Miniaturized hybrid ring coupler and design method thereof

Abstract

The invention discloses a miniaturized hybrid ring coupler and a design method thereof. A first port is connected with a second port through a first T-shaped transmission line, a third port is connected with a fourth port through a TRD coupling line with two short-circuited ends, a second T-shaped transmission line is bridged between the first port and the third port, and a third T-shaped transmission line is bridged between the second port and the fourth port. According to the miniaturized hybrid ring coupler and the design method thereof, the lambda / 4 TRD coupling line of which the two endsare short-circuited is adopted to replace a 3 lambda / 4 uniform transmission line so that the miniaturized hybrid ring coupler is realized; in order to further reduce the size of the hybrid ring and realize a harmonic suppression function, each lambda / 4 uniform transmission line is replaced by a T-shaped transmission line equivalent circuit. The hybrid ring coupler provided by the invention not only effectively realizes miniaturization, but also has a harmonic suppression function and has relatively large working bandwidth and relatively low design complexity.

Description

technical field [0001] The invention belongs to the technical field of radio frequency microwave circuits, and in particular relates to a miniaturized hybrid ring coupler and a design method thereof. Background technique [0002] The hybrid ring coupler is a four-port network with ideal matching and isolation characteristics. It can not only realize non-inverting and anti-phase output, but also realize signal addition and subtraction functions. Hybrid ring couplers have been widely used in microwave and millimeter wave circuits, such as balanced amplifiers, balanced mixers, and antenna feed networks. However, the traditional hybrid ring coupler contains a 3λ / 4 and three λ / 4 uniform transmission lines, which makes the circuit size larger. [0003] The perimeter of the hybrid ring with a traditional structure is 3λ / 2, which occupies a large circuit size, such as figure 1 shown. In order to reduce the size of the hybrid ring, S.March first proposed to replace the 3λ / 4 transm...

AI Technical Summary

Problems solved by technology

For the transmission line bending method, the reduction in the size of the hybrid ring is mainly determined by the density and the number of nodes of the bent transmission line, but the tight transmission line will produce strong parasitic coupling, which will deteriorate the matching and isolation characteristics of the hybrid ring coupler

For the arbitrary electrical length transmission line method, the λ / 4 transmission line in the traditional hybrid ring can be adjusted to a λ / 8, λ / 6 or 5λ / 36 transmission line, and the final circumference of the entire ring is 5λ / 4, 7λ / 6 and 19λ / 18, but this method can only be used to design 3dB hybrid ring couplers at present

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