Two-way Wilkinson Power Divider Research Articles

Miniaturization of microwave planar circuits using composite microstrip/coplanar-waveguide transmission lines

The rapid development of modern communication systems propels the demand of high performance and miniaturization of RF/microwave components. Power dividers and filters are indispensable circuit components in amplifiers and antenna feed-networks which occupy large footprint of circuit broads, particularly at low frequency. The purpose of this study is to initiate a new type of planar transmission line with unique dual signal-path characteristics and ultimately achieve circuit miniaturization. In this paper, a novel technique of consolidating microstrip lines (MLs) and coplanar waveguide (CPW) lines on a single dielectric substrate, designated as the composite microstrip/CPW line (CM/CPW line), is proposed. With reference to the average line length of ML and CPW, it warrants a physical length reduction of 48.3% and further achieves a reduction of 80.8% after zigzagging CM/CPW line. The proof-of-concept design example of a two-way Wilkinson power divider (WPD) has demonstrated the effectiveness of the miniaturization technique. The simulation, in combination with the experimental results, validates that a size reduction factor of 86.9% when compared to conventional one has been achieved while maintaining a fractional bandwidth of 57.7% for the WPD.

Design and analysis of low-insertion-loss G-band CMOS four-way Wilkinson power dividers and dual balun

We present the design and analysis of G-band CMOS Wilkinson power dividers and dual balun for G-band communication and imaging systems. Miniature spiral and U-shaped four-way Wilkinson power dividers, which are based on three two-way Wilkinson power dividers, are designed and implemented. Miniature spiral dual balun, which is equivalent to an upper balun and a lower balun in parallel, is also designed and implemented for comparison. These devices are planar and symmetrical, and their main structure is implemented by the 2.34-µm-thick topmost metal to minimize the resistive loss. This leads to low insertion loss, and small amplitude imbalance (AI) magnitude and phase difference (PD) deviation. For instance, the spiral four-way Wilkinson power divider occupies 0.033 mm2 chip area and achieves S11 of − 11.4 dB, S21 of − 6.271 dB, S31 of − 6.445 dB, S41 of − 6.676 dB, and S51 of − 6.111 dB at 180 GHz, one of the smallest chip areas and lowest insertion losses for four-way power dividers with similar operation frequency. The corresponding AI magnitude and PD deviation are 0.565 dB and 3.2°, respectively. Moreover, the spiral dual balun occupies 0.026 mm2 chip area and achieves S11 of − 10.6 dB, S21 of − 7.549 dB, S31 of − 7.1 dB, S41 of − 7.598 dB, and S51 of − 7.352 dB at 180 GHz. The corresponding AI magnitude and PD deviation are 0.498 dB and 5.7°, respectively. The prominent results of the spiral and U-shaped four-way Wilkinson power dividers, and the spiral dual balun indicate that they are suitable for power division/combination in G-band systems.

Design and analysis of four-way power divider for 94 GHz power amplifiers in 90 nm CMOS process

A millimeter-wave miniature CMOS dual-balun-based four-way power divider is reported. The four-way power divider can be applied to a four-way power amplifier (PA) for four-way power dividing or a star mixer for converting the single RF (or LO) input signal to dual differential RF (or LO) signals. In contrast to the traditional four-way PA that uses three two-way Wilkinson power dividers for four-way power dividing, the proposed PA architecture achieves smaller chip area, and higher output power and power-added-efficiency. The four-way power divider occupies a small chip area of 0.16 mm × 0.408 mm (i.e., 0.065 mm2) and achieves S11 smaller than − 10 dB for frequencies of 87.3–101.1 GHz. For frequencies of 94 GHz, the four-way power divider achieves S11 of − 12.2 dB, S21 and S41 of − 8.08 dB, S31 and S51 of − 8.09 dB, and magnitude of amplitude imbalance (MAI) of 0.006 dB and phase difference (PD) of 177° for ports 2–3 and 4–5. For frequencies of 90–100 GHz, the four-way power divider achieves S11 of − 10.5 to − 12.3 dB, S21 and S41 of − 8.09 to − 8.31 dB, S31 and S51 of − 7.9 to − 8.45 dB, and MAI of 0–0.19 dB and PD of 176.8°–178.1° for ports 2–3 and 4–5. The state-of-the-art results of the proposed four-way power divider indicate that it is suitable for 94 GHz image radar sensors.

A Two-Way Wilkinson Power Divider Realized Using One Eighth Wave Transmission Line for GSM Application

A Two-Way Wilkinson Power Divider Realized Using One Eighth Wave Transmission Line for GSM Application

Compact coplanar interferometer for a 5–6 GHz IFM system

The authors present a new compact coplanar interferometer for application in an IFM system with 4 bits that operates in a frequency band from 5 to 6 GHz. This interferometer consists of a couple of coplanar two-way Wilkinson power dividers connected to two CPS lines with different signal delays. This interferometer presents smaller dimensions when compared to other designs. Details of this compact coplanar interferometer are provided along with a comparison between theoretical, simulated and measured results.

A novel symmetrical Wilkinson power divider for dual-band application

A symmetrical two-way Wilkinson power divider with shifted output ports, much wide bandwidth and large frequency-ratio is proposed for dual-band application. The corresponding transcendental design equations are derived by using the even- and odd-mode analysis. Moreover, the closed-form scattering parameter expressions are derived. Transcendental design equations are solved and accurate numerical design parameters along with different frequency ratios are obtained. Finally, the proposed structure and design method are validated by simulated and experimental results of typical microstrip planar power dividers, the performance is clearly observed for the input and output matching, isolation and transmission characteristic very well at the two band frequencies. More specifically, the measured transmission characteristics of the divider are 3.11 dB/3.58 dB at the 1.0 GHz/3.5 GHz, respectively. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:102–108, 2014.

Packaging test-fixture research for 10–12 GHz frequency detector based on thermoelectric microwave power sensor

To show the performance of a 10-12 GHz frequency detector embedded into real-life RF communication circuit systems, a packaging test-fixture research is presented. The principle of the frequency detector is based on the phase delay detection of two separated signals divided by a two-way Wilkinson power divider. The phase delay is proportional to the frequency of the input microwave signal and gives rise to variation of output power. The thermoelectric microwave power sensor is adopted to measure the variation. In this design, the packaging method is based on the transition of the input CPW- based port of the frequency detector, a microstrip line and an SMA connector. Fabrication of the package is performed and the layout size of the packaging test-fixture is 40 × 30 mm 2 . Experiments show that whether before or after the packaging, the measured output thermovoltages both approximate to decrease linearly with respect to the frequency of the RF signal. The after-packaging sensitivities are 0.031, 0.104 and 0.317 μV·MHz -1 under RF signals of 10, 15 and 20 dBm, respectively, while the before-packaging sensitivities are 0.030, 0.103 and 0.305 μV·MHz -1 , respectively.

A Design Methodology for Miniaturized Power Dividers Using Periodically Loaded Slow Wave Structure With Dual-Band Applications

This paper proposes an analytically-based approach for the design of a miniaturized single-band and dual-band two-way Wilkinson power divider. This miniaturization is achieved by realizing the power divider's impedance transformers using slow wave structures. These slow wave structures are designed by periodically loading transmission lines with capacitances, which reduces the phase velocity of the propagating waves and hence engender higher electric lengths using smaller physical lengths. The dispersive analysis of the slow wave structure used is included in the design approach to ensure a smooth nondispersive transmission line operation in the case of dual-band applications. The design methodology is validated with the design of a single-band, reduced size, two-way Wilkinson power divider at 850 and 620 MHz. An approximate length reduction of 25%-35% is achieved with this technique. For dual-band applications, this paper describes the design of a reduced size, two-way Wilkinson power divider for dual-band global system for mobile communications and code division multiple access applications at 850 and 1960 MHz, respectively. An overall reduction factor of 28%, in terms of chip area occupied by the circuit, is achieved. The electromagnetic simulation and experimental results validate the design approach. The circuit is realized with microstrip technology, which can be easily fabricated using conventional printed circuit processes.

A semi-automatic 3-port network analyzer

A semi-automatic three-port network analyzer has been developed. The three-port network analyzer consists of an automatic two-port network analyzer, a switching network for RF rerouting and a software package. The design of the three-port network analyzer is based on a new method for obtaining accurate three-port S-parameters from measured two-port parameters. This method is based on a flow-chart description of the measurements. The resulting overdetermined nonlinear equation system is solved numerically. No assumptions are made about the device under test or the terminations apart from that the latter must be known. The efficiency of the method is demonstrated by characterization of a two-way Wilkinson power divider. The three-port network analyzer has been used to characterize dual-gate MESFETs. >