RU2490757C2 - Discrete transmission phase shifter - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: in a discrete transmission phase shifter, having a waveguide along the axis of which, in the cross-section, there are dielectric plates with asymmetrical planar coupling loops and control electrodes and p-i-n diodes connected thereto, the waveguide has a flat-topped cross-section, and the dielectric plates with planar coupling loops are located between a protrusion and the side wall of the flat-topped waveguide, and the p-i-n diodes are connected to the ends of each loop.

EFFECT: smaller cross dimension of the phase shifter and wider operating bandwidth of the phase shifter.

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Description

The alleged invention relates to the field of microwave electronics, namely, discrete pass-through phase shifters, and can be used as electronically controlled devices in a pass-through phased array antenna.

A known design of a loop-through loopback phase shifter [Khizh GS, Vendik IB, Serebryakova EA, Microwave phase shifters and switches, 1984]. The loopback phase shifter is a segment of the transmission line, which is loaded on both sides to the same parallel conductivity. Reactivity is realized by parallel loops, loaded at the end of the line to a p-i-n-diode. In the place of connecting the loops to the main line, a transformer is formed. The loop connection area is described by a six-terminal, to which a two-terminal is also connected - a single-stage reflective phase shifter. The change in the phase of the transmission coefficient is carried out by switching periodically included in the line cables.

The disadvantages of this phase shifter in the waveguide design are large transverse dimensions and mass.

A microwave phase shifter device is also known [RF patent No. 2032254, IPC: H01P 1/185]. The essence of the invention: in the microwave phase shifter containing the controlled phase shifter and the first and second 3-dB bridges connected through the first and second loop-through phase shifters, with one output arm of the second 3-dB bridge is the first output of the microwave phase shifter, the loop-through phase shifters are made with a 0- phase shift 180 °, the controlled phase shifter is connected to the first input arm of the first bridge - the first input of the microwave phase shifter, the second input shoulder of the first bridge is the second output of the microwave phase shifter.

The disadvantages of this device is a structurally complex design due to the introduction of a 3-dB bridge, in which, to obtain large phase shifts, the power coming from the first and second pass-through discrete phase shifters is combined, as well as the large transverse dimensions and mass in the waveguide design, which limits its use in composition of phased antenna arrays.

Closest to the proposed invention is a discrete feedthrough phase shifter [Pazukhina TG, Sivyakov B.K. Design of waveguide phase shifters with p-i-n-diodes and planar communication loops / Bulletin of the Saratov State Technical University. 2008. No. 1. Issue 1. S.246-255]. The phase shifter contains a segment of a rectangular waveguide and “N” coupling loops located on dielectric plates mounted in the transverse section of the waveguide, p-i-n diodes are connected by one electrode to the ends of the communication loops, and the second to a narrow wall of the waveguide. The phase shifter consists of several identical sections. Each section consists of a set of series-connected elementary phase-shifting cells containing two reactive elements.

The disadvantages of this device are the impossibility of reducing the transverse size of the waveguide to less than the length of the electromagnetic wave in free space, necessary to increase the viewing angle of the phased antenna array, and the relatively narrow passband of a rectangular waveguide.

The objective of the invention and the technical result is to reduce the transverse size of the phase shifter and expanding the operating frequency band of the phase shifter.

The problem is achieved in that in a discrete pass-through phase shifter containing a waveguide, along the axis, in which a dielectric plate with asymmetric planar coupling loops and control electrodes and pin diodes connected to them, each of which is connected to the end of an asymmetric planar one electrode the communication loop, and the other electrode to the side wall of the waveguide according to the proposed technical solution, the waveguide has a U-shaped cross section, and dielectric plates with asymmetric planar hinge connection disposed between the projection and the sidewall of the U-shaped waveguide, and each p-i-n-diode is connected to one electrode of the asymmetric planar end loop in the wide U-shaped wall of the waveguide opposite to the protrusion.

The proposed device is illustrated by drawings: figure 1 shows a schematic design of a phase shifter, figure 2 - its longitudinal section, figure 3 - phase-frequency characteristics,

where 1 is a segment of a waveguide of a U-shaped section;

2 - dielectric plates;

3 - asymmetric planar communication loop;

4 - p-i-n-diodes;

5 - control electrode.

The discrete pass-through phase suppressor consists of a segment of a U-shaped waveguide 1, along the axis of which dielectric plates 2 with asymmetric planar coupling loops 3 are placed in cross section. Dielectric plates 2 are located one after the other between the protrusion and the side wall of a segment of the U-shaped waveguide 1 and separated from each other at a distance of a quarter of the wavelength in such a waveguide. There is a gap between the dielectric plates 2 and the side wall of the waveguide. The dielectric plate 2 coated with an asymmetric planar coupling loop 3 is a reactive element. Reactive quarter-wavelength reactive elements form an elementary phase-shifting cell. The number of phase-shifting cells determines the discreteness of the phase shifter. Asymmetric planar coupling loops 3 are placed on the dielectric plates 2, so that at the junction of the two phase-shifting cells, asymmetric planar coupling loops 3 are located on both sides of the dielectric plate 2. Thus, there are dielectric plates with one planar coupling loop at the input and output. The planar coupling loop 3 is an asymmetric design in which one end is loaded with a p-i-n-diode 4 near the wide wall of the U-shaped waveguide 1 opposite the protrusion, and the other remains open. The electrical length of the unloaded end of the asymmetric planar coupling loop 3 (counting along the midline from the plane of symmetry of the loop) is approximately 90 °. Each p-i-n-diode 4 is connected by one electrode to an asymmetric planar coupling loop 3, and the other to the side wall of the waveguide. The control electrode 5 serves to supply a control voltage to the p-i-n-diodes 4, which is connected to the Central part of the asymmetric planar coupling loop 3.

The device operates as follows.

The discrete pass-through phase shifter changes the phase of the electromagnetic wave, which is directed from the irradiator. The state when all p-i-n-diodes 4 are off is considered to be zero and the phase change is counted from it. The elementary phase-shifting cells are connected in series. Each reactance can take two values depending on the polarity of the voltage applied to the p-i-n-diodes 4, which are included in the circuit of each reactivity in series with it. When applying a blocking voltage to the pin diodes 4 via the control electrode 5, the circuit of the asymmetric planar coupling loop 3 will be open for microwave currents, since in this case the pin diodes 4 will be closed, and the asymmetric planar coupling loop 3 will not disturb the magnetic field . When applying direct bias voltage to p-i-n-diodes 4, p-i-n-diodes 4 will open. A current flows through the asymmetric planar loop 3 circuit, which creates a demagnetizing current. The phase of the transmitted wave is defined as the phase difference of the transmission coefficients of Si2 in two states of the unit cell. When you turn on the first cell

, где N - число фазосдвигающих ячеек. При каждом включении следующей ячейки фаза увеличивается с дискретом $$\frac{360°}{N}$$

.gear ratio phase changes to $$\frac{360°}{N}$$

where N is the number of phase-shifting cells. Each time the next cell is turned on, the phase increases with a discrete $$\frac{360°}{N}$$

.

From the phase-frequency characteristics of the phase shifter calculated by the Ansoft HFSS electrodynamic modeling software package for 16 phase positions (Fig. 3), it can be seen that the phase-frequency characteristics have a relatively weak dispersion in the frequency band with a discrete of 22.5 °.

Reducing the transverse dimensions makes it possible to put the phased array antenna modules closer to each other, thereby increasing the viewing sector angle of the phased array antenna space.

Claims (1)

A discrete pass-through phase shifter containing a waveguide, along the axis of which dielectric plates with asymmetric planar coupling loops and control electrodes and pin diodes connected to them, each of which is connected to the end of the asymmetric planar coupling loop and the other electrode to the side the waveguide wall, characterized in that the waveguide has a U-shaped cross section, and dielectric plates with asymmetric planar coupling loops are located between the blunt and side wall of the U-shaped waveguide, and each p-i-n-diode is connected by one electrode to the end of the asymmetric planar coupling loop near the wide wall of the U-shaped waveguide, opposite the protrusion.

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