Hybrid Coupler (hybrid + coupler)

Distribution by Scientific Domains


Selected Abstracts


Design and measurement of microstrip ferrite coupled line circulators

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 3 2001
C. S. Teoh
Abstract The design of microstrip ferrite coupled line (MFCL) circulators using normal mode theory and the first proof-of-principle experiments are described. The longitudinally magnetized ferrite slab is positioned on top of a pair of microstrip lines to form the FCL and this is used with a T -junction and a novel hybrid coupler to form a three-port and a four-port circulator, respectively. The results show MFCL circulator behavior for the first time, and impedance levels and discontinuities are discussed. © 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11: 121,130, 2001 [source]


Dual-band hybrid coupler with extended bandwidth

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2010
King Yin Cheung
Abstract A dual-band branch-line quadrature coupler with extended bandwidth using simple three-section branch line is presented. This proposed design exhibits larger bandwidth than existing dual-band designs reported in previous literature. A dual-band branch-line coupler was designed and measured to give 34.5 and 16.4% bandwidth in the lower band and upper band, respectively, for an amplitude imbalance less than 1 dB. The achieved bandwidth is wide enough to cover wireless local area network and wideband code division multiple access applications. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 2095,2098, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25405 [source]


Fully embedded lumped LC-quadrature hybrid coupler into organic packaging substrate for power sampling

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2009
Yi Jae Lee
Abstract In this article, fully embedded lumped LC-quadrature hybrid coupler are designed, fabricated, and characterized into multilayered organic packaging substrate. This embedded device comprised high Q MIM capacitors and circular spiral stacked inductors. For realizing fully embedded high Q capacitor, barium titanate (BaTiO3) composite high dielectric film was utilized. The measured return loss and isolation were better than 25 dB. Measured insertion loss was about 0.38,0.42 dB at the frequencies ranged from 824 to 894 MHz. The coupler exhibited a coupling loss of 23.3,24 dB. The phase error between through and coupling ports was 1.2°,2.4°. It has a size of 2.8 mm ×2.95 mm ×0.77 mm (height), which is the smallest one in the couplers developed onto the packaging substrate. The measured performance characteristics were also well matched with the 3D EM simulated ones. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 845,848, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24173 [source]


A compact wideband parallel-strip 180° hybrid coupler

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2008
L. Chiu
Abstract In this study, a wideband compact parallel-strip 180° hybrid coupler with the center frequency of 2 GHz is presented. By replacing the 270° section in the 180° hybrid coupler with a parallel-strip phase reversal swap, the total circuit size is reduced by half. In this structure, the phase gradients of the four arms of the coupler are equalized; therefore, the operation bandwidth is dramatically enhanced. S-parameters of the coupler are simulated and measured with good agreement. As predicted from the measured data, the bandwidth of the 90% combining efficiency is increased from 45 to 124%. The proposed design achieves more than ,25 dB signal suppression within the whole measured frequency range (0,4 GHz) as opposed to 1.8 to 2.2 GHz of the conventional design. The proposed 180° hybrid coupler can serve as a wideband in-phase/differential power divider/combiner, which are essential for many RF and microwave subsystem designs. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3271,3274, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23926 [source]


A 5.5-GHz SiGe HBT Doherty amplifier using diode linearizer and lumped-element hybrid coupler

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2008
Haiwen Liu
Abstract A 5.5-GHz Doherty amplifier using commercial 0.35-,m SiGe HBT technology is proposed in this article. To improve the linearity, a predistortion using diode linearizer is adopted for biasing the peak amplifier. Moreover, to realize in fully on-chip with circuit reduction, a 90° 3-dB hybrid coupler and quarter-wave transmission lines are implemented by lumped-elements. In this design, 819 ,m2 HBTs are used for carried and peak amplifiers, respectively, and 26 ,m2 HBT is used for linearizer. Results verify that the power gain, P1dB, and power added efficiency (PAE) of the proposed Doherty amplifier at 5.5 GHz are 8.4 dB, 31 dBm, and 30%, respectively. Also, the adjacent channel power ratio (ACPR) and the output signal's spectrum mask are given using the 54Mcps 64QAM modulated signal at 10 MHz offset. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1554,1558, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23432 [source]


Noise in lossless microwave multiports

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 2 2004
Q. García-García
Abstract This article addresses the noise behaviour (noise temperature and noise figure) of some passive microwave multiport circuits. The analysis method is based on the noise-wave formulation. With the exception of the attenuator case, which is used as a reference, the circuit elements considered are lossless devices, in the sense that neither conductive nor dielectric losses are accounted for. The analysis shows that, when connected to matched loads in some of their ports, these multiports circuits lose their lossless nature and their scattering matrix is not unitary; therefore, they generate thermal noise. The article addresses and formalizes mathematically the noise properties of a number of lossless microwave devices such as N -port power splitters, circulators, and hybrid couplers. While the noise-wave mathematical formulation may be cumbersome in some cases, all the devices and configurations analyzed in this work have been characterized in terms of noise figure and noise temperature, which is a much more practical approach in most situations. Some implications of the use of these devices and configurations in antenna arrays for antenna noise temperature evaluations have been also addressed. © 2004 Wiley Periodicals, Inc. Int J RF and Microwave CAE 14, 99,110, 2004. [source]