design formulas, a new study on the conventional in-phase T-junctions is carried out, and two conditions are newly derived for the arbitrary power-division ratios and perfect matching at all the ports, which can be applied for any symmetric or asymmetric Gysel power divider without any additional effort to design the isolation circuit. As a proof-of-concept demonstration, two prototypes I and II at the design frequency of 1 GHz are fabricated for the power-division ratios of 17 and 20 dB, respectively. Such power-division ratios have never been tried before not only for the Gysel power dividers but also for generic planar power divider topologies without the use of high-impedance TLs for the wider bandwidths. The measured results are in good agreement with the predictions.

A novel RF power divider for CDMA (1.8GHz), Bluetooth (2.4GHz) & 3G (2.1GHz & 2.5GHz) application using stepped-impedance technology on microstrip line is proposed in this paper. This divider is formed by installing the concept of a microstrip multi-section impedance transformer and for achieving of wideband using stub matching. Finally, a compact power divider is designed, and it is demonstrated that 9dB powers splitting from one input port to eight output ports is achieved. In addition, good impedance matching at all the three ports and excellent isolation between two output ports are obtained over the specified 1.7–2.6GHz wideband range. The simulated return loss is greater than 10 dB over the WB. The average insertion loss, and group delay are around 9dB (including the 9-dB power-dividing insertion loss) and around 0.3 ns over across the wideband. In addition, the isolations between the output ports are greater than 10 dB over the wideband.

An ultra-wideband (UWB) power divider on microstrip line is proposed, analyzed and designed. This divider is formed by installing a pair of stepped-impedance open-circuited stubs and parallel-coupled lines to two symmetrical output ports. In addition, a single resistor is properly placed between two output ports. After simple transmission line theory analysis, it is demonstrated that 3 dB power splitting from one input to two output ports, good impedance matching at all the three ports and excellent isolation between two output ports are achieved over the specified 3.1-10.6 GHz UWB range. Finally, a prototype divider is fabricated and measured to provide an experimental verification on the predicted attractive features.

In this paper, the topology of four-way unequal Gysel power divider with arbitrary power dividing ratio is proposed. Complete design equations are firstly available for designing four-way unequal Gysel power dividers. To verify our theory, a power divider with power dividing ratio 1:1.5:2:2.5 is designed, fabricated and measured. The measured 15 dB bandwidth of return losses is about 14.97% while the isolation of the output ports is 18.75 dB, showing good agreement with simulated results. The measured amplitude distributions are also consistent with expected values.

Ultra wideband components have been developed using SIW technology. The various components including a GCPW transition with less than 0.4 dB insertion loss are developed. In addition to, T and Y-junctions are optimized with relatively wide bandwidth of greater than 63% and 40% respectively that have less than 0.6 dB insertion loss. The developed transition was utilized to design an X-band 8 way power divider that demonstrated excellent performance over a 5 GHz bandwidth with less than ±4° and ±0.9 dB phase and amplitude imbalance, respectively. The developed SIW power divider has a low profile and is particularly suitable for circuits' integration.

This letter describes a low‐profile three‐way fan‐shaped power divider integrable with aperture‐coupled antenna arrays. Each unit element is designed with a circular cavity‐based eighth‐mode substrate integrated waveguide. For better impedance matching, tapered feedlines are used at the output side. This structure is well suited for aperture‐coupled antenna arrays with a ground plane between the two substrates. The low‐profile power divider offers a 1 dB insertion loss (excluding the ideal power division of 4.8 dB). Magnitude and phase imbalance between output ports is dB and , respectively. The performance of the power divider is validated by using it as a feeding circuit for an aperture‐coupled array antenna with three circular patches. The antenna array resonates at 10.5 GHz and gives a gain of 4 dBi.

Frequency bandwidth and performance of power dividers depend on their amplitude and phase imbalances besides their return loss. In this paper, for compact 2-way H-plane power dividers, 2 structures are proposed. Furthermore, designs for different ratios of output powers i.e. |S21 / S31|2 almost equal to 0, 1.5, 3, 4.5 and 6 (dB) are presented in both structures and their simulation results are compared. Result of simulations approve that by increasing the power ratio of |S21 / S31|2 the phase and amplitude imbalances of designed power dividers get worse. Nevertheless, for one of the proposed structures, in frequency band of 16–18GHz, designing a power divider with power ratio of 10 Log (|S21 / S31|2)= 6 ± 0.45 (dB), and phase imbalance ≤ ±4.3 degrees, and |Sn| ≤ −24 (dB) is achievable.

In this paper, a new design of Gysel power divider with good performance and very compact size is presented. In this design, rectangular resonators and U shaped transmission lines are used. Operating frequency that is considered is 580 MHZ. The proposed power divider only takes 15.83% of the area of the corresponding conventional Gysel power divider. Proposed equal low pass filters are replaced with transmission lines and the harmonics suppression is also improved. In this design, 10 harmonics are suppressed. Finally, the proposed power divider is fabricated and a good match is found between the simulation and measurement results.

This article presents a bandpass‐filtering power divider with a controllable and wide spurious frequency. The proposed structure consists of four stepped‐impedance resonators (SIR) that are directly coupled to the output ports of the power divider with an electrical length of θ. The spurious frequency can be controlled by changing the ratio of the SIR. Moreover, the isolation resistor provides an effective isolation between the output ports and an effective output return loss over wide stopbands. For the experiment validation, the power dividers with the stepped‐impedance ratios of 0.83 and 1.43 were designed, fabricated, and measured at the center frequency of 2.6 GHz. The measured results are in good agreement with the simulated results.

Two new wideband four-way out-of-phase slotline power dividers are proposed in this paper. The half-wavelength slotlines are employed to construct the presented compact power dividers. Based on the proposed power-dividing circuit, a four-way power divider is implemented with compact size and simple structure. To obtain high isolation among the four output ports and good output impedance matching, another four-way out-of-phase slotline power divider with improved isolation performance is designed by introducing an air-bridge resistor and two slotlines with isolation resistors. The simulated and measured results of the proposed power dividers demonstrate reasonable performance of impedance matching, insertion loss, amplitude balancing, and isolation among the output ports.

A new uniplanar monolithic microwave integrated circuit (MMIC) balun using lumped circuits is presented. The proposed planar balun consists of a wideband Wilkinson power divider and a broadband 180° phase shifter using novel series and parallel LC reflective terminating circuits. To demonstrate the design methodology, a 24–44 GHz MMIC balun was realised as a 1.4 mm2 GaAs chip. The measured return losses for the unbalanced and balanced ports are better than −12, −10 and −7 dB, respectively. The measured amplitude and phase imbalance between the two output ports are less than 0.5 dB and 7°, respectively, and maximum insertion loss is 5 dB.

A 4-way power divider with continuously tunable power-dividing ratio is presented in this paper. The power divider works in the 3.5 GHz band for 5G applications. The 4-way divider is constituted by connecting three 2-way tunable power dividers, and its power-dividing ratio can be continuously adjusted within a certain range by simply adjusting the bias voltages of three varactors. In this paper, four typical feed requirements of 4-element antenna array are taken, for example, to verify the performances of the 4-way power divider, they are uniform feed of 1: 1: 1: 1; symmetric and non-integer feed of 1: 5.9: 5.9: 1; symmetric and large power-dividing ratio feed of 1: 9: 9: 1; asymmetric non-integer feed of 1: 2.2: 3.8: 7.9. The simulated results show that the radiation patterns of a 4-element microstrip antenna array using this feed network are different at the four different states, and the beamforming and pattern reconfiguration of the antenna array can be realized easily.