Marchand balun provided with center tap and used for providing direct-current bias

Abstract

The invention provides a Marchand balun provided with a center tap and used for providing direct-current bias, which particularly comprises three parts including a primary side, two secondary sides and a de-coupling capacitor, wherein the primary side utilizes a bottom-layer metal layer of a double-layered metal printed circuit board; one end of the primary side is an input and the other end of the primary side is an open circuit; the two secondary sides utilize top-layer metal layers of the double-layered metal printed circuit board; and the widths of metal lines of the secondary sides are the same as the width of the primary side and the metal lines and the primary side are on the same vertical plane to form a wide-edge coupling line. One ends of the two secondary sides are outputs, and one ends which are not output ends are connected to form a center tap and are respectively connected with a capacitor 1 and a capacitor 2; and the other ends of the capacitor 1 and the capacitor 2 are grounded. The Marchand balun further can be manufactured by a manufacturing process of a multi-layered circuit board or an integrated circuit. Compared with the traditional Marchand balun, the Marchand balun disclosed by the invention not only can save the size, but also provides a direct-current bias access for a circuit; and a circuit design is simplified.

Description

technical field [0001] The present invention belongs to the field of information technology. Background technique [0002] At present, the differential structure is widely used in the design of microwave and millimeter wave symmetrical circuits because it can effectively suppress harmonics and reduce noise. As an unbalanced to balanced (single-ended to differential) device, a passive balun is an important part of a differential circuit. The types of passive baluns are mainly divided into transformer baluns, Marchund baluns and transmission line baluns, among which the first two are more commonly used. [0003] In a microwave amplifier circuit with a differential structure, in order to reduce the circuit size, a transformer is usually used as a balun with a center tap. The transformer balun can provide DC bias for active devices in the circuit through the center tap on its secondary side. Compared with the transformer balun, the Machunde balun has a wider bandwidth, but bec...

AI Technical Summary

Problems solved by technology

Compared with the transformer balun, the Marchunde balun has a wider bandwidth, but because of the planar structure, the Marchunde balun must pass through the metal bridge of other layers to do the center tap, and this will inevitably reduce the performance of the balun

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