Broadband subminiature coupler based on folding lines and unequal-width coupling three lines

Abstract

The invention discloses a broadband subminiature coupler based on folding lines and unequal-width coupling three wires, which is constructed on a single-layer printed circuit board, the top layer is a designed coupler circuit structure, the middle layer is a microwave dielectric plate, and the bottom layer is a metal ground; the coupler circuit comprises four ports, two coupling folding transmission lines and a three-wire coupling transmission line. According to the invention, by using the folding lines and the multi-line coupling structure, a wider bandwidth is realized with a smaller size, and the problems of large size and narrow bandwidth of a traditional 90-degree coupler are solved. As a basic part of a radio frequency front end, compared with a traditional solution, the coupler provided by the invention can realize the same bandwidth by using a circuit area smaller than 2-3 times. The circuit is small in size, low in cost and wide in application; the circuit is simple in structure, easy to design and convenient to process and manufacture; the circuit structure is planar, can be processed by a single-layer circuit board, and is easy to integrate.

Description

technical field [0001] The invention belongs to the electrical field, and relates to a passive radio frequency device, in particular to a broadband ultra-miniature coupler based on folded lines and non-equal-width coupled three-lines. Background technique [0002] Traditional couplers mainly include quadrature couplers and ring couplers, which have phase shifts of 90 degrees and 180 degrees respectively, and are key circuit elements in all wireless communication systems. In addition, couplers with a 90-degree phase shift are also widely used in some balanced mixers, antenna feed networks, and power amplifiers. [0003] With the pursuit of broadband, miniaturization and integration of devices in wireless communication products and radar products, it is of great application value and practical significance to develop miniaturized, broadband and easy-to-integrate couplers on planar circuit boards. Traditional couplers are bulky, narrow bandwidth and complex to manufacture. In...

AI Technical Summary

Problems solved by technology

Using a variety of different types of coupling structures is another common way to broaden the bandwidth. For example, although the Lange coupler has a strong coupling degree, its practicability is poor.

Other methods such as using coupled lines to replace part of the branch lines, port cascaded broadband matching circuits and other technologies, although such technologies can increase the bandwidth of the coupler to a certain extent, but their size still has a large limit

In addition, the coupler based on dielectric integrated waveguide technology is now facing difficulties such as high production cost, complicated processing technology and difficulty in integration.

The bandwidth of existing miniaturized couplers is still relatively narrow

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