| The directional coupler is a commonly used microwave millimeter wave components, it can constitute a power divider, power synthesizer, multi-channel synthesizer, phase shifter and attenuator and so on.With the extensive application in microwave distribution system, antenna feed network, the power of microwave synthesis and microwave test system, the directional coupler is an important part of many microwave circuits and systems. The 3d B quadrature coupler is a special kind of directional coupler with 90 degree phase differences between input and output.With the development of communication technology, the directional coupler are now in great demands. The constrains on broad band and limited size is usually as same importance as it on reliability. VHF/UHF is an important band in military application. The main purpose of this paper is to develop a method for the VHF/UHF(30MHz to 512MHz) miniaturized ultra wideband 3d B quadrature coupler. In the prior art, for ultra wideband 3d B quadrature coupler V/U band mainly using the lumped parameter method, although the lumped parameter directional coupler technology is mature, parameters of excellent, but it has the difficulty of debugging, high production cost, discrete index and not suitable for high-volume production problems. In this paper, the theory on the strip line based on the analysis, using the technology of stripline directional coupler, through investigation and Research on the current sheet parameters, explore the screening and physical design, formed a set of simulation by ADS design of stripline method. Through research on the plate stripline coupler directional characteristics, cascade characteristic and shape of the miniaturization of stripline directional coupler processing, directional coupler new ultra bandwidth 3d B Quadrature strip line structure is proposed for the band, Rogers high frequency plate with high dielectric constant, single strip line and the five section band line cross cascade way, folding constitute special stripline structure similar to "王" shape of the directional coupler, and in the folded strip line in the circumstances to ensure the orthogonality of the directional coupler.This paper realized the simulation schematic and PCB layout, and make real, to evaluate physical parameter, and has been applied to the VHF/UHF high power adaptive interference cancellation system. The new ultra wideband 3d B stripline directional coupler proposed in this paper, a simple debugging, low manufacturing cost and small discrete index can be mass production. Compared with the existing stripline technology for small processing and optimization of parameters.In this paper,there is a certain gap between the simulation parameters and the real directional coupler, we have analyzed the causes of the error. According to the design and simulation thought of this paper, there is a large space for each index of the stripline directional coupler for further improvement.In this paper,there is a certain gap between the simulation parameters and the real directional coupler, we have analyzed the causes of the error. According to the design and simulation thought of this paper, there is a large space for each index of the stripline directional coupler for further improvement.In this paper the new kind of directional coupler with ultra 3d B bandwidth is proposed. When compared with current VHF/UHF lumped parameter directional coupler, in the case of ensuring the device size, our coupler is easier to debug, cost less and has small discrete index, so it can be applied to mass production. Compared with the existing stripline technology we have fulfilled the miniaturization and the optimization of the stripline directional coupler.. |
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