RU2745363C1 - Method for minimizing the control currents of the phase control system of headlamp control - Google Patents

Abstract

FIELD: antennas.

SUBSTANCE: invention relates to antenna technology, in particular to phased antenna arrays, and can be used to minimize currents in switched antenna array phase shifters. The technical result is achieved in that the same phase shift is added to all radiating elements, while the position of the beam in space does not change, and the added phase shift provides a minimum number of switching p-i-n elements, thereby significantly reducing the consumption of switching currents, while the phase addition is introduced programmatically or using a phase shifter common to all elements of the PAA.

EFFECT: decreased control current in the phase shifters of the PAA control circuit.

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Description

The invention relates to radar, namely to phased antenna arrays (PAR), and can be used to minimize currents in the switched phase shifters of the antenna array. The control switching currents in phased array phase shifters with a large number of elements reach tens, hundreds or more amperes, depending on the specified parameters of the phased array: gain, range of angles and beam scanning law, beam width, etc., including the number of emitters and applied circuits phase shifters.

This means that both the radiation power and the power used to control the PAA are large enough. In multi-element HEADLIGHTS, the control power can be many times higher than the radiated power. Powerful sources of electrical energy are required, and this is both weight and volume. While this is tolerable in ground-based radars with HEADLIGHTS, this creates problems in small and medium-sized aircraft, which is especially true for unmanned aerial vehicles (UAVs) of the middle class (up to 1000 kg and more) and underwater drones in the HEADLIGHTS of sonars.

The technical problem of the invention is to significantly reduce the control current in the phase shifters of the PAA control circuit.

The technical result is achieved by applying the same phase addition to all phased array phase shifters, determined at the design stage from the condition of minimizing simultaneously switched on diodes. In this case, the position of the beam does not change, the number of simultaneously switched on pn diodes in each phase shift is reduced.

To solve this problem, a method is proposed for minimizing the control currents of the phase shifters of the PAA control circuit, based on phased directional radiation, characterized by the fact that the same phase shift is added to all radiating elements, while the position of the beam in space does not change, and the added phase shift provides the minimum number of switching pin elements, thereby significantly reducing the consumption of switching currents. The required phase distribution is set by the phase shifter control circuit.

Taking into account the fact that in traditionally used N-bit phase shifters using pin diodes, the required phase shift in the range from 0 to 360 degrees is set with a step of 360 / N, and the state of the diodes in each of the N cells can be closed reverse voltage or open forward current , diode opening currents are not linearly dependent on the set phase shift. The number of open diodes can vary from 0 to 2N if two p-i-n diodes are used in each of the cells. Electrical scanning of the antenna array beam is carried out by setting the required phase shift to each of the radiators of the antenna system.

FIG. 1 shows a linear phase distribution, which shows:

1 - HEADLIGHT cloth

2 - directional diagram (DP) for one phase shift

3 - flat excitation front (approximation)

4 - steps of a flat excitation front (without phase addition)

5 and 6 - steps of the phase addition

FIG. 2 shows a diagram of the currents of one phase shifter depending on the set phase shift in degrees (the diagram corresponds to a 4-bit phase shifter with a phase shift of 22.5 degrees). It is assumed that the turn-on current of one p-i-n diode is 20 mA.

FIG. 3 shows the distributions of control currents in a round PAR, consisting of 308 elements for the same angle of inclination of the main lobe (in this case 15 degrees), but with a different phase addition to all phase shifters (20 degrees in Fig. 3, a and 50 degrees in Fig. 3, b). The difference in the control current was 10.5%. For a phased array of a square shape, the difference increases.

It can be seen that the idea of optimal PAA control from the point of view of minimizing the current of the switched phase shifters is very relevant.

Any scanning antenna array consists of a group of emitters located in a certain way on the web, which are phased in a predetermined manner to form directional radiation in the required direction. To deflect the beam at the theta and phi angles, the formed flat excitation front must be perpendicular to the direction of radiation (Fig. 1).

The linear phase distribution is approximated in the form of steps, the position of which is closest to the required slope of the wave front. The size of the steps is determined by the phasing discrete of the phase shifters (22.5 or 45 or other degrees). Switching of cells most often occurs using p-i-n diodes. At zero bias, all diodes are off and the control current is zero. With a shift equal to the phasing sample, one cell is turned on (for example, 2 diodes). To shift in two steps, another cell is turned on (again 2 diodes). For a shift of 3 steps, the first and second cells (4 diodes) are turned on, for a shift of 4 steps, one cell with 2 diodes is turned on, etc. Those. the number of switched on diodes depends nonlinearly on the required phase shift, and therefore on the switching current (Fig. 2).

If the same phase shift is added to all the emitting elements, the position of the beam in space will not change (dashed steps in Fig. 1). However, in this case, it is possible to select such a phase addition that will provide the minimum value of the control current in the phase shifters of the PAA control circuit. This additive can be introduced both programmatically and using a phase shifter common to all the PAR elements.

For example, for a PAA of 308 elements, with the condition of beamforming at an angle of 15 degrees to the normal of the antenna aperture and using 4-bit PV (with 4 cells), the value of the control current varies from 26.2 to 23.7 A, provided that each diode commutated with a current of 20 mA. The savings are 10.5%.

Claims (1)

A method for minimizing the control currents of phase shifters of a phased array control circuit, based on phased directional radiation, characterized in that the same phase shift is added to all radiating elements, while the position of the beam in space does not change, and the added phase shift provides a minimum number of switching pin elements , thereby significantly reducing the consumption of switching currents, while the phase addition is introduced programmatically or using a phase shifter common to all elements of the phased array.

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