A simple and compact three-way planar power divider, which avoids the floating common node of the isolation resistors, is presented. The proposed structure exhibits a wideband operation (measured frequency range of 1.6–3.3 GHz and bandwidth of 69.4%) with good return loss and isolation characteristics. Transmission line theory is used for the mathematical analysis and extraction of design equations, followed by simulations and experimental measurements that confirm the predicted results. The proposed divider achieves an equal power split (∼32%, −4.9 ± 0.4 dB insertion loss) between the input and each output port. The measured return loss is better than −10 dB at all ports, and the measured maximum isolation is close to −30 dB. The proposed design exhibits a fully planar structure, thus eliminating the need for a floating common node for the isolation resistors. Additionally, its structure is much simpler (i.e., no coupled lines, crossovers, or lumped capacitors are required) than other designs, achieves wideband operation, and provides design simplicity, flexibility, and easy implementation. Despite its simple noncomplicated structure, the proposed three-way planar divider achieves similar (or in some cases, better) performance and size than other more complicated structures. Furthermore, it can be expanded to an n-way structure.

A waveguide power divider based on ridge waveguide to microstrip line transition is presented in this paper. To improve the isolation performance, a probe insulator is inserted into the contact face from the center of the waveguide side wall, also two chip resistors are mounted on a planar substrate and connected with the probe to absorb the coupled energy. The impedance transformation is accomplished by ridge waveguide to microstrip line transition, which is hidden in the waveguide. This proposed power divider shows merits of waveguide power dividers and substrate-integrated waveguide power dividers simultaneously, i.e. planar output ports, compact size, and high isolation. For verification, a power divider operating at the Ka-band is simulated, fabricated, and measured. The obtained results show the return loss and isolation are better than 10 and 20 dB, respectively. The measured insertion loss is <1.5 dB, including the insertion loss of waveguide to microstrip line transitions at the output port in the range of 34.6–39 GHz.

Exposing the near field of an antenna to varying dielectric environment causes changes of the antenna input impedance and, thus, unwanted feed mismatch. Feeding such an antenna at different points, and selecting an appropriate feed for best match at a given scenario, may solve the problem. For the case of two scenarios of different dielectric environments and an antenna with two feed points, this work presents a passive power divider network, which keeps the antenna matched to the source in either scenario. Specific impedance transformations in the two branches of the divider network realize power transfer in a first scenario from the source to complex feed impedance at the first antenna feed, while in a second scenario, with now different antenna feed impedances, matched power transfer is from the source to the second antenna feed. Analytical formulae are derived for the design of the divider network. An experiment uses an example antenna with two feeds and a microstrip divider network, connected to a common 50 ohm port. Measurements are conducted with the antenna radiating, first, in air and, secondly, into butter. The measurements show antenna match at 1 GHz in either case and agree well with the analytical results.

This paper presents a miniaturized tri- and quad-band power divider (PD)based on substrate integrated waveguide (SIW). By adopting different types of modified circular complementary split-ring resonators on the top surface of SIW, multiple passbands are generated propagating below the SIW cut-off frequency. The working principle is based on evanescent mode propagation that decreases the operating frequency of the PD and helps in the miniaturization of the proposed structure. The operating frequency of the proposed PD can be individually controlled by changing the dimensions of the resonator. To verify the proposed concept, a tri-band and a quad-band PD exhibiting 3 dB equal power division at 2.41/3.46/4.65 GHz and 2.42/3.78/4.74/5.8 GHz are designed using the full-wave simulator, validated through circuit model, fabricated and experimentally verified. The measured results agree well with the simulations. The proposed PDs have good performance in terms of reasonable insertion loss, isolation, minimum amplitude and phase imbalance, smaller footprint, easy fabrication and integration. The size of the fabricated prototype is 18.3 mm × 8.4 mm, which corresponds to 0.205λg × 0.094λg, λg being the guided wavelength at the first operating frequency.

The paper proposes a system consisting of novel programmable system on chip (PSoC)-controlled phase shifters which in turn guides the beam of an antenna array attached to it. Four antennae forming an array receive individual inputs from the programmable phase shifters (IC 2484). The input to the PSoC-based phase shifter is provided from an optimized 1:4 Wilkinson power divider. The antenna consists of an inverted L-shaped dipole on the front and two mirrored inverted L-shaped dipoles mounted on a rectangular conductive structure on the back which resonates in the ISM/Wi-Fi band (2.40–2.48 GHz). The power divider is designed to provide the feed to the phase shifter using a beamforming network while ensuring good isolation among the ports. The power divider has measured S11, S21, S31, S41, and S51 to be −14, −6.25, −6.31, −6.28, and −6.31 dB, respectively at a frequency of 2.45 GHz. The ingenious controller is designed in-house using a PSoC microcontroller to regulate the control voltage of individual phase shifter IC and generate progressive phase shifts. To validate the calibration of the in-house designed control circuit, the phased array is simulated using $s_p^2$ touchstone file of IC 2484. This designed control circuit exhibits low insertion loss close to −8.5 dB, voltage standing wave ratio of 1.58:1, and reflection coefficient (S11) is −14.36 dB at 2.45 GHz. Low insertion loss variations confirm that the phased-array antenna gives equal amplitude and phase. The beamforming radiation patterns for different scan angles (30, 60, and 90°) for experimental and simulated phased-array antenna are matched accurately showing the accuracy of the control circuit designed. The average experimental and simulated gain is 13.03 and 13.48 dBi respectively. The in-house designed controller overcomes the primary limitations associated with the present electromechanical phased array such as cost weight, size, power consumption, and complexity in design which limits the use of a phased array to military applications only. The current study with novel design and enhanced performance makes the system worthy of the practical use of phased-array antennas for common society at large.

A four-way suspended-stripline power divider is presented in this letter. The power dividing network is designed by using the suspended stripline, while the isolation network is designed by using the microstrip line. The vias are used to connect the power dividing network and the isolation network. The even- and odd-mode analysis method is applied to design the presented power divider. The simulated and measured results of the presented power divider show reasonable agreement with each other. The measured input return loss in the band is greater than 28 dB (7.92 to 9.53 GHz), while the measured insertion loss is less than 0.37 dB. The measured output return loss is greater than 20 dB from 7.82 to 9.86 GHz. Besides, the measured output isolation is greater than 20 dB.

A compact wideband out-of-phase power divider (PD) with improved isolation performance is proposed. This divider is formed by connecting an additional stub for isolation to output ports of a traditional Marchand balun with a defected ground structure (DGS) been used. To verify the design, a prototype divider is fabricated and tested. The measured results validate the 53.86% band-width centered at 3.43 GHz with more than 15 dB return loss at all ports, more than 17 dB isolation, respectively.

The ultra-wideband bandpass-response power divider with high-frequency selectivity is presented in this paper. This power divider consists of an impedance transformer, a filter network, and two isolation resistors. In order to realize the ultra-wideband filtering performance, parallel coupling lines and parallel open-circuit branches are applied to the second impedance converter. A resistor is added to the ends of the coupling lines to achieve good isolation and output return loss. The equivalent-circuit method is employed to analyze the presented power divider. The power divider, working at 3.45–8.29 GHz, is designed and fabricated. Two transmission zeros are generated at 2.8 and 9 GHz, respectively, and the out-of-band suppression is >13 dB. The measured results are in good agreement with the simulation ones.

In this study, wideband bandpass power divider with good out-of-band performance is proposed. Two bandpass filters (BPFs) are utilized to substitute the quarter-wavelength transmission line in conventional Wilkinson power divider. A resistor is specially arranged between two BPFs for a good isolation. Four transmission zeros (TZs) are found to be distributed in the lower and upper stopband of the power divider. Moreover, the locations of two TZs can be shifted by tuning the impedance ratio of the center-loaded open stub, which is propitious to improve the frequency selectivity. Even- and odd-mode methods are applied to analyze the proposed power divider and closed-form design formulas are obtained. Finally, two prototype power dividers with measured rejection level in the upper stopband larger than 29.1 and 32 dB till to 2.7f0 and 2.69f0, respectively, are designed and fabricated to testify the proposed design concept. Good agreement between the simulated and measured results is observed, validating the validity of the proposed design principle.

A novel Gysel power divider with high power-handling capability based on half-mode substrate integrated waveguide (HMSIW) has been presented in this paper. A HMSIW ring is used and good input/output impedance matching is achieved based on HMSIW-microstrip taper transition. Two microstrip stubs are introduced in HMSIW ring to assemble two isolation resistors to improve the isolation between the output ports. The even- and odd-mode analysis method is used for the presented circuit. A prototype of the presented power divider is designed, fabricated, and measured. The measured results show a reasonable agreement with the simulated ones.

A compact multi-layer N-way power-dividing structure with good isolation and output return loss performance is proposed. The isolation network is circularly distributed that constitutes a closed ring-shaped architecture. The equivalent circuit model is given and the [S] matrix is developed to analyse and design the power-dividing structure. Finally, a six-way power divider centered at 2.1 GHz is designed and fabricated. The measured and simulated results agree well with each other. The total size of the power divider is 0.13λg × 0.19λg.

A wide-stopband bandpass-filtering power divider with high-frequency selectivity has been proposed in this paper. The input and output feeding lines and eight 1/4 wavelength resonators are used to realize the signal transmission. In order to obtain good frequency selectivity, source-load coupling transmission path is used to generate transmission zeros near the passband. A four-way power divider with bandpass-filtering response and high-frequency selectivity is designed, fabricated, and measured. The measured results agree with the simulated ones closely in the desirable frequency range. The measured center frequency of the power divider is 2.38 GHz with input return loss of 31.2 dB, while the measured insertion loss is about 1 dB (not including ideal 6 dB four-way power dividing insertion loss). Moreover, the measured 3-dB bandwidth is 12% and the measured stopband attenuation is >15 dB from 2.59 to 7.7 GHz. In addition, two transmission zeros of 1.9 and 2.8 GHz are located near the passband. The measured output isolations are all >15.7 dB.

Design and realisation of a compact power divider based on half mode substrate integrated waveguide (HMSIW) with an arbitrary power dividing ratio is presented. This design consists of a substrate integrated waveguide (SIW) transition, two bisected HMSIW transitions by a gap, an SIW-to-microstrip transition, and two microstrip feed lines. In addition, a resistor is attached between two HMSIW transitions. To adjust the power division ratio, four parameters are introduced. Furthermore, four graphs are plotted using a three-dimensional electronmagnetic (3D EM) simulator to graphically determine the introduced parameters. In this study, three circuits with power division ratios of 1:1, 1:4, and 1:8 are simulated using the 3D EM simulator and fabricated on a Rogers RO4003C substrate. The results show a good agreement between the simulated and measured results. The measured results display these circuits (1:1, 1:4, and 1:8) have the bandwidths of 70, 36, and 40%, respectively. Moreover, the proposed structures (1:1, 1:4, and 1:8) are compact and their overall sizes are $1.13 \times 1.04\lambda _g^2 $, $0.96 \times 0.91\lambda _g^2 $, and $0.81 \times 0.78\lambda _g^2 $, respectively. These structures have the advantages of the compactness in size, wide bandwidth, high power division ratio (from 1:1 to 1:16), and compatibility with planar circuits.

A broadband six-way out-of-phase substrate-integrated waveguide (SIW) power divider was designed, analyzed, and fabricated for low loss and out of phase dividing applications. The SIW technology was used to realize the power divider; where it consists of a central dual-disc probe connected with coaxial outer-conductor impedance matching transformer and six SIW-to-microstrip transitions as output probes. Three of the SIW-to-microstrip transitions are located at the top plane, whereas the other three are at the bottom plane of the power divider to achieve the out-of-phase dividing functioning. These transitions are all the same in size and shape for symmetry reason. Good transmissions from coaxial input port to six-way SIW power divider were also achieved. There is a reasonable agreement between measured and simulated results.

A novel compact ultra-wideband (UWB) eight-way ring-cavity power divider is presented in this paper. To broaden the bandwidth of the power divider/combiner, the stepped-impedance technology is used to realize the impedance match. The network of this eight-way ring-cavity power divider has been analyzed. The measured results reasonably agree with the simulated ones. The measured return loss is greater than 10 dB from 5.2 to 18.6 GHz. The average insertion loss, amplitude imbalance, and phase imbalance are around 9.4 dB (including the 9-dB power-dividing insertion loss), ±0.7 dB, ±6°, respectively, across the entire operating frequency range.