RU2340050C1 - Quadrature directional coupler - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention is designed to solve the problem of obtaining 90° phase shift between forward and derived channel of quadrature directional coupler with face coupling. Three-strip quadrature directional coupler with face coupling designed on the three-layer substrate with inner conductor layer-to-layer junction to pad cap layer and with upper conductor layer-to-layer junction to buried layer on the centre of coupled lines.

EFFECT: design is processing tolerant and provides access to two conducting lines.

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Description

The invention relates to the field of radio engineering, and more specifically, to microwave directional couplers and can be used in broadband receiving, transmitting and measuring microwave devices.

The invention is aimed at solving the problem of obtaining a 90 ° phase shift between the direct and branch channels of a quadrature directional coupler (CCW) with a face coupling, implemented on a three-layer structure, the design of which is resistant to technological accuracy and provides access to two conductive lines.

Known double-band FWM with front coupling (M. D. Prouty, S.E. Schwarz. Hybrid Couplers in Bilevel Microstrip. IEEE Transactions on microwave theory and techniques, vol. 41, No.11, November 1993, p.1939-1944) implemented on a three-layer structure in which a 90 ° phase shift is achieved by connecting additional phase shifters to the two sides of the CCW.

The disadvantages of such a CCW are:

- the need to connect additional phase shifters, aligning the phase of the segments of the connected lines with front communication, which increase the overall dimensions of the device;

- the complete lack of accessibility to the two conductive lines needed to configure the device;

- a strong influence of technological tolerance on the combination of layers of the device board.

Known four-strip KNO (US Patent: No. 7009467 B2) with front communication, implemented on a three-layer structure, which provides access to two conductive lines and resistance to technological accuracy.

The disadvantage of such a CCW is the design complexity and the need to connect additional phase motors to ensure a phase shift of 90 °.

Also known is the three-strip SLC (Andrzej Sawicki, Krzysztof Sachse. Quase-Ideal Multilayer Two- and Three-Strip Directional Couplers for Monolithic and Hybrid MIC's // IEEE Transactions on microwave theory and techniques. - 1999, Vol. - 47 - No. 9 - September. - P.1873 - 1888) with a face connection, implemented on a three-layer structure, adopted as a prototype, which is a two-strip KNO, the upper conductor of which is split into two conductors.

Such a CCW is more resistant to technological accuracy, but requires the addition of additional phase shifters to obtain a 90 ° phase shift and ensure accessibility to the inner conductor.

The aim of the invention is the implementation of the CCW on a three-layer structure, without additional phase shifters, which provides access to two conductors of connected lines, the design of which is resistant to technological accuracy.

To achieve this goal, a three-strip KNO with a face bond, made on a three-layer structure, is proposed.

According to the invention, it contains two identical sections of connected lines with a face bond of length λ / 8, which are connected so that the upper conductor of the first section of connected lines is connected through an interlayer transition to the inner conductor of the second section of connected lines, and the internal conductor of the first section of connected lines is connected through interlayer transition to the upper conductor of the second section of connected lines.

The combination of distinctive features and properties of the proposed KNO from the literature are unknown, therefore, it meets the criteria of novelty and inventive step.

Figure 1 presents the functional diagram of the device, figure 2 - the structure of the layers of the CCW, figure 3 - the topology of the CCW.

The CCW contains two identical sections of connected lines with a front connection, consisting of conductors 1 and 2. A two-strip conductor 1 of the first section, λ / 8 length and strip width w with a gap between them s, located on the outer layer 3 of height h, passes through the interlayer transition 4 to the inner layer 5 with a height H of the second section into a single-strip conductor 1 of length λ / 8 and a strip width W. The single-strip conductor 2 of the first section of the CCW, of length λ / 8 and width W, located on the inner layer 5, passes through the interlayer transition 4 to the outer layer 3 second section and wherein the conductor 2 - is dvuhpoloskovy λ / 8 length and width w of striplines with a gap therebetween s. The reverse side of structure 6 is solid metallization.

A distinctive feature of the work of the claimed CCW from the known CCW on connected lines with face communication is to ensure the same propagation conditions for the two existing modes. The phase deviation of 45 ° + Δφ in the first section of the CCW is compensated in the second section of the CCW, where the phase incursion of 45 ° -Δφ is ensured. As a result, the phase difference between the direct and branch channels is 90 ° = (45 ° + Δφ) + (45 ° -Δφ).

A mock-up of a quadrature directional coupler was made using the Low Temperature Co-fire Ceramic (LTCC) technology, designed to operate in the L-wavelength band with a frequency overlap of 2.26: 1. The phase shift deviation from the required was no more than ± 2 °, VSWR of inputs / outputs no more than 1.25. The attenuation of the signal in each channel is not more than 0.3 dB, the non-identity of the transmission coefficient is ± 0.5 dB.

Claims (1)

A quadrature directional coupler with a front connection made on a three-layer structure, characterized in that it contains two identical sections of connected lines with a front connection of length λ / 8, which are connected in such a way that the upper conductor of the first section of the connected lines is connected through an interlayer transition to the inner conductor the second section of the connected lines, and the inner conductor of the first section of the connected lines is connected through an interlayer transition to the upper conductor of the second section of the connected lines.

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