Wilkinson Balun Research Articles

A 60-GHz SiGe Power Amplifier With Three-Conductor Transmission-Line-Based Wilkinson Baluns and Asymmetric Directional Couplers

A compact, 60-GHz high-power, wideband balanced power amplifier, implemented in a 90-nm SiGe BiCMOS technology, is demonstrated. A three-conductor transmission-line-based asymmetric coupled-line directional coupler is used to achieve impedance transformation and quadrature power combining simultaneously. A Wilkinson balun based on a three-conductor transmission line structure is implemented to achieve a four-way series-parallel power combining. Analyses of the three-conductor asymmetric coupler and the Wilkinson balun combiner are provided in this article. The design achieved 17.3-dB small-signal gain, with 41.8-GHz 3-dB bandwidth, from 28.1 to 69.9 GHz. A 24.4-dBm saturated output power (PSAT) was measured at 60 GHz with a 22-GHz 1-dB P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SAT</sub> bandwidth, covering 45-67 GHz. The circuit showed a peak power-added efficiency (PAE) of 14.2% at 60 GHz, and the peak PAE is above 11.5% across the 1-dB P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SAT</sub> bandwidth. The proposed eight-way power combining scheme achieves 0.077-mm2 per-way area consumption and 449-mW/mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> power density.

Size and Harmonic Reduced Wilkinson Balun Using Parallel Coupled Line with Open Stub

In this paper, a size-reduced Wilkinson balun with wide harmonic-suppressed band is presented. An accurate analysis of the parallel coupled line with an open stub (PCL-OS) is carried out. The PCL-OS structure shows excellent low pass filter and harmonic- suppression characteristics, which is useful for designing a low pass filter unit cell (LUC) with a reduced size. The designed Wilkinson balun at a 2.45 GHz center frequency not only shows an excellent harmonic suppression including the 5th harmonics up to 14 GHz over 15 dB, but it also has an area reduced to 48% of the conventional one.

Dual‐band microstrip‐to‐coplanar stripline Wilkinson balun using composite right‐ and left‐handed transmission lines and its application in feeding dual‐band bow‐tie antenna

Using a composite right- and left-handed transmission lines, a dual-band microstrip-to-coplanar stripline balun is proposed that presents the benefits of bandwidth enlargement, excellent isolation and equal power split between output ports in the two passbands. Also, the dual-band nature of the balun, close space between output ports and ease of integration with a printed antenna in a compact size make it well suited for feeding dual-band planar two-wire antennas. As an example of an application, the proposed balun is designed and fabricated to work at two arbitrary frequency bands, 0.9 and 1.8 GHz. There is a good agreement between the measured and predicted results, which verifies the proposed design methodology. The fabricated balun shows a measured differential output phase bandwidth (180° ± 10°) of 22.95% and 18.76% for the first and second frequency bands, respectively. Moreover, this device is shown to have enhanced bandwidth performance in both isolation and 3-dB magnitude balance. To validate the performance of the proposed balun, the balun is employed to feed a dual-band metamaterial-loaded bow-tie antenna. The experimental results show that the return losses for both the operating bands remain below 10 dB. Likewise, the dual-band bow-tie antenna provides quasi-omnidirectional radiation over the frequency bands.

Broadband Wilkinson balun using pure left-handed transmission line

Utilizing the opposite phase shift property of a microstrip line (MSL) and a pure left-handed transmission line (PLH TL), the broadband Wilkinson balun is designed.The PLH TL without a right-handed (RH) branch is designed using effectively negative elements obtained by a cross connection of vias to ground. The PLH TL gives inherently phase-advanced response properties because of negative phase velocity, whereas a conventional MSL has a phase-lag response. The property of a broadband left-handed branch of a PLH TL applies to the implementation of broadband balun. The proposed balun has a good return loss, a good isolation between output ports, an equal-power division, and a 180° ± 10° phase difference in a wide fractional bandwidth of ∼71%. Furthermore, the wideband balun that has the fractional bandwidth of 107.8% is theoretically designed with the modified PLH TL having four unit cells. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1665–1668, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25242

Design of a broadband balun based on composite right/left handed structure

AbstractA new printed Wilkinson balun based on the nonlinear phase characteristics of composite right/left handed (CRLH) structure is presented.The new device, which differs from the traditional CRLH balun, is composed of a Wilkinson power divider, a distributed CRLH transmission line (TL), and a conventional TL. It can be easily applied to MIC/MMIC circuits. Full‐wave simulations and measurement results verify the effectiveness of the new structure. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1310–1313, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25189

CPW 월킨슨 발룬을 이용한 CPW 평형증폭기 설계

본 논문은 종래의 CPW 월킨슨 발룬을 이용하여 CPW 평형증폭기를 구성하는 방법을 제안한다. 평형증폭기 구성에 필요한 전력분배/결합구조에 CPW 월킨슨 발룬 구조가 이용된다. 일반적인 경향처럼 CPW 단일증폭기의 정합 특성이 매우 나빴음에 비하여, 제안한 CPW 평형증폭기는 입출력측 모두 우수한 정합특성 개선을 보인다. CPW 단일 증폭기의 정합특성이 매우 나쁜 것에 비하여, -10dB 이하의 입,출력 정합특성을 보이는 CPW 평형증폭기의 주파수 대역은 각각 <TEX>$1.2{\sim}2.75GHz$</TEX>, <TEX>$1{\sim}3.25GHz$</TEX>이다. This paper presents a method to design CPW (coplanar waveguide) balanced amplifiers using the existing CPW wilkinson balun. In order to realize the required power dividing/combining structure for balanced amplifiers, the CPP wilkinson balun is adopted. The proposed CPW balanced amplifier has much better matching performances than the CPW single-ended amplifier. The measured frequency bands, where the input and output reflection coefficients are less than -10dB, are <TEX>$1.2{\s</TEX><TEX>im}2.75GHz$</TEX> and <TEX>$1{\sim}3.25GHz$</TEX>, respectively, while the CPW single-ended amplifier has severely bad ones.

E-band Wilkinson balun using CPW MMIC technology

A simple balun having the structure of a Wilkinson divider is proposed, and a 77 GHz CPW balun, as an example, has been fabricated and measured. The input and output ports of the proposed Wilkinson balun form the desirable inline structure. Results show that the measured S/sub 21/, S/sub 31/, matching, and isolation are -4.5 and -3.7 dB, less than -15 and -20 dB with the exact out of phase between output ports.